feed.xml

<?xml version="1.0" encoding="utf-8"?><feed xmlns="http://www.w3.org/2005/Atom" ><generator uri="https://jekyllrb.com/" version="3.8.5">Jekyll</generator><link href="https://cfrenzel.com/feed.xml" rel="self" type="application/atom+xml" /><link href="https://cfrenzel.com/" rel="alternate" type="text/html" /><updated>2020-03-04T12:26:56-05:00</updated><id>https://cfrenzel.com/feed.xml</id><title type="html">cfrenzel</title><subtitle>Blog of Camron Frenzel</subtitle><entry><title type="html">Throwback: Prototype of AR Furniture Layout (2009)</title><link href="https://cfrenzel.com/augmented_reality_project/" rel="alternate" type="text/html" title="Throwback: Prototype of AR Furniture Layout (2009)" /><published>2020-02-28T00:00:00-05:00</published><updated>2020-02-28T00:00:00-05:00</updated><id>https://cfrenzel.com/augmented_reality_project</id><content type="html" xml:base="https://cfrenzel.com/augmented_reality_project/">&lt;p&gt;Was going through some old video and found rough demo of a prototype that I built back in 2009. I was experimenting with AR at the time but nothing really came of it; so I thought I’d throw it up here.  The prototype uses a webcam under a sheet of glass to track markers on the bottom of blocks.  Here I’m experimenting with the layout of some office furniture.&lt;/p&gt;

&lt;iframe src=&quot;https://player.vimeo.com/video/394464714&quot; width=&quot;640&quot; height=&quot;480&quot; frameborder=&quot;0&quot; allow=&quot;autoplay; fullscreen&quot; allowfullscreen=&quot;&quot;&gt;&lt;/iframe&gt;

&lt;iframe src=&quot;https://player.vimeo.com/video/394463597&quot; width=&quot;640&quot; height=&quot;853&quot; frameborder=&quot;0&quot; allow=&quot;autoplay; fullscreen&quot; allowfullscreen=&quot;&quot;&gt;&lt;/iframe&gt;</content><author><name>camron</name></author><category term="creative" /><category term="development" /><summary type="html">Was going through some old video and found rough demo of a prototype that I built back in 2009. I was experimenting with AR at the time but nothing really came of it; so I thought I’d throw it up here. The prototype uses a webcam under a sheet of glass to track markers on the bottom of blocks. Here I’m experimenting with the layout of some office furniture.</summary><media:thumbnail xmlns:media="http://search.yahoo.com/mrss/" url="https://cfrenzel.com/assets/images/ar_furniture.png" /></entry><entry><title type="html">Throwback: Projector with Microsoft Kinect (2013)</title><link href="https://cfrenzel.com/kinect_and_projector_project/" rel="alternate" type="text/html" title="Throwback: Projector with Microsoft Kinect (2013)" /><published>2020-02-27T00:00:00-05:00</published><updated>2020-02-27T00:00:00-05:00</updated><id>https://cfrenzel.com/kinect_and_projector_project</id><content type="html" xml:base="https://cfrenzel.com/kinect_and_projector_project/">&lt;p&gt;Found some more footage that I thought was pretty cool from back in 2013. This uses a microsoft kinect to track people at a party.  I used Quartz Composer to build some visuals and projected it realtime on the side of a barn.  Some of the visualizations are influenced by the audio, but I never got much going with body tracking.  Might have to expand on this one in the future.&lt;/p&gt;

&lt;iframe src=&quot;https://player.vimeo.com/video/394466517&quot; width=&quot;640&quot; height=&quot;360&quot; frameborder=&quot;0&quot; allow=&quot;autoplay; fullscreen&quot; allowfullscreen=&quot;&quot;&gt;&lt;/iframe&gt;</content><author><name>camron</name></author><category term="creative" /><category term="development" /><summary type="html">Found some more footage that I thought was pretty cool from back in 2013. This uses a microsoft kinect to track people at a party. I used Quartz Composer to build some visuals and projected it realtime on the side of a barn. Some of the visualizations are influenced by the audio, but I never got much going with body tracking. Might have to expand on this one in the future.</summary><media:thumbnail xmlns:media="http://search.yahoo.com/mrss/" url="https://cfrenzel.com/assets/images/kinect_projector.png" /></entry><entry><title type="html">Learning From Open Source Part1: MediatR</title><link href="https://cfrenzel.com/learning-from-open-source-part1-mediatr/" rel="alternate" type="text/html" title="Learning From Open Source Part1: MediatR" /><published>2020-01-14T00:00:00-05:00</published><updated>2020-01-14T00:00:00-05:00</updated><id>https://cfrenzel.com/learning-from-open-source-part1-mediatr</id><content type="html" xml:base="https://cfrenzel.com/learning-from-open-source-part1-mediatr/">&lt;p&gt;It can be intimidating and time consuming to explore a mature open source project.  Often an attempt to find inspiration results in a surface level understanding of a few components with no real insight into the &lt;strong&gt;magic&lt;/strong&gt;.  In this series I hope to find projects of just the right size and complexity to “get in there” and learn something valuable.  Let’s start by taking a look at &lt;a href=&quot;https://github.com/jbogard/MediatR&quot;&gt;MediatR&lt;/a&gt;.&lt;/p&gt;

&lt;p&gt;I use MediatR in many projects because of its “simple to use” yet powerful implementation of the &lt;a href=&quot;https://en.wikipedia.org/wiki/Mediator_pattern&quot;&gt;Mediator Pattern&lt;/a&gt;.  A mediator sits between method callers and receivers creating a configurable layer of abstraction that determines how callers and receivers get wired up.&lt;/p&gt;

&lt;p&gt;Let’s look at a quick example of a Controller calling some Application Layer code with MediatR.&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;CreateTicketCommand&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;IRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CreateTicketResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;string&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Description&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;set&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;string&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Department&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;set&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;string&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Severity&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;set&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;TicketController&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Controller&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
   &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;readonly&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;IMediator&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_mediator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;TicketController&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IMediator&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;mediator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;_mediator&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;mediator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;HttpPost&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;async&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;ActionResult&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Create&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CreateTicketModel&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;model&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;kt&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;command&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;CreateTicketCommand&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;Description&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;model&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Description&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;Department&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;model&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Department&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;Severity&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;model&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Severity&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;};&lt;/span&gt;

        &lt;span class=&quot;kt&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;res&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;await&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_mediator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Send&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;command&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;RedirectToAction&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Show&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;id&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;res&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TicketId&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;});&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;There are a few things to notice here.&lt;/p&gt;
&lt;ul&gt;
  &lt;li&gt;The Command defines the type of it’s response &lt;code class=&quot;highlighter-rouge&quot;&gt;IRequest&amp;lt;CreateTicketResponse&amp;gt;&lt;/code&gt;&lt;/li&gt;
  &lt;li&gt;The &lt;code class=&quot;highlighter-rouge&quot;&gt;IMediator&lt;/code&gt; is injected into the Controller&lt;/li&gt;
  &lt;li&gt;There is a single &lt;code class=&quot;highlighter-rouge&quot;&gt;Send&lt;/code&gt; method on the &lt;code class=&quot;highlighter-rouge&quot;&gt;IMediator&lt;/code&gt; used to dispatch all command/request types&lt;/li&gt;
  &lt;li&gt;The Controller doesn’t know who is handling the command&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Here’s a sample handler for &lt;code&gt;CreateTicketCommand&lt;/code&gt;&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;CreateTicketHandler&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;IRequestHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CreateTicketCommand&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;CreateTicketResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;readonly&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ApplicationDbContext&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_db&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;CreateTicketHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;ApplicationDbContext&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;db&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt;  &lt;span class=&quot;n&quot;&gt;_db&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;db&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;async&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CreateTicketResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CreateTicketCommand&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;command&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;CancellationToken&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;Ticket&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ticket&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Ticket&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;command&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Description&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;command&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Department&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;command&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Severity&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;_db&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Tickets&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Add&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;ticket&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;await&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_db&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SaveChangesAsync&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;();&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;CreateTicketResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;TicektId&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ticket&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Id&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;};&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;Notice:&lt;/p&gt;
&lt;ul&gt;
  &lt;li&gt;Handler doesn’t know who sent the command&lt;/li&gt;
  &lt;li&gt;Handler specifies the the message type that it handles and the response type &lt;code class=&quot;highlighter-rouge&quot;&gt;IRequestHandler&amp;lt;CreateTicketCommand, CreateTicketResponse&amp;gt;&lt;/code&gt;&lt;/li&gt;
  &lt;li&gt;Handler has constructor parameters that must be injected by the caller&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;We configure MediatR in our app’s startup with a single line&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;  &lt;span class=&quot;n&quot;&gt;services&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;AddMediatR&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Program&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;));&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;Here’s what I’m thinking&lt;/p&gt;
&lt;ul&gt;
  &lt;li&gt;
    &lt;p&gt;I never registered any handlers explicitly; so I know that MediatR is scanning my assembly for handlers.  This is pretty common and shouldn’t be much different than something like ASP.NET MVC finding your controllers, but I’d like to look under the hood a little.&lt;/p&gt;
  &lt;/li&gt;
  &lt;li&gt;
    &lt;p&gt;The call to &lt;code class=&quot;highlighter-rouge&quot;&gt;_mediator.Send(command)&lt;/code&gt; stands out as the interesting bit.  Somehow this method can take any request type, find a concrete handler implementation for that request type, instantiate it, and call it.  Let’s try to uncover the &lt;strong&gt;magic&lt;/strong&gt; behind this!&lt;/p&gt;
  &lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;Going to the Source&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;Let’s dig in.  First download the source or browse online at &lt;a href=&quot;https://github.com/jbogard/MediatR/tree/master/src/MediatR&quot;&gt;https://github.com/jbogard/MediatR/tree/master/src/MediatR&lt;/a&gt;&lt;/p&gt;

&lt;pre&gt;
&amp;gt; git clone https://github.com/jbogard/MediatR.git .
&lt;/pre&gt;

&lt;p&gt;You’ll first notice a handful of simple interfaces and &lt;code class=&quot;highlighter-rouge&quot;&gt;Mediator.cs&lt;/code&gt; with the core class.  Since we’re curious about it’s &lt;code class=&quot;highlighter-rouge&quot;&gt;Send&lt;/code&gt; method let’s take a look inside.  The file is surprisingly small, and at first glance it looks like the &lt;code class=&quot;highlighter-rouge&quot;&gt;Send&lt;/code&gt; method is actually doing some of the real work.&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Mediator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;ServiceFactory&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;serviceFactory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;_serviceFactory&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;serviceFactory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Send&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;CancellationToken&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;default&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;if&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;request&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;==&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;null&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
            &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
                &lt;span class=&quot;k&quot;&gt;throw&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;ArgumentNullException&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;nameof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;));&lt;/span&gt;
            &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

            &lt;span class=&quot;kt&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;requestType&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;GetType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;();&lt;/span&gt;

            &lt;span class=&quot;kt&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;handler&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;RequestHandlerWrapper&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;)&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;_requestHandlers&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;GetOrAdd&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;requestType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;t&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Activator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;CreateInstance&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;RequestHandlerWrapperImpl&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;,&amp;gt;).&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;MakeGenericType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;requestType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;))));&lt;/span&gt;

            &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;handler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_serviceFactory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;First things first, above I made a call using &lt;code class=&quot;highlighter-rouge&quot;&gt;Send(command)&lt;/code&gt;, but the send method here is generic &lt;code class=&quot;highlighter-rouge&quot;&gt;Send&amp;lt;TResponse&amp;gt;(IRequest&amp;lt;TResponse&amp;gt; request)&lt;/code&gt;.  It turns out that the compiler can infer the type argument; so you can omit it.  Our call above looks much prettier than &lt;code class=&quot;highlighter-rouge&quot;&gt;Send&amp;lt;CreateTicketResponse&amp;gt;(command)&lt;/code&gt; &lt;a href=&quot;https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/generics/generic-methods&quot;&gt;(generics methods).&lt;/a&gt;  Moving on…&lt;/p&gt;

&lt;p&gt;I’m starting to get excited because the &lt;code class=&quot;highlighter-rouge&quot;&gt;Send&lt;/code&gt; method is basically a fat one-liner, yet it appears to be instantiating a handler and calling it (which is all a mediator really does).   Let’s dig a little deeper.&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;kt&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;handler&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;RequestHandlerWrapper&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;)&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;_requestHandlers&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;GetOrAdd&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;requestType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;t&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Activator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;CreateInstance&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;RequestHandlerWrapperImpl&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;,&amp;gt;).&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;MakeGenericType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;requestType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;))));&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;The outer &lt;code class=&quot;highlighter-rouge&quot;&gt;_requestHandlers.GetOrAdd&lt;/code&gt; is just checking if a handler already exists before creating a new one. The real magic seems to be:&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;n&quot;&gt;Activator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;CreateInstance&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;RequestHandlerWrapperImpl&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;,&amp;gt;).&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;MakeGenericType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;requestType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)))&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;We’re getting close to something.   We’re taking a &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerWrapperImpl&amp;lt;,&amp;gt;&lt;/code&gt; calling &lt;code class=&quot;highlighter-rouge&quot;&gt;.MakeGenericType(requestType, typeof(TResponse))&lt;/code&gt; on it then instantiating the result, which is apparently assignable to &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerWrapper&amp;lt;TResponse&amp;gt;&lt;/code&gt;.  Let’s plug in our command type above to see what it looks like.&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;RequestHandlerWrapperImpl&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;,&amp;gt;).&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;MakeGenericType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CreateTicketCommand&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;),&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CreateTicketResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;))&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;This gives us a &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerWrapperImpl&amp;lt;CreateTicketCommand,CreateTicketResponse&amp;gt;&lt;/code&gt; which is assignable to &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerWrapper&amp;lt;CreateTicketResponse&amp;gt;&lt;/code&gt;.  For now let’s think of “RequestHandlerWrapper” as some kind of wrapper around our actual handler (&lt;code class=&quot;highlighter-rouge&quot;&gt;CreateTicketHandler&lt;/code&gt;).  We know that instantiating our actual handler will require Dependency Injection to resolve the dependencies (like ApplicationDbContext); so perhaps the wrapper is hiding these details.&lt;/p&gt;

&lt;p&gt;But whats up with the cast from &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerWrapperImpl&lt;/code&gt; down to the less generic &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerWrapper&lt;/code&gt;?  Believe it or not, this seemingly benign cast is part of the real &lt;strong&gt;magic&lt;/strong&gt;.  The bigger concept at play here is a technique for allowing non-generic code to call into generic code.  It’s a little hard to see here because the return type is still generic, but notice how the &lt;code class=&quot;highlighter-rouge&quot;&gt;TRequest&lt;/code&gt; goes away when casting &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerWrapperImpl&amp;lt;TRequest,TResponse&amp;gt;&lt;/code&gt; to &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerWrapper&amp;lt;TResponse&amp;gt;&lt;/code&gt;.&lt;/p&gt;

&lt;p&gt;Lets take a look inside:&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt; 
 &lt;span class=&quot;k&quot;&gt;internal&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;abstract&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;RequestHandlerWrapper&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;RequestHandlerBase&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;abstract&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;CancellationToken&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;ServiceFactory&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;serviceFactory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
 
 &lt;span class=&quot;k&quot;&gt;internal&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;RequestHandlerWrapperImpl&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;RequestHandlerWrapper&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;where&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;IRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
         &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;override&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;CancellationToken&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;ServiceFactory&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;serviceFactory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Handler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;GetHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IRequestHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&amp;gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;serviceFactory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;).&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;((&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;

            &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;serviceFactory&lt;/span&gt;
                &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;GetInstances&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IPipelineBehavior&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&amp;gt;()&lt;/span&gt;
                &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Reverse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
                &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Aggregate&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;((&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;RequestHandlerDelegate&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Handler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;next&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;pipeline&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;pipeline&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;((&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;next&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;))();&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;Cool. So &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerWrapperImpl&amp;lt;TRequest, TResponse&amp;gt;&lt;/code&gt; implements the abstract &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerWrapper&amp;lt;TResponse&amp;gt;&lt;/code&gt;.  So we have the generic implementation extending the non-generic (with respect to TRequest).  Ultimately, &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerWrapper&amp;lt;TResponse&amp;gt;&lt;/code&gt; is providing a single non-generic handler interface that we can use to make calls into all the generic implementations for each request type.  Let’s see how the generic version accomplishes this:&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt; &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;override&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;CancellationToken&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;ServiceFactory&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;serviceFactory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Handler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;GetHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IRequestHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&amp;gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;serviceFactory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;).&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;((&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;

            &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;serviceFactory&lt;/span&gt;
                &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;GetInstances&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IPipelineBehavior&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&amp;gt;()&lt;/span&gt;
                &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Reverse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
                &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Aggregate&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;((&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;RequestHandlerDelegate&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Handler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;next&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;pipeline&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;pipeline&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;((&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;next&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;))();&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;MediatR has some cool features around pipelines, but a basic mediator doesn’t need any of that.  Let’s focus on how the &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerWrapperImpl&amp;lt;TRequest, TResponse&amp;gt;&lt;/code&gt; does it’s job of calling our &lt;code class=&quot;highlighter-rouge&quot;&gt;CreateTicketHandler&lt;/code&gt; with this line:&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Handler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;GetHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IRequestHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&amp;gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;serviceFactory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;).&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;((&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;

&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;Let’s break this down&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;First we call &lt;code class=&quot;highlighter-rouge&quot;&gt;GetHandler()&lt;/code&gt; on our base &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerBase&lt;/code&gt; class.  This should return our actual handler (&lt;code class=&quot;highlighter-rouge&quot;&gt;CreateTicketHandler&lt;/code&gt;).  We’ll take a look inside a little later&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;n&quot;&gt;GetHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IRequestHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&amp;gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;serviceFactory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;Then we call the &lt;code class=&quot;highlighter-rouge&quot;&gt;.Handle()&lt;/code&gt; method on the handler (&lt;code class=&quot;highlighter-rouge&quot;&gt;CreateTicketHandler&lt;/code&gt;).  We must cast the &lt;code class=&quot;highlighter-rouge&quot;&gt;IRequest&amp;lt;TResponse&amp;gt;&lt;/code&gt; to &lt;code class=&quot;highlighter-rouge&quot;&gt;TRequest&lt;/code&gt; to complete the bridge from the non-generic to generic.&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;((&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TRequest&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;With our command it would look like this&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;c1&quot;&gt;//request is an IRequest&amp;lt;CreateTicketResponse&amp;gt; from the non-generic&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;((&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CreateTicketCommand&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;request&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;Now instead of immediately running the &lt;code class=&quot;highlighter-rouge&quot;&gt;Handle()&lt;/code&gt; method above, we’re using a lambda to create Task that we can pass around and call later&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TResponse&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Handler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; 
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;At this point awaiting the Handler would wrap up our dispatch to &lt;code class=&quot;highlighter-rouge&quot;&gt;CreateTicketHandler&lt;/code&gt;.  Let’s back up one step and see how the instantiation of our handler with Dependency Injection went down in &lt;code class=&quot;highlighter-rouge&quot;&gt;RequestHandlerBase&lt;/code&gt;.&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt; &lt;span class=&quot;k&quot;&gt;protected&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;static&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;THandler&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;GetHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;THandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;ServiceFactory&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;factory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
 &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
     &lt;span class=&quot;n&quot;&gt;THandler&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;handler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
     &lt;span class=&quot;k&quot;&gt;try&lt;/span&gt;
     &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;handler&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;factory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;GetInstance&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;THandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;();&lt;/span&gt;
     &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;Interesting, I really expected more code.  Let’s take a look at &lt;code class=&quot;highlighter-rouge&quot;&gt;ServiceFactory&lt;/code&gt; to see what’s up.&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;delegate&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;object&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;ServiceFactory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Type&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;serviceType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;static&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;ServiceFactoryExtensions&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;static&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;T&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;GetInstance&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;T&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;this&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ServiceFactory&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;factory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;T&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;factory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;T&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;));&lt;/span&gt;

    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;static&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;IEnumerable&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;T&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;GetInstances&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;T&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;this&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ServiceFactory&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;factory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
            &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IEnumerable&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;T&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;)&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;factory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IEnumerable&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;T&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;));&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;&lt;strong&gt;Mind Blown!&lt;/strong&gt; &lt;code class=&quot;highlighter-rouge&quot;&gt;ServiceFactory&lt;/code&gt; is just a delegate.  As a bonus the method &lt;code class=&quot;highlighter-rouge&quot;&gt;GetInstance&amp;lt;THandler&amp;gt;&lt;/code&gt; is an extension method on the delegate.  That’s right &lt;mark&gt;C# supports extension methods on delegates&lt;/mark&gt;.  Essentially, &lt;code class=&quot;highlighter-rouge&quot;&gt;ServiceFactory&lt;/code&gt; is a single method wrapper around our Dependency Injection container.  The only burden &lt;code class=&quot;highlighter-rouge&quot;&gt;ServiceFactory&lt;/code&gt; puts on the underlying container is to have a method that takes in a &lt;code class=&quot;highlighter-rouge&quot;&gt;Type&lt;/code&gt; parameter and returns an instance of that type.  Using a couple of extension methods we overlay a nicer generic interface &lt;code class=&quot;highlighter-rouge&quot;&gt;T GetInstance&amp;lt;T&amp;gt;&lt;/code&gt; and &lt;code class=&quot;highlighter-rouge&quot;&gt;IEnumerable&amp;lt;T&amp;gt; GetInstances&amp;lt;T&amp;gt;&lt;/code&gt;.  You don’t see this kind of expressiveness in strongly-typed languages every day.&lt;/p&gt;

&lt;p&gt;&lt;mark&gt;MediatR's support for all the different dependency injection frameworks boils down to a simple delegate&lt;/mark&gt;.  Ironically, if you look into one of the Dependency Injection integrations like &lt;a href=&quot;https://github.com/jbogard/MediatR.Extensions.Microsoft.DependencyInjection/blob/master/src/MediatR.Extensions.Microsoft.DependencyInjection/Registration/ServiceRegistrar.cs&quot;&gt;MediatR.Extensions.Microsoft.DependencyInjection&lt;/a&gt;, it has about as much code for registering all the bells and whistles for handlers as the core of MediatR itself.&lt;/p&gt;</content><author><name>camron</name></author><category term="featured" /><category term="mediatR" /><category term="tutorial" /><summary type="html">It can be intimidating and time consuming to explore a mature open source project. Often an attempt to find inspiration results in a surface level understanding of a few components with no real insight into the magic. In this series I hope to find projects of just the right size and complexity to “get in there” and learn something valuable. Let’s start by taking a look at MediatR.</summary><media:thumbnail xmlns:media="http://search.yahoo.com/mrss/" url="https://cfrenzel.com/assets/images/mediatr.jpeg" /></entry><entry><title type="html">Simple Domain Events with EFCore and MediatR</title><link href="https://cfrenzel.com/domain-events-efcore-mediatr/" rel="alternate" type="text/html" title="Simple Domain Events with EFCore and MediatR" /><published>2020-01-03T00:00:00-05:00</published><updated>2020-01-03T00:00:00-05:00</updated><id>https://cfrenzel.com/domain-events-efcore-mediatr</id><content type="html" xml:base="https://cfrenzel.com/domain-events-efcore-mediatr/">&lt;p&gt;This post relates to the &lt;strong&gt;Domain Driven Design (DDD)&lt;/strong&gt; concept of &lt;strong&gt;Domain Events&lt;/strong&gt;.  These events originate in the Domain Model and are broadcast within a Bounded Context.  These are not events used directly for integration.  For the purpose of this implementation I want to frame things as EFCore entities publishing events that can be handled locally by one or more subscribers within a Unit Of Work.  For more information about what Domain Events are/aren’t and what they can be used for, check out &lt;a href=&quot;https://www.amazon.com/exec/obidos/ASIN/0321125215/domainlanguag-20&quot;&gt;Domain Driven Design&lt;/a&gt; by Eric Evans and &lt;a href=&quot;https://www.oreilly.com/library/view/implementing-domain-driven-design/9780133039900/&quot;&gt;Implementing Domain Driven Design&lt;/a&gt; by Vaughn Vernon.&lt;/p&gt;

&lt;p&gt;Beyond the initial difficulty of understanding what Domain Events are, lies figuring out a way to implement the things.  How the heck can you cleanly publish an event from an Entity?  How would you wire up listeners, and where in the architecture would the listeners live?  Our entities are often in a core assembly that doesn’t have any dependencies. There is no concept of a UnitOfWork/Transaction at this level, and they sure as heck don’t have access to anything interesting like databases or an Application Layer where you might normally think about hydrating other entities and handling events.&lt;/p&gt;

&lt;p&gt;This post describes a method to allow EFCore entities to publish Domain Events.  I’ve seen this technique used a handful of times, but to make this implementation a little more interesting Domain Events will be published as &lt;a href=&quot;https://github.com/jbogard/MediatR&quot;&gt;MediatR&lt;/a&gt; notifications that can be handled in the Application Layer.  In addition, this must be done without the entities taking on any external dependencies.  Specifically the entities won’t have a dependency on MediatR.&lt;/p&gt;

&lt;p&gt;Sound good? Let’s get started!&lt;/p&gt;

&lt;h4&gt;The Entity Side&lt;/h4&gt;

&lt;p&gt;The entity needs to call “Publish” on something.  One of the simplest implementations from the entity’s perspective is just to have the entity inherit from a base class that contains the publish logic.  In this implementation the entity won’t actually do the event dispatching, it will just hold a collection of events that a dispatcher will later examine.&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;First let’s define an interface for the Entity&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System.Collections.Concurrent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;namespace&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;DomainEventsMediatR.Domain&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;interface&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;IEntity&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;IProducerConsumerCollection&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IDomainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;DomainEvents&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

 &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;interface&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;IDomainEvent&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;Now a base class implementation for our EFCore entities marking the DomainEvents as &lt;code&gt;[NotMapped]&lt;/code&gt; to let EFCore know that they are not to be persisted to the db.&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;alert alert-primary&quot;&gt;
 We also add a helper for entities to initialize there own Id's.  It can be very useful and efficient for entities to have their Id's generated locally &quot;on or before instantiation&quot; rather than &quot;on save&quot; or in the database.  This allows transient entities to reference eachother by Id, to store Id's in Domain Events, and generally to use Id's in all kinds of eventual consistency scenarios.  You can pass the entity itself in the domain event, but remember that it hasn't been persisted yet; so you can't trust the transient Id assigned by EFcore (a new Id will be assigned by the database when persisted).
&lt;/div&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System.Collections.Concurrent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System.ComponentModel.DataAnnotations.Schema&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;namespace&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;DomainEventsMediatR.Domain&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; 
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;abstract&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;Entity&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;IEntity&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;     
        &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;NotMapped&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;readonly&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ConcurrentQueue&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IDomainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_domainEvents&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ConcurrentQueue&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IDomainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;();&lt;/span&gt;

        &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;NotMapped&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;IProducerConsumerCollection&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IDomainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;DomainEvents&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_domainEvents&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

        &lt;span class=&quot;k&quot;&gt;protected&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;PublishEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IDomainEvent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;@event&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;_domainEvents&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Enqueue&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;@event&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

        &lt;span class=&quot;k&quot;&gt;protected&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Guid&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;NewIdGuid&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;MassTransit&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;NewId&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;NextGuid&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;();&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;
&lt;ul&gt;
  &lt;li&gt;Now a Domain Event: &lt;code&gt;BacklogItemCommitted&lt;/code&gt; and an entity: &lt;code&gt;BacklogItem&lt;/code&gt; that publishes the event when it is commited to a &lt;code&gt;Sprint&lt;/code&gt;&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;k&quot;&gt;namespace&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;DomainEventsMediatR.Domain&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;BacklogItemCommitted&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;IDomainEvent&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Guid&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;BacklogItemId&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Guid&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;SprintId&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;set&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;DateTime&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;CreatedAtUtc&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

        &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;BacklogItemCommitted&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;BacklogItemCommitted&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;BacklogItem&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;b&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Sprint&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;s&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;BacklogItemId&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;b&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Id&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CreatedAtUtc&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;b&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CreatedAtUtc&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;SprintId&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;s&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Id&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;    
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;


&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System.ComponentModel.DataAnnotations&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;namespace&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;DomainEventsMediatR.Domain&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;BacklogItem&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Entity&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Guid&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Id&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;set&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

        &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;MaxLength&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;m&quot;&gt;255&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)]&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;string&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Description&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;set&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;virtual&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Sprint&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Sprint&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;set&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;DateTime&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;CreatedAtUtc&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;set&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;DateTime&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;UtcNow&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

        &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;BacklogItem&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;BacklogItem&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;string&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;desc&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Id&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;NewIdGuid&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;();&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Description&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;desc&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
    
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;void&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;CommitTo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Sprint&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;s&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Sprint&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;s&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;PublishEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;new&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;BacklogItemCommitted&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;this&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;s&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;));&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;
&lt;ul&gt;
  &lt;li&gt;The real magic with this technique is how the Domain Events are dispatched.  Currently they’re just sitting in the Entity.  We’ll use some hooks in our DbContext to dispatch them, but first let’s define an interface for the dispatcher&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System.Threading.Tasks&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;namespace&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;DomainEventsMediatR.Domain&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;interface&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;IDomainEventDispatcher&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Dispatch&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IDomainEvent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;devent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;Now we can configure the dispatcher to be injected into our DbContext constructor&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt; &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;ApplicationDbContext&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;DbContext&lt;/span&gt;
 &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;readonly&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;IDomainEventDispatcher&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_dispatcher&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;ApplicationDbContext&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;DbContextOptions&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;ApplicationDbContext&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;options&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;IDomainEventDispatcher&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;dispatcher&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;base&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;options&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;_dispatcher&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;dispatcher&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;We can hook into EFCore and dispatch Domain Events before entities are persisted by overriding &lt;code&gt;SaveChanges&lt;/code&gt;&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;override&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;SaveChanges&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;nf&quot;&gt;_preSaveChanges&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;().&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;GetAwaiter&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;().&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;GetResult&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;();&lt;/span&gt;
    &lt;span class=&quot;kt&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;res&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;base&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SaveChanges&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;();&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;res&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;override&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;async&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;int&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;SaveChangesAsync&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CancellationToken&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;default&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;))&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;await&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;_preSaveChanges&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;();&lt;/span&gt;
    &lt;span class=&quot;kt&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;res&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;await&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;base&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SaveChangesAsync&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;res&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;async&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;_preSaveChanges&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;await&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;_dispatchDomainEvents&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;();&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;async&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;_dispatchDomainEvents&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;kt&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;domainEventEntities&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ChangeTracker&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Entries&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IEntity&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;()&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Select&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;po&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;po&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Entity&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Where&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;po&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;po&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;DomainEvents&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Any&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;())&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;ToArray&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;();&lt;/span&gt;

    &lt;span class=&quot;k&quot;&gt;foreach&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;kt&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;entity&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;in&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;domainEventEntities&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;n&quot;&gt;IDomainEvent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;dev&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;while&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;entity&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;DomainEvents&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;TryTake&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;out&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;dev&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;))&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;await&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_dispatcher&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Dispatch&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;dev&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;h4&gt;The Dispatcher&lt;/h4&gt;
&lt;p&gt;We need an implementation of &lt;code&gt;IDomainEventDispatcher&lt;/code&gt; that will publish the Domain Event as a MediatR notification.  We’ll implement this in our Application Layer.  We do have to deal with the small issue of our Domain Event not being a valid MediatR &lt;code&gt;INotification&lt;/code&gt;.  We’ll overcome this by creating a generic &lt;code&gt;INotification&lt;/code&gt; to wrap our Domain Event.&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;Create a custom generic &lt;code&gt;INotification&lt;/code&gt;.&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;MediatR&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;DomainEventsMediatR.Domain&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;namespace&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;DomainEventsMediatR.Application&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;DomainEventNotification&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TDomainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;INotification&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;where&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;TDomainEvent&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;IDomainEvent&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;TDomainEvent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;DomainEvent&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;get&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;DomainEventNotification&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;TDomainEvent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;domainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;DomainEvent&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;domainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;Create a Dispatcher that wraps Domain Events in MediatR notificatoins and publishes them&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System.Threading.Tasks&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;Microsoft.Extensions.Logging&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;MediatR&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;DomainEventsMediatR.Domain&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;namespace&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;DomainEventsMediatR.Application&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;MediatrDomainEventDispatcher&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;IDomainEventDispatcher&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;readonly&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;IMediator&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_mediator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;readonly&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ILogger&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;MediatrDomainEventDispatcher&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_log&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;MediatrDomainEventDispatcher&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IMediator&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;mediator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ILogger&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;MediatrDomainEventDispatcher&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;log&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;_mediator&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;mediator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;_log&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;log&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;async&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Dispatch&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IDomainEvent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;devent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;

            &lt;span class=&quot;kt&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;domainEventNotification&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;_createDomainEventNotification&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;devent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
            &lt;span class=&quot;n&quot;&gt;_log&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;LogDebug&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Dispatching Domain Event as MediatR notification.  EventType: {eventType}&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;devent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;GetType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;());&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;await&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_mediator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Publish&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;domainEventNotification&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
       
        &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;INotification&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;_createDomainEventNotification&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IDomainEvent&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;domainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;kt&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;genericDispatcherType&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;DomainEventNotification&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&amp;gt;).&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;MakeGenericType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;domainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;GetType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;());&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;INotification&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Activator&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;CreateInstance&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;genericDispatcherType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;domainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;

        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;Create a handler for the &lt;code&gt;BacklogItemCommitted&lt;/code&gt; Domain Event&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System.Threading&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;System.Threading.Tasks&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;Microsoft.Extensions.Logging&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;MediatR&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;DomainEventsMediatR.Domain&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;using&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;DomainEventsMediatR.Persistence&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;

&lt;span class=&quot;k&quot;&gt;namespace&lt;/span&gt; &lt;span class=&quot;nn&quot;&gt;DomainEventsMediatR.Application&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;OnBacklogItemCommitted&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
        &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;class&lt;/span&gt; &lt;span class=&quot;nc&quot;&gt;Handler&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;INotificationHandler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;DomainEventNotification&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;BacklogItemCommitted&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&amp;gt;&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;readonly&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ApplicationDbContext&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_db&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
            &lt;span class=&quot;k&quot;&gt;private&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;readonly&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;ILogger&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Handler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_log&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
        
            &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Handler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;ApplicationDbContext&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;db&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;  &lt;span class=&quot;n&quot;&gt;ILogger&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Handler&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;log&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
            &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;_db&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;db&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
                &lt;span class=&quot;n&quot;&gt;_log&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;log&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
            &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

            &lt;span class=&quot;k&quot;&gt;public&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;Handle&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;DomainEventNotification&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;BacklogItemCommitted&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;notification&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;CancellationToken&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;cancellationToken&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
            &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
                &lt;span class=&quot;kt&quot;&gt;var&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;domainEvent&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;notification&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;DomainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
                &lt;span class=&quot;k&quot;&gt;try&lt;/span&gt;
                &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
                    &lt;span class=&quot;n&quot;&gt;_log&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;LogDebug&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Handling Domain Event. BacklogItemId: {itemId}  Type: {type}&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;domainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;BacklogItemId&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;notification&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;GetType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;());&lt;/span&gt;
                    &lt;span class=&quot;c1&quot;&gt;//from here you could &lt;/span&gt;
                    &lt;span class=&quot;c1&quot;&gt;// - create/modify entities within the same transaction as the backlogItem commit&lt;/span&gt;
                    &lt;span class=&quot;c1&quot;&gt;// - trigger the publishing of an integration event on a servicebus (don't write it directly though, you need an outbox scoped to this transaction)&lt;/span&gt;
                                      
                    &lt;span class=&quot;c1&quot;&gt;//Remember NOT to call SaveChanges on dbcontext if making db changes when handling DomainEvents&lt;/span&gt;
                    &lt;span class=&quot;k&quot;&gt;return&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Task&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;CompletedTask&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
                &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
                &lt;span class=&quot;k&quot;&gt;catch&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Exception&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;exc&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
                &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
                    &lt;span class=&quot;n&quot;&gt;_log&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;LogError&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;exc&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;Error handling domain event {domainEvent}&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;domainEvent&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;GetType&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;());&lt;/span&gt;
                    &lt;span class=&quot;k&quot;&gt;throw&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
                &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
            &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;

    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;Now we just need to configure dependency injection in our application and we’re done&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;     &lt;span class=&quot;n&quot;&gt;services&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;AddTransient&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;lt;&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;IDomainEventDispatcher&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;MediatrDomainEventDispatcher&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;&amp;gt;();&lt;/span&gt;
     &lt;span class=&quot;n&quot;&gt;services&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;AddMediatR&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;typeof&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;MediatrDomainEventDispatcher&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;).&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;GetTypeInfo&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;().&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Assembly&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;You can find the full source code for this post at &lt;a href=&quot;https://github.com/cfrenzel/DomainEventsWithMediatR&quot;&gt;https://github.com/cfrenzel/DomainEventsWithMediatR&lt;/a&gt;&lt;/p&gt;</content><author><name>camron</name></author><category term="dotnet" /><category term="efcore" /><category term="ddd" /><category term="mediatR" /><summary type="html">This post relates to the Domain Driven Design (DDD) concept of Domain Events. These events originate in the Domain Model and are broadcast within a Bounded Context. These are not events used directly for integration. For the purpose of this implementation I want to frame things as EFCore entities publishing events that can be handled locally by one or more subscribers within a Unit Of Work. For more information about what Domain Events are/aren’t and what they can be used for, check out Domain Driven Design by Eric Evans and Implementing Domain Driven Design by Vaughn Vernon.</summary><media:thumbnail xmlns:media="http://search.yahoo.com/mrss/" url="https://cfrenzel.com/assets/images/book-Evans_2004_ddd.jpg" /></entry><entry><title type="html">Quickly Create Your Own .NET Code Templates and Use Them From Anywhere</title><link href="https://cfrenzel.com/dotnet-new-templating-nuget/" rel="alternate" type="text/html" title="Quickly Create Your Own .NET Code Templates and Use Them From Anywhere" /><published>2019-12-20T00:00:00-05:00</published><updated>2019-12-20T00:00:00-05:00</updated><id>https://cfrenzel.com/dotnet-new-templating-nuget</id><content type="html" xml:base="https://cfrenzel.com/dotnet-new-templating-nuget/">&lt;p&gt;Whether you need to throw together a quick console app or scaffold an enterprise solution, it can be a real time suck just creating, naming and referencing projects.  Setting up boilerplate logging, dependency injection, data access, messaging, gulp and other tools can send you hunting through previous work to copy and paste code.  Let’s put an end to all that once and for all with less than an hour of work using &lt;code&gt;dotnet new&lt;/code&gt; templating! The advantages of this approach include:&lt;/p&gt;

&lt;div class=&quot;highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;- Use a tool that's already on any development machine       
- No new templating language to learn
- Use runnable Solution/Project/Files as templates
- Bundle many templates into a single distributable package
- Access templates from any machine with a single command
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;h4&gt;Let's get started:&lt;/h4&gt;

&lt;p&gt;Our goal is to be able to easily create and distribute custom templates to any machine; so let’s first take a look at what templates already exist on our machine:&lt;/p&gt;

&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;gp&quot;&gt;&amp;gt;&lt;/span&gt; dotnet new &lt;span class=&quot;nt&quot;&gt;-l&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;
&lt;pre&gt;
Templates                                         Short Name               Language          Tags
----------------------------------------------------------------------------------------------------------------------------------
Console Application                               console                  [C#], F#, VB      Common/Console
Class library                                     classlib                 [C#], F#, VB      Common/Library
&lt;/pre&gt;

&lt;p&gt;You should see a list of templates longer but similar to above.  Our custom templates will show up in this list when we’re done.  To create a new project from the template named &lt;code&gt;console&lt;/code&gt; in the list above we can type:&lt;/p&gt;

&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;gp&quot;&gt;&amp;gt;&lt;/span&gt;  dotnet new console &lt;span class=&quot;nt&quot;&gt;-n&lt;/span&gt; SampleFromTemplate
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;
&lt;p&gt;This will create a new folder with a console app named &lt;code&gt;SampleFromTemplate&lt;/code&gt;.  It’s ready to go with nuget packages restored and the namespaces set to &lt;em&gt;SampleFromTemplate&lt;/em&gt;.&lt;/p&gt;
&lt;pre&gt;
SampleFromTemplate
    └─── SampleFromTemplate.csproj
    └─── Program.cs
    └─── /obj
&lt;/pre&gt;

&lt;p&gt;To begin creating custom templates with &lt;code&gt;dotnet new&lt;/code&gt; simply create a normal project or solution (or just one or more files) that represents your boilerplate code for a given scenario.  That’s almost all there is to it.  Adding a configuration file to setup some metadata and behavior will result in a resuable template.  The template folder structure for a simple console app project will look something like this:&lt;/p&gt;

&lt;pre&gt;
└───mycustomtemplate
    └─── Templating.ConsoleApp.csproj
    └─── Program.cs
    └─── /.template_config
        └───  template.json
&lt;/pre&gt;

&lt;ul&gt;
  &lt;li&gt;Start with any existing project and from the project root folder&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;gp&quot;&gt;&amp;gt;&lt;/span&gt;  &lt;span class=&quot;nb&quot;&gt;mkdir&lt;/span&gt; .template_config
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;
&lt;div class=&quot;alert alert-warning&quot;&gt;
 You have control over whether the generated output of your template is placed in a new folder or just dumped in the output location.  If you want everything inside a folder then include the folder at the top level of the template beside the &lt;code&gt;.template_config&lt;/code&gt; folder.  Otherwise you can leave it up to the user to specify on the command line using the &lt;code&gt;-o&lt;/code&gt; option.  
&lt;/div&gt;
&lt;div class=&quot;alert alert-warning&quot;&gt;
If you want to create empty folders inside your template such as &lt;code&gt;/src&lt;/code&gt; &lt;code&gt;/test&lt;/code&gt; &lt;code&gt;/doc&lt;/code&gt; &lt;code&gt;/build&lt;/code&gt; &lt;code&gt;/migrations&lt;/code&gt;.  For now you will need to place a file named &lt;code&gt;-.-&lt;/code&gt; inside the folder otherwise the empty folder will be ignored in the output
&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;Add a &lt;code&gt;template.json&lt;/code&gt; to the &lt;code&gt;.template_config&lt;/code&gt; folder&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-javascript highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
  &lt;span class=&quot;s2&quot;&gt;&quot;$schema&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;http://json.schemastore.org/template&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
  &lt;span class=&quot;s2&quot;&gt;&quot;author&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;Camron Frenzel&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
  &lt;span class=&quot;s2&quot;&gt;&quot;classifications&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;cfrenzel&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;core&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;console&quot;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;],&lt;/span&gt;
  &lt;span class=&quot;s2&quot;&gt;&quot;tags&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
    &lt;span class=&quot;s2&quot;&gt;&quot;language&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;C#&quot;&lt;/span&gt;
  &lt;span class=&quot;p&quot;&gt;},&lt;/span&gt;
  &lt;span class=&quot;s2&quot;&gt;&quot;identity&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;demo.console&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
  &lt;span class=&quot;s2&quot;&gt;&quot;name&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;demo.console_2.2&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
  &lt;span class=&quot;s2&quot;&gt;&quot;shortName&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;dm-console-2.2&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
  &lt;span class=&quot;s2&quot;&gt;&quot;sourceName&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;Templating&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt;
  &lt;span class=&quot;s2&quot;&gt;&quot;sources&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
      &lt;span class=&quot;s2&quot;&gt;&quot;modifiers&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;
        &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;exclude&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;:&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;.vs/**&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;.template_config/**&quot;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
      &lt;span class=&quot;p&quot;&gt;]&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
  &lt;span class=&quot;p&quot;&gt;],&lt;/span&gt;
&lt;span class=&quot;p&quot;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;&lt;code&gt;identity&lt;/code&gt; a unique name for the template&lt;/li&gt;
  &lt;li&gt;&lt;code&gt;name&lt;/code&gt; for display purposes&lt;/li&gt;
  &lt;li&gt;&lt;code&gt;shortName&lt;/code&gt; what users will type to specify your template&lt;/li&gt;
  &lt;li&gt;&lt;code&gt;sources -&amp;gt; exclude:&lt;/code&gt; This is a little trick to keep some unwanted files out of the template&lt;/li&gt;
  &lt;li&gt;
    &lt;p&gt;&lt;code&gt;sourceName&lt;/code&gt; the name in the source tree to replace with the user specified name (using &lt;code&gt;-n&lt;/code&gt; or &lt;code&gt;--name&lt;/code&gt;).&lt;/p&gt;

    &lt;p&gt;&lt;strong&gt;&lt;code&gt;sourceName&lt;/code&gt; is important!&lt;/strong&gt;.  &lt;code&gt;dotnet new&lt;/code&gt; will replace all the folders/files/namespaces/etc.. containing this name with whatever the user passes in on the command line.  For example: If I’m using a convention such as&lt;/p&gt;
    &lt;pre&gt;
  └─── Templating.sln
  └─── /src
      └─── /Templating.ConsoleApp
          └─── Templating.ConsoleApp.csproj
      └─── /Templating.Domain
          └─── Templating.Domain.csproj
      └─── /Templating.Application
          └─── Templating.Application.csproj
  &lt;/pre&gt;

    &lt;p&gt;Then passing in &lt;code&gt;-n Demo&lt;/code&gt;  will produce:&lt;/p&gt;
    &lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;gp&quot;&gt;  &amp;gt;&lt;/span&gt;  dotnet new demo.console_2.2 &lt;span class=&quot;nt&quot;&gt;-n&lt;/span&gt; Demo
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;    &lt;/div&gt;
    &lt;pre&gt;
  └─── Demo.sln
  └─── /src
      └─── /Demo.ConsoleApp
          └─── Demo.ConsoleApp.csproj
      └─── /Demo.Domain
          └─── Demo.Domain.csproj
      └─── /Demo.Application
          └─── Demo.Application.csproj
    
   namespaces: Templating.ConsoleApp -&amp;gt; Demo.ConsoleApp
&lt;/pre&gt;
  &lt;/li&gt;
  &lt;li&gt;At this point you should be comfortable with these concepts
    &lt;ul&gt;
      &lt;li&gt;a template is a normal solution/project/file&lt;/li&gt;
      &lt;li&gt;add a &lt;code&gt;.template_config&lt;/code&gt; folder with a &lt;code&gt;template.config&lt;/code&gt; file in it to configure a template&lt;/li&gt;
      &lt;li&gt;the user will pass in a –name &lt;em&gt;MyApp&lt;/em&gt; to the template that will replace the configured &lt;code&gt;sourceName&lt;/code&gt; text in all folders/solutions/projects/namespaces&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;alert alert-primary&quot;&gt;
&lt;strong&gt;Tip!&lt;/strong&gt; To have nuget restore automatically - add this to your template.config
&lt;pre&gt;
&quot;symbols&quot;: {
    &quot;skipRestore&quot;: {
      &quot;type&quot;: &quot;parameter&quot;,
      &quot;datatype&quot;: &quot;bool&quot;,
      &quot;description&quot;: &quot;If specified, skips the automatic restore of the project on create.&quot;,
      &quot;defaultValue&quot;: &quot;false&quot;
    }
  },
  &quot;postActions&quot;: [
    {
      &quot;condition&quot;: &quot;(!skipRestore)&quot;,
      &quot;description&quot;: &quot;Restore NuGet packages required by this project.&quot;,
      &quot;manualInstructions&quot;: [
        { &quot;text&quot;: &quot;Run 'dotnet restore'&quot; }
      ],
      &quot;actionId&quot;: &quot;210D431B-A78B-4D2F-B762-4ED3E3EA9025&quot;,
      &quot;continueOnError&quot;: true
    }
  ]
  &lt;/pre&gt;
&lt;/div&gt;

&lt;div class=&quot;alert alert-danger&quot;&gt;
&lt;strong&gt;Issue!&lt;/strong&gt;  If your template creates one or more projects, often you would like the generated projects to be automatically added to an existing solution.  This is supported, but I haven't had any luck with it.  The essence of the problem seems to be a bug rendering the output project path/name.  

&lt;pre&gt;
  &quot;primaryOutputs&quot;: [
    { &quot;path&quot;: &quot;SolutionName.ConsoleApp/SolutionName.ConsoleApp.csproj&quot; }
  ],

  &quot;postActions&quot;: [
    {
      &quot;description&quot;: &quot;Add project to solution&quot;,
      &quot;manualInstructions&quot;: [],
      &quot;primaryOutputIndexes&quot;: &quot;0&quot;,
      &quot;actionId&quot;: &quot;D396686C-DE0E-4DE6-906D-291CD29FC5DE&quot;,
      &quot;continueOnError&quot;: true
    }
  ]
&lt;/pre&gt; 
  &lt;a href=&quot;https://github.com/dotnet/templating/issues/1489&quot;&gt;https://github.com/dotnet/templating/issues/1489&lt;/a&gt;
&lt;/div&gt;

&lt;p&gt;If you haven’t created your own template at this point you can follow along by downloading a console app template with logging/DI/configuration &lt;a href=&quot;https://github.com/cfrenzel/dotnet-new-templates-2.2/tree/master/templates/ConsoleApp&quot;&gt;here&lt;/a&gt;&lt;/p&gt;

&lt;h4&gt;Installing a template&lt;/h4&gt;

&lt;p&gt;We could install our template locally from the template root folder.&lt;/p&gt;

&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;go&quot;&gt;dotnet new -i .
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;List the installed templates and you should see your template listed&lt;/p&gt;
&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;go&quot;&gt;dotnet new -l
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;You can use it by passing in it’s &lt;code&gt;shortName&lt;/code&gt; and provide a name&lt;/p&gt;
&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;gp&quot;&gt;    &amp;gt;&lt;/span&gt;  dotnet new &lt;span class=&quot;o&quot;&gt;{&lt;/span&gt;shortname&lt;span class=&quot;o&quot;&gt;}&lt;/span&gt; &lt;span class=&quot;nt&quot;&gt;-n&lt;/span&gt; DemoApp
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;To remove your template&lt;/p&gt;
&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;go&quot;&gt;dotnet new -u
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;
&lt;p&gt;You should see your template along with an &lt;code&gt;Uninstall command:&lt;/code&gt;.  This command will come in handy as things can get confusing when managing multiple versions of your templates and installing them from different sources.&lt;/p&gt;

&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;go&quot;&gt; dotnet new -u C:\temptemplate\temptemplate
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;Not bad, but the workflow leaves a lot to be desired.  It would be a pain to manage even a modest number of templates using this method.&lt;/p&gt;

&lt;h4&gt;Packaging templates&lt;/h4&gt;

&lt;p&gt;The &lt;code&gt;dotnet new&lt;/code&gt; templating tool supports installing templates from nuget packages locally or in remote repositories.  Multiple templates can be included in a single package, which allows adding and removing collections of templates from the internet with a single command.&lt;/p&gt;

&lt;p&gt;Packaging templates took some tinkering for me; so let’s get straight to what works by creating a special project that will help us get all of our templates into a single package.  The structure of our multi-template solution will look like this:&lt;/p&gt;

&lt;pre&gt;
 └─── /my-dotnet-templates   
      └─── my-dotnet-templates.sln
      └─── /templates
           └─── Directory.Build.props //metadata for package
           └─── templates.csproj
           └─── /ConsoleApp //template 1
                └─── Templating.sln
                └─── /.template_config
                     └───template.json
                └─── /Templating.ConsoleApp
                     └─── Templating.ConsoleApp.csproj
           └─── /WebApp //template 2
                └─── Templating.sln
                └─── /.template_config
                     └───template.json
                └─── /Templating.WebbApp
                     └─── Templating.WebApp.csproj
           
&lt;/pre&gt;

&lt;p&gt;The idea is that you have a solution with a /templates folder and a special project: &lt;code&gt;template.csproj&lt;/code&gt; that will aid in building the multi-template package. Within the 
/templates folder you will have a folder for each template.  The folder for each template should contain everything you need to develop and test the template. You won’t be able to run the template from our special &lt;code&gt;templates.csproj&lt;/code&gt; so it’s nice to have a seperate solution for running/editing each template.&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;You can start by creating &lt;code&gt;templates.csproj&lt;/code&gt; as a console app.  Open the .csproj file and edit it to look like this:&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-xml highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;nt&quot;&gt;&amp;lt;Project&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;Sdk=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Microsoft.NET.Sdk&quot;&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&amp;gt;&lt;/span&gt;

  &lt;span class=&quot;nt&quot;&gt;&amp;lt;PropertyGroup&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;PackageType&amp;gt;&lt;/span&gt;Template&lt;span class=&quot;nt&quot;&gt;&amp;lt;/PackageType&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;TargetFramework&amp;gt;&lt;/span&gt;netcoreapp2.2&lt;span class=&quot;nt&quot;&gt;&amp;lt;/TargetFramework&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;PackageId&amp;gt;&lt;/span&gt;cfrenzel-dotnet-new-templates-2.2&lt;span class=&quot;nt&quot;&gt;&amp;lt;/PackageId&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;Title&amp;gt;&lt;/span&gt;cfrenzel dotnet-new-templates&lt;span class=&quot;nt&quot;&gt;&amp;lt;/Title&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;IncludeContentInPack&amp;gt;&lt;/span&gt;true&lt;span class=&quot;nt&quot;&gt;&amp;lt;/IncludeContentInPack&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;IncludeBuildOutput&amp;gt;&lt;/span&gt;false&lt;span class=&quot;nt&quot;&gt;&amp;lt;/IncludeBuildOutput&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;ContentTargetFolders&amp;gt;&lt;/span&gt;content&lt;span class=&quot;nt&quot;&gt;&amp;lt;/ContentTargetFolders&amp;gt;&lt;/span&gt;
  &lt;span class=&quot;nt&quot;&gt;&amp;lt;/PropertyGroup&amp;gt;&lt;/span&gt;

  &lt;span class=&quot;nt&quot;&gt;&amp;lt;ItemGroup&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;Content&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;Include=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;ConsoleApp\**&quot;&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;Exclude=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;ConsoleApp\SolutionName.sln;ConsoleApp\**\bin\**;ConsoleApp\**\obj\**;ConsoleApp\**\.vs\**&quot;&lt;/span&gt; &lt;span class=&quot;nt&quot;&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;Content&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;Include=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;EFCore.MigrationProjects\**&quot;&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;Exclude=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;EFCore.MigrationProjects\**\bin\**;EFCore.MigrationProjects\**\obj\**;EFCore.MigrationProjects\**\.vs\**&quot;&lt;/span&gt; &lt;span class=&quot;nt&quot;&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;Content&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;Include=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Solution\**&quot;&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;Exclude=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Solution\**\bin\**;Solution\**\obj\**;Solution\**\.vs\**&quot;&lt;/span&gt; &lt;span class=&quot;nt&quot;&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;Compile&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;Remove=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;**\*&quot;&lt;/span&gt; &lt;span class=&quot;nt&quot;&gt;/&amp;gt;&lt;/span&gt;
  &lt;span class=&quot;nt&quot;&gt;&amp;lt;/ItemGroup&amp;gt;&lt;/span&gt;

&lt;span class=&quot;nt&quot;&gt;&amp;lt;/Project&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;
&lt;ul&gt;
  &lt;li&gt;&lt;code class=&quot;highlighter-rouge&quot;&gt;&amp;lt;PackageType&amp;gt;Template&amp;lt;/PackageType&amp;gt;&lt;/code&gt; - set special package type for project&lt;/li&gt;
  &lt;li&gt;For each template in our package we are adding a &lt;code class=&quot;highlighter-rouge&quot;&gt;&amp;lt;Content&amp;gt;&lt;/code&gt; tag that specifies which files to include and exclude
    &lt;ul&gt;
      &lt;li&gt;&lt;code class=&quot;highlighter-rouge&quot;&gt;&amp;lt;Content Include=&quot;ConsoleApp\**&quot;&lt;/code&gt; - include everything from our /ConsoleApp folder&lt;/li&gt;
      &lt;li&gt;&lt;code class=&quot;highlighter-rouge&quot;&gt;Exclude=&quot;ConsoleApp\Templating.sln;ConsoleApp\**\bin\**;ConsoleApp\**\obj\**;ConsoleApp\**\.vs\**&quot; /&amp;gt;&lt;/code&gt; - exclude the solution file and bin/obj folders&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/li&gt;
  &lt;li&gt;
    &lt;p&gt;&lt;code class=&quot;highlighter-rouge&quot;&gt;&amp;lt;Compile Remove=&quot;**\*&quot; /&amp;gt;&lt;/code&gt; - we’re not interested in the output of the compiled project&lt;/p&gt;
  &lt;/li&gt;
  &lt;li&gt;We can specify metadata for the package in &lt;code&gt;Directory.Build.props&lt;/code&gt;&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-xml highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;nt&quot;&gt;&amp;lt;Project&amp;gt;&lt;/span&gt;
  &lt;span class=&quot;nt&quot;&gt;&amp;lt;PropertyGroup&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;Authors&amp;gt;&lt;/span&gt;Camron Frenzel&lt;span class=&quot;nt&quot;&gt;&amp;lt;/Authors&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;RepositoryUrl&amp;gt;&lt;/span&gt;https://github.com/cfrenzel/dotnet-new-templates-2.2.git&lt;span class=&quot;nt&quot;&gt;&amp;lt;/RepositoryUrl&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;PackageProjectUrl&amp;gt;&lt;/span&gt;https://github.com/cfrenzel/dotnet-new-templates-2.2&lt;span class=&quot;nt&quot;&gt;&amp;lt;/PackageProjectUrl&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;Description&amp;gt;&lt;/span&gt;dotnet new templates for core 2.2&lt;span class=&quot;nt&quot;&gt;&amp;lt;/Description&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;PackageTags&amp;gt;&lt;/span&gt;template dotnet console migration web&lt;span class=&quot;nt&quot;&gt;&amp;lt;/PackageTags&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;PackageLicense&amp;gt;&amp;lt;/PackageLicense&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;Version&amp;gt;&lt;/span&gt;1.0.0&lt;span class=&quot;nt&quot;&gt;&amp;lt;/Version&amp;gt;&lt;/span&gt;   
  &lt;span class=&quot;nt&quot;&gt;&amp;lt;/PropertyGroup&amp;gt;&lt;/span&gt;
&lt;span class=&quot;nt&quot;&gt;&amp;lt;/Project&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;Now we can create our nuget package using &lt;code&gt;templates.csproj&lt;/code&gt;&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;go&quot;&gt;dotnet pack .\templates\templates.csproj -o .\artifacts\ --no-build
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;And install all of our templates locally from our &lt;code&gt;.nupkg&lt;/code&gt; file&lt;/p&gt;

&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;go&quot;&gt;dotnet new -i .\artifacts\cfrenzel-dotnet-new-templates-2.2.1.0.0
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;Find the &lt;code&gt;Uninstall command:&lt;/code&gt; to remove&lt;/p&gt;
&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;go&quot;&gt;dotnet new -u
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;h4&gt;Publish package for access online&lt;/h4&gt;

&lt;p&gt;You can host your template .nupkg for free using my &lt;a href=&quot;https://www.myget.org/&quot;&gt;MyGet&lt;/a&gt; or make it official/perminent using &lt;a href=&quot;https://www.nuget.org/&quot;&gt;NuGet.org&lt;/a&gt;.  This can be as simple as typing&lt;/p&gt;

&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;go&quot;&gt;dotnet nuget push artifacts\**\*.nupkg -s &quot;https://www.myget.org/F/{youraccount}/api/v2/package&quot; -k {yourkey}
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;Then installing your templates from anywhere using&lt;/p&gt;

&lt;div class=&quot;language-console highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;go&quot;&gt;dotnet new --install {yourpackagename}  --nuget-source https://www.myget.org/F/{youraccount}/api/v3/index.json
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;
&lt;div class=&quot;alert alert-primary&quot;&gt;
  If you publish it to &lt;strong&gt;nuget.org&lt;/strong&gt; you don't even have to specify the package url!
  dotnet new --install {yourpackagename}
&lt;/div&gt;

&lt;p&gt;-Since we’re pretty much one configuration file away from free continuous build and deployment, let’s setup &lt;a href=&quot;https://www.appveyor.com/&quot;&gt;AppVeyor&lt;/a&gt; to build and publish our template package every time we commit a change to the source code.&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;Save you code to &lt;a href=&quot;https://github.com&quot;&gt;Github&lt;/a&gt; or wherever&lt;/li&gt;
  &lt;li&gt;Add an &lt;code&gt;appveyor.yml&lt;/code&gt; to build and publish template package to MyGet&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;version: '1.{build}'
image: Visual Studio 2019
environment:
  MyGetApiKey:
    secure: 56nW3KcP4naYX9mlsVEIKLj5xPdfmpt6lMALR6wQmorRQOaoUOtlwMZ2V0BtGTAM
  NugetApiKey:
    secure: /54XAunyBETRa1Fp/qSrwvebSnTAcHDO2OVZ+exMtQtOtrBzHKvp4RC1AB8RD2PQ
pull_requests:
  do_not_increment_build_number: true
branches:
  only:
  - master
nuget:
  disable_publish_on_pr: true
test: off
build_script:
  - dotnet restore 
  - dotnet pack .\templates\templates.csproj -o .\artifacts\ --no-build
deploy_script:
  - ps: dotnet nuget push artifacts\**\*.nupkg -s &quot;https://www.myget.org/F/cfrenzel-ci/api/v2/package&quot; -k $env:MyGetApiKey
 
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;
&lt;p&gt;After you link your AppVeyor project to your source repo, your template .nupkg will be updated in MyGet/Nuget every time you commit to master.&lt;/p&gt;

&lt;h4&gt;Final Thoughts&lt;/h4&gt;
&lt;p&gt;Though templating with &lt;code&gt;dotnet new&lt;/code&gt; has some more powerful features including:&lt;/p&gt;
&lt;ul&gt;
  &lt;li&gt;conditional logic&lt;/li&gt;
  &lt;li&gt;custom parameters&lt;/li&gt;
  &lt;li&gt;post actions&lt;/li&gt;
  &lt;li&gt;multi-language&lt;/li&gt;
  &lt;li&gt;&lt;a href=&quot;https://github.com/dotnet/templating/wiki/Reference-for-template.json&quot;&gt;see docs - template.json&lt;/a&gt;&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;I really appreciate the simplicity of the tool.  You simply use what you’re already doing to make doing what you’re already doing faster.  No need to learn a new complex template language.&lt;/p&gt;

&lt;p&gt;&lt;a href=&quot;https://github.com/cfrenzel/dotnet-new-templates-2.2&quot;&gt;full source code &lt;/a&gt; for this post.&lt;/p&gt;</content><author><name>camron</name></author><category term="featured" /><category term="dotnet" /><category term="automation" /><category term="nuget" /><category term="appveyor" /><summary type="html">Whether you need to throw together a quick console app or scaffold an enterprise solution, it can be a real time suck just creating, naming and referencing projects. Setting up boilerplate logging, dependency injection, data access, messaging, gulp and other tools can send you hunting through previous work to copy and paste code. Let’s put an end to all that once and for all with less than an hour of work using dotnet new templating! The advantages of this approach include:</summary><media:thumbnail xmlns:media="http://search.yahoo.com/mrss/" url="https://cfrenzel.com/assets/images/dotnet-new.png" /></entry><entry><title type="html">Publishing .NET Core NuGet Packages with Nuke and AppVeyor</title><link href="https://cfrenzel.com/publishing-nuget-nuke-appveyor/" rel="alternate" type="text/html" title="Publishing .NET Core NuGet Packages with Nuke and AppVeyor" /><published>2019-12-17T00:00:00-05:00</published><updated>2019-12-17T00:00:00-05:00</updated><id>https://cfrenzel.com/publishing-nuget-nuke-appveyor</id><content type="html" xml:base="https://cfrenzel.com/publishing-nuget-nuke-appveyor/">&lt;p&gt;This article builds on concepts discussed by &lt;a href=&quot;https://andrewlock.net/publishing-your-first-nuget-package-with-appveyor-and-myget/&quot;&gt;Andrew Lock&lt;/a&gt;, &lt;a href=&quot;https://lostechies.com/jimmybogard/2016/05/24/my-oss-cicd-pipeline/&quot;&gt;Jimmy Bogard&lt;/a&gt; and &lt;a href=&quot;https://blog.dangl.me/archive/escalating-automation-the-nuclear-option/&quot;&gt;Georg Dangl&lt;/a&gt;. Here we’re going use &lt;a href=&quot;https://nuke.build/&quot;&gt;Nuke&lt;/a&gt; to make build, packaging and publishing even nicer!!!&lt;/p&gt;

&lt;p&gt;I’ve been eking out build solutions using various Powershell based tools for years.  They serve their purpose, but I always dread getting familiar with the scripts again when I need to make a change.  I recently used &lt;a href=&quot;https://nuke.build/&quot;&gt;Nuke&lt;/a&gt; on a project and for the first time I feel like I didn’t waste any time fighting with it.&lt;/p&gt;

&lt;p&gt;Nuke creates a CSharp Console App within your solution containing a simple &lt;code&gt;Build.cs&lt;/code&gt; file that can handle a variety of common build/deployment tasks out of the box.  The real joy is that you can now author and debug platform independent build scripts in C# within your favorite IDE!&lt;/p&gt;

&lt;p&gt;Let’s jump in.&lt;/p&gt;

&lt;h4&gt;Using Nuke to Build&lt;/h4&gt;

&lt;ul&gt;
  &lt;li&gt;Install Nuke&lt;/li&gt;
&lt;/ul&gt;
&lt;pre&gt;
&amp;gt; dotnet tool install Nuke.GlobalTool --global
&lt;/pre&gt;

&lt;ul&gt;
  &lt;li&gt;Add Nuke to your solution - let the wizard get you started&lt;/li&gt;
&lt;/ul&gt;
&lt;pre&gt;
&amp;gt; nuke :setup
&lt;/pre&gt;
&lt;p&gt;&lt;img src=&quot;/assets/images/nuke-setup-screen.png&quot; alt=&quot;nuke setup&quot; title=&quot;nuke setup&quot; height=&quot;400&quot; /&gt;&lt;/p&gt;
&lt;div class=&quot;alert alert-warning&quot; role=&quot;alert&quot;&gt;
  &lt;strong&gt;Warning:&lt;/strong&gt; For me the Nuke build project defaulted to .NET Core 3.0.  This isn't necessarily a problem, but it's worth noting.  This was true when buidling an app on .NET Core 2.2; so it's a bit odd for my build environment to require .Net Core 3.0&lt;br /&gt;  
  TODO:/// Figure out Nuke's logic for framework selection and see if it's configurable     
&lt;/div&gt;

&lt;p&gt;You’ll notice a new project in your solution named &lt;code&gt;_build&lt;/code&gt;.  Take note of a few files&lt;/p&gt;
&lt;ol&gt;
  &lt;li&gt;&lt;code&gt;Build.cs&lt;/code&gt; - a fluent “make style” build Class in C#
    &lt;ul&gt;
      &lt;li&gt;Defines targets and their dependencies&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/li&gt;
  &lt;li&gt;Two scripts used to run builds.  These scripts will install dotnet if it doesn’t exist and then call your build application.  Choose one based on your build environment.
    &lt;ul&gt;
      &lt;li&gt;&lt;code&gt;build.ps1&lt;/code&gt; - a powershell script used to execute builds (platform independent - must have powershell installed)&lt;/li&gt;
      &lt;li&gt;&lt;code&gt;build.sh&lt;/code&gt; - a shell script version (linux/osx/etc..)&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/li&gt;
&lt;/ol&gt;

&lt;ul&gt;
  &lt;li&gt;Now compile your code&lt;/li&gt;
&lt;/ul&gt;
&lt;pre&gt;
&amp;gt;  .\build.ps1 Compile
&lt;/pre&gt;
&lt;p&gt;&lt;img src=&quot;/assets/images/nuke-compile-screen.png&quot; alt=&quot;nuke compile&quot; title=&quot;nuke compile&quot; height=&quot;600&quot; /&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Success!&lt;/strong&gt; I’ll admit that compiling a project isn’t that impressive, but we’re now scripting in C#.  Let’s take it a step further and make a NuGet package.&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;Add a &lt;strong&gt;Pack&lt;/strong&gt; step to our build script&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;n&quot;&gt;Target&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Pack&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_&lt;/span&gt;
      &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;DependsOn&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Compile&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
      &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Executes&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt;
      &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
          &lt;span class=&quot;nf&quot;&gt;DotNetPack&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;s&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;s&lt;/span&gt;
              &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetProject&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Solution&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;GetProject&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Nuke.Sample&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;))&lt;/span&gt;
              &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetConfiguration&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Configuration&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
              &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;EnableNoBuild&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
              &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;EnableNoRestore&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
              &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetDescription&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Sample package produced by NUKE&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
              &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetPackageTags&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;nuke demonstration c# library&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
              &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetNoDependencies&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;true&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
              &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetOutputDirectory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;ArtifactsDirectory&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;/&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;nuget&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;));&lt;/span&gt;

      &lt;span class=&quot;p&quot;&gt;});&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;We want our NuGet package to specify an author, repository, homepage, etc…  We could do this programatically from Nuke&lt;/p&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt; &lt;span class=&quot;n&quot;&gt;Target&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Pack&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_&lt;/span&gt;
      &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;DependsOn&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Compile&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
      &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Executes&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt;
      &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
          &lt;span class=&quot;nf&quot;&gt;DotNetPack&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;s&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;s&lt;/span&gt;
               &lt;span class=&quot;p&quot;&gt;***&lt;/span&gt;
              &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetAuthors&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;Your Name&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
              &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetPackageProjectUrl&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;https://github.com/yourrepo/NukeSample&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
               &lt;span class=&quot;p&quot;&gt;***&lt;/span&gt;
      &lt;span class=&quot;p&quot;&gt;});&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;But it’s simpler to add a &lt;code&gt;Directory.Build.props&lt;/code&gt; to your solution folder&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-xml highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt; &lt;span class=&quot;nt&quot;&gt;&amp;lt;Project&amp;gt;&lt;/span&gt;
  &lt;span class=&quot;nt&quot;&gt;&amp;lt;PropertyGroup&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;Authors&amp;gt;&lt;/span&gt;Your Name&lt;span class=&quot;nt&quot;&gt;&amp;lt;/Authors&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;RepositoryUrl&amp;gt;&lt;/span&gt;https://github.com/yourrepo/NukeSample&lt;span class=&quot;nt&quot;&gt;&amp;lt;/RepositoryUrl&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;PackageProjectUrl&amp;gt;&lt;/span&gt;https://github.com/yourrepo/NukeSample&lt;span class=&quot;nt&quot;&gt;&amp;lt;/PackageProjectUrl&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;PackageLicense&amp;gt;&lt;/span&gt;https://github.com/yourrepo/NukeSample/blob/master/LICENSE&lt;span class=&quot;nt&quot;&gt;&amp;lt;/PackageLicense&amp;gt;&lt;/span&gt;
  &lt;span class=&quot;nt&quot;&gt;&amp;lt;/PropertyGroup&amp;gt;&lt;/span&gt;
&lt;span class=&quot;nt&quot;&gt;&amp;lt;/Project&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;Now call our new &lt;strong&gt;Pack&lt;/strong&gt; target&lt;/li&gt;
&lt;/ul&gt;
&lt;pre&gt;
&amp;gt;  .\build.ps1 Pack
&lt;/pre&gt;

&lt;p&gt;Now we’ve got our nuget package: &lt;code&gt;artifacts\nuget\Nuke.Sample.1.0.0.nupkg&lt;/code&gt;.  If we unzip the .nupkg file we can take a look inside at our &lt;code&gt;Nuke.Sample.nuspec&lt;/code&gt; file.&lt;/p&gt;

&lt;div class=&quot;language-xml highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;cp&quot;&gt;&amp;lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&amp;gt;&lt;/span&gt;
&lt;span class=&quot;nt&quot;&gt;&amp;lt;package&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;xmlns=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;http://schemas.microsoft.com/packaging/2012/06/nuspec.xsd&quot;&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&amp;gt;&lt;/span&gt;
  &lt;span class=&quot;nt&quot;&gt;&amp;lt;metadata&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;id&amp;gt;&lt;/span&gt;Nuke.Sample&lt;span class=&quot;nt&quot;&gt;&amp;lt;/id&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;version&amp;gt;&lt;/span&gt;1.0.0&lt;span class=&quot;nt&quot;&gt;&amp;lt;/version&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;authors&amp;gt;&lt;/span&gt;Your Name&lt;span class=&quot;nt&quot;&gt;&amp;lt;/authors&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;owners&amp;gt;&lt;/span&gt;Your Name&lt;span class=&quot;nt&quot;&gt;&amp;lt;/owners&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;requireLicenseAcceptance&amp;gt;&lt;/span&gt;false&lt;span class=&quot;nt&quot;&gt;&amp;lt;/requireLicenseAcceptance&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;projectUrl&amp;gt;&lt;/span&gt;https://github.com/yourrepo/NukeSample&lt;span class=&quot;nt&quot;&gt;&amp;lt;/projectUrl&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;description&amp;gt;&lt;/span&gt;Sample package produced by NUKE&lt;span class=&quot;nt&quot;&gt;&amp;lt;/description&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;tags&amp;gt;&lt;/span&gt;nuke demonstration c# library&lt;span class=&quot;nt&quot;&gt;&amp;lt;/tags&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;repository&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;url=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;https://github.com/yourrepo/NukeSample&quot;&lt;/span&gt; &lt;span class=&quot;nt&quot;&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;dependencies&amp;gt;&lt;/span&gt;
      &lt;span class=&quot;nt&quot;&gt;&amp;lt;group&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;targetFramework=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;.NETStandard2.0&quot;&lt;/span&gt; &lt;span class=&quot;nt&quot;&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;/dependencies&amp;gt;&lt;/span&gt;
  &lt;span class=&quot;nt&quot;&gt;&amp;lt;/metadata&amp;gt;&lt;/span&gt;
&lt;span class=&quot;nt&quot;&gt;&amp;lt;/package&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;&lt;strong&gt;Success!&lt;/strong&gt;  Not bad for a few minutes of our time.  Before we move on let’s touch on versioning.  If you have an approach that you love, it shouldn’t be hard to work it into our current workflow with Nuke.  Here we’ll consider a manual option and using the popular &lt;a href=&quot;https://gitversion.readthedocs.io/en/latest/&quot;&gt;GitVersion&lt;/a&gt; tool.&lt;/p&gt;

&lt;h6&gt;Manual Versioning&lt;/h6&gt;
&lt;ul&gt;
  &lt;li&gt;Let’s add add a couple of lines to our &lt;code&gt;Directory.Build.props&lt;/code&gt;.&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-xml highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt; &lt;span class=&quot;nt&quot;&gt;&amp;lt;Project&amp;gt;&lt;/span&gt;
  &lt;span class=&quot;nt&quot;&gt;&amp;lt;PropertyGroup&amp;gt;&lt;/span&gt;
    ---
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;VersionPrefix&amp;gt;&lt;/span&gt;0.1.1&lt;span class=&quot;nt&quot;&gt;&amp;lt;/VersionPrefix&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;VersionSuffix&amp;gt;&lt;/span&gt;alpha&lt;span class=&quot;nt&quot;&gt;&amp;lt;/VersionSuffix&amp;gt;&lt;/span&gt;
  &lt;span class=&quot;nt&quot;&gt;&amp;lt;/PropertyGroup&amp;gt;&lt;/span&gt;
&lt;span class=&quot;nt&quot;&gt;&amp;lt;/Project&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;ul&gt;
  &lt;li&gt;Now let’s call our &lt;strong&gt;Pack&lt;/strong&gt; target again&lt;/li&gt;
&lt;/ul&gt;
&lt;pre&gt;
&amp;gt;  .\build.ps1 Pack
&lt;/pre&gt;

&lt;p&gt;Our package name reflects the new version: &lt;code&gt;artifacts\nuget\Nuke.Sample.0.1.1-alpha.nupkg&lt;/code&gt;.  If we unzip and look inside &lt;code&gt;Nuke.Sample.nuspec&lt;/code&gt; we can see the updated version.&lt;/p&gt;

&lt;div class=&quot;language-xml highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;&lt;span class=&quot;cp&quot;&gt;&amp;lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&amp;gt;&lt;/span&gt;
&lt;span class=&quot;nt&quot;&gt;&amp;lt;package&lt;/span&gt; &lt;span class=&quot;na&quot;&gt;xmlns=&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;http://schemas.microsoft.com/packaging/2012/06/nuspec.xsd&quot;&lt;/span&gt;&lt;span class=&quot;nt&quot;&gt;&amp;gt;&lt;/span&gt;
  &lt;span class=&quot;nt&quot;&gt;&amp;lt;metadata&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;id&amp;gt;&lt;/span&gt;Nuke.Sample&lt;span class=&quot;nt&quot;&gt;&amp;lt;/id&amp;gt;&lt;/span&gt;
    &lt;span class=&quot;nt&quot;&gt;&amp;lt;version&amp;gt;&lt;/span&gt;0.1.1-alpha&lt;span class=&quot;nt&quot;&gt;&amp;lt;/version&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;
&lt;h6&gt;Versioning with GitVersion tool&lt;/h6&gt;
&lt;p&gt;Nuke has great integration with the &lt;a href=&quot;https://gitversion.readthedocs.io/en/latest/&quot;&gt;GitVersion&lt;/a&gt; tool. You’ll need to read the &lt;a href=&quot;https://gitversion.readthedocs.io/en/latest/&quot;&gt;docs&lt;/a&gt; to fully understand how GitVersion determines the current version name for a branch, but to use - simply:&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;Add these 2 properties to your &lt;code&gt;Build.cs&lt;/code&gt; class
    &lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;  &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;GitRepository&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;readonly&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;GitRepository&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;GitRepository&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
  &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;GitVersion&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;k&quot;&gt;readonly&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;GitVersion&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;GitVersion&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;    &lt;/div&gt;
  &lt;/li&gt;
  &lt;li&gt;Add the &lt;code&gt;.SetVersion(GitVersion.NuGetVersionV2)&lt;/code&gt; to your &lt;strong&gt;Pack&lt;/strong&gt; Target
    &lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt; &lt;span class=&quot;nf&quot;&gt;DotNetPack&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;s&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;s&lt;/span&gt;
           &lt;span class=&quot;p&quot;&gt;---&lt;/span&gt;
          &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetVersion&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;GitVersion&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;NuGetVersionV2&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
          &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetNoDependencies&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;k&quot;&gt;true&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
          &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetOutputDirectory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;ArtifactsDirectory&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;/&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;nuget&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;));&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;    &lt;/div&gt;
    &lt;p&gt;Now GitVersion will work it’s magic to determine the current version name!&lt;/p&gt;
  &lt;/li&gt;
&lt;/ul&gt;

&lt;h5&gt;Publishing to a NuGet Repository with Nuke&lt;/h5&gt;

&lt;p&gt;Now that we have our source compiling and our package versioned and waiting in our artifacts folder, lets use Nuke to push it to a repository where it can be used by others.&lt;/p&gt;

&lt;p&gt;In order to make this as flexible as possible, we’ll pass the nuget repository’s url and auth_key as parameters to the Nuke build script.  Inside the script Nuke makes it easy for us to&lt;/p&gt;
&lt;ul&gt;
  &lt;li&gt;Require that it’s a Release build&lt;/li&gt;
  &lt;li&gt;Require that the url and auth_key have been set&lt;/li&gt;
  &lt;li&gt;
    &lt;p&gt;Get values from commandline / environment using c# fields&lt;/p&gt;
  &lt;/li&gt;
  &lt;li&gt;Add 2 Fields to to your Build file with the [Parameter] attribute&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;    &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Parameter&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;string&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;NugetApiUrl&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;https://api.nuget.org/v3/index.json&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt; &lt;span class=&quot;c1&quot;&gt;//default&lt;/span&gt;
    &lt;span class=&quot;p&quot;&gt;[&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Parameter&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;]&lt;/span&gt; &lt;span class=&quot;kt&quot;&gt;string&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;NugetApiKey&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;
&lt;ul&gt;
  &lt;li&gt;Add a &lt;strong&gt;Push&lt;/strong&gt; Target to your Build file&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;language-csharp highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt; &lt;span class=&quot;n&quot;&gt;Target&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Push&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;_&lt;/span&gt;
       &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;DependsOn&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Pack&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
       &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Requires&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;NugetApiUrl&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
       &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Requires&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;NugetApiKey&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
       &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Requires&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;Configuration&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Equals&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Configuration&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;Release&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;))&lt;/span&gt;
       &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Executes&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(()&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt;
       &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
           &lt;span class=&quot;nf&quot;&gt;GlobFiles&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;NugetDirectory&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;,&lt;/span&gt; &lt;span class=&quot;s&quot;&gt;&quot;*.nupkg&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
               &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;NotEmpty&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;()&lt;/span&gt;
               &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;Where&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;x&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;!&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;x&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;EndsWith&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s&quot;&gt;&quot;symbols.nupkg&quot;&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;))&lt;/span&gt;
               &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;ForEach&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;x&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt;
               &lt;span class=&quot;p&quot;&gt;{&lt;/span&gt;
                   &lt;span class=&quot;nf&quot;&gt;DotNetNuGetPush&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;s&lt;/span&gt; &lt;span class=&quot;p&quot;&gt;=&amp;gt;&lt;/span&gt; &lt;span class=&quot;n&quot;&gt;s&lt;/span&gt;
                       &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetTargetPath&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;x&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
                       &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetSource&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;NugetApiUrl&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
                       &lt;span class=&quot;p&quot;&gt;.&lt;/span&gt;&lt;span class=&quot;nf&quot;&gt;SetApiKey&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;n&quot;&gt;NugetApiKey&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
                   &lt;span class=&quot;p&quot;&gt;);&lt;/span&gt;
               &lt;span class=&quot;p&quot;&gt;});&lt;/span&gt;
       &lt;span class=&quot;p&quot;&gt;});&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;
&lt;ul&gt;
  &lt;li&gt;&lt;strong&gt;Push&lt;/strong&gt; to a NuGet repository&lt;/li&gt;
&lt;/ul&gt;
&lt;pre&gt;
&amp;gt; ./build.ps1 Push --NugetApiUrl &quot;https://api.nuget.org/v3/index.json&quot; --NugetApiKey &quot;yoursecretkey&quot;   
&lt;/pre&gt;

&lt;h4&gt;Using AppVeyor for Continuous Integration and Deployment&lt;/h4&gt;

&lt;p&gt;&lt;a href=&quot;https://www.appveyor.com/&quot;&gt;AppVeyor&lt;/a&gt; is a CI/CD tool with good support for windows/dotnet (and linux).  For open source projects you can setup a free account to build and deploy every time you publish changes to source control.  Here we’re going to use &lt;a href=&quot;https://www.github.com&quot;&gt;GitHub&lt;/a&gt;, but you could configure something similar with &lt;a href=&quot;https://azure.microsoft.com/en-us/services/devops/&quot;&gt;Azure DevOps&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;We’re going to build a popular workflow as described by &lt;a href=&quot;https://andrewlock.net/publishing-your-first-nuget-package-with-appveyor-and-myget/&quot;&gt;Andrew Lock&lt;/a&gt; and &lt;a href=&quot;https://lostechies.com/jimmybogard/2016/05/24/my-oss-cicd-pipeline/&quot;&gt;Jimmy Bogard&lt;/a&gt;.  It uses two seperate nuget repositories to publish under different conditions:&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;Build all commits on &lt;code&gt;master&lt;/code&gt; branch and publish to &lt;a href=&quot;https://www.myget.org/&quot;&gt;MyGet.org&lt;/a&gt;
    &lt;ul&gt;
      &lt;li&gt;Useful for reviewing and testing packages before releasing to the world&lt;/li&gt;
      &lt;li&gt;Nightly/experimental builds&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/li&gt;
  &lt;li&gt;If a commit is tagged we want to build and publish to &lt;a href=&quot;https://www.nuget.org/&quot;&gt;NuGet.org&lt;/a&gt;
    &lt;ul&gt;
      &lt;li&gt;Allows us to use git tags to control versioning and our intent to publish to the world&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/li&gt;
  &lt;li&gt;Build-only for pull request
    &lt;ul&gt;
      &lt;li&gt;We don’t want to publish a nuget package on pull requests, but we will confirm that the pull request builds&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;We can accomplish all of this with a simple appveyor.yml file.&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;Add &lt;code&gt;appveyor.yml&lt;/code&gt; to our root folder&lt;/li&gt;
&lt;/ul&gt;

&lt;div class=&quot;highlighter-rouge&quot;&gt;&lt;div class=&quot;highlight&quot;&gt;&lt;pre class=&quot;highlight&quot;&gt;&lt;code&gt;version: '{build}'
image: Ubuntu
environment:
MyGetApiKey:
    secure: 56nW3KcP4naYX9mlsVEIKLj5xPdfmpt6lMALR6wQmorRQOaoUOtlwMZ2V0BtGTAM
NugetApiKey:
    secure: /54XAunyBETRa1Fp/qSrwvebSnTAcHDO2OVZ+exMtQtOtrBzHKvp4RC1AB8RD2PQ
pull_requests:
do_not_increment_build_number: true
branches:
only:
- master
nuget:
disable_publish_on_pr: true
build_script:
- ps: ./build.ps1
test: off
deploy_script:
- ps: ./build.ps1 Pack
- ps: ./build.ps1 Push --NugetApiUrl &quot;https://www.myget.org/F/cfrenzel-ci/api/v2/package&quot; --NugetApiKey $env:MyGetApiKey
- ps: | 
    if ($env:APPVEYOR_REPO_TAG  -eq &quot;true&quot;){
        ./build.ps1 Push --NugetApiUrl &quot;https://api.nuget.org/v3/index.json&quot; --NugetApiKey $env:NugetApiKey
    }
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;/div&gt;

&lt;p&gt;There are a couple of important bits here&lt;/p&gt;
&lt;pre&gt;
build_script:
    - ps: ./build.ps1
&lt;/pre&gt;
&lt;p&gt;This tells appveyor to call our Nuke build script during the build phase&lt;/p&gt;
&lt;pre&gt;
 deploy_script:
    - ps: ./build.ps1 Pack
    - ps: ./build.ps1 Push --NugetApiUrl &quot;https://www.myget.org/F/cfrenzel-ci/api/v2/package&quot; --NugetApiKey $env:MyGetApiKey
    - ps: | 
        if ($env:APPVEYOR_REPO_TAG  -eq &quot;true&quot;){
            ./build.ps1 Push --NugetApiUrl &quot;https://api.nuget.org/v3/index.json&quot; --NugetApiKey $env:NugetApiKey
        }
&lt;/pre&gt;
&lt;p&gt;This tells appveyor to run a series of powershell commands during the Deploy phase.&lt;/p&gt;
&lt;ul&gt;
  &lt;li&gt;We call &lt;strong&gt;Pack&lt;/strong&gt; to create the nuget package.&lt;/li&gt;
  &lt;li&gt;Then we &lt;strong&gt;Push&lt;/strong&gt; it to MyGet.org using secure environment variables that we declared earlier&lt;/li&gt;
  &lt;li&gt;Then we check an appveyor environement variable &lt;code&gt;APPVEYOR_REPO_TAG&lt;/code&gt; to see if the branch has a tag&lt;/li&gt;
  &lt;li&gt;If it does we &lt;strong&gt;Push&lt;/strong&gt; to NuGet.Org&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;For a full working example with multiple nuget packages in a single solution checkout out my repo:&lt;/p&gt;

&lt;p&gt;&lt;a href=&quot;https://github.com/cfrenzel/Eventfully/blob/master/build/Build.cs&quot;&gt;https://github.com/cfrenzel/Eventfully/blob/master/build/Build.cs&lt;/a&gt;
&lt;a href=&quot;https://github.com/cfrenzel/Eventfully/blob/master/appveyor.yml&quot;&gt;https://github.com/cfrenzel/Eventfully/blob/master/appveyor.yml&lt;/a&gt;
&lt;a href=&quot;https://github.com/cfrenzel/Eventfully&quot;&gt;https://github.com/cfrenzel/Eventfully&lt;/a&gt;&lt;/p&gt;</content><author><name>camron</name></author><category term="featured" /><category term="appveyor" /><category term="nuke" /><category term="dotnet" /><category term="nuget" /><summary type="html">This article builds on concepts discussed by Andrew Lock, Jimmy Bogard and Georg Dangl. Here we’re going use Nuke to make build, packaging and publishing even nicer!!!</summary><media:thumbnail xmlns:media="http://search.yahoo.com/mrss/" url="https://cfrenzel.com/assets/images/nuke-appveyor-build-image.png" /></entry></feed>