callbacks.md

NiftyServices documentation

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Callbacks

Here the most common callbacks list you can use to hook actions in run-time: (Hint: See all existent callbacks definitions in extensions/callbacks.rb file)

  - before_initialize
  - after_initialize
  - before_execute
  - after_execute
  - before_error
  - after_error
  - before_success
  - after_success

Creating custom Callbacks

Well, probably you will need to add custom callbacks to your services, in my case I need to save in database an object which tracks information about the environment used to create ALL RECORDS in my application, I was able to do it with just a few lines of code, see for yourself:

# Some monkey patch :)

NiftyServices::BaseCreateService.class_eval do
  ORIGIN_WHITELIST_ATTRIBUTES = [:provider, :locale, :user_agent, :ip]

  def origin_params(params = {})
    filter_hash(params.fetch(:origin, {}).to_h, ORIGIN_WHITELIST_ATTRIBUTES)
  end

  def create_origin(originable, params = {})
    return unless originable.respond_to?(:create_origin)
    return unless create_origin?

    originable.create_origin(origin_params(params))
  end

  # for records which we don't need to create origins, just
  # overwrite this method inside service class turning it off with:
  # return false
  def create_origin?
    Application::Config.create_origin_for_records
  end
end

# This register a callback for ALL services who inherit from `NiftyServices::BaseCreateService`
# In other words: Every and all records created in my application will be tracked
# I can believe that is easy like this, I need a beer right now!
NiftyServices::BaseCreateService.register_callback(:after_success, :create_origin_for_record) do
  create_origin(@record, @options)
end

Now, every record created in my application will have an associated origin object, really simple and cool!

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