Traceability of data on invoke

[MaheshkumarSundaram]

Hi @ralphhanna,

I would like to clarify something specific for User Tasks. I use bpmn-client from my react front-end to invoke user tasks.

Now, I can invoke like await client.engine.invoke(matchCriteria, output);

Say, my output for all user tasks is structured like { key1: 'value1', key2: 'value3' }.

This output is merged into instance's data. But in the next User Task, these values would be replaced by that particular new output.

But I would like to have a traceability of the data produced by User Tasks without one overwriting the other. How to achieve this?

Thank you.

[ralphhanna]

Hello @MaheshkumarSundaram
The intent of instance.data is to hold data elements common to the workflow
We also have item.vars to hold data elements specific to the item (instance of a specific node)

To store values in item.vars :

  item.vars = item.input;
  item.input = {}; // so instance.data will not save the input as usual

Please let me know if this meets your request?

Thanks

[MaheshkumarSundaram]

@ralphhanna But how to assign the data to item.vars while invoking? The data is provided by the users when completing a user task dynamically as required.

[ralphhanna]

Sorry, using ‘validate’ trigger Sent from my iPhone On Jun 11, 2024, at 3:43 PM, Maheshkumar Sundaram ***@***.***> wrote:  @ralphhanna<https://github.com/ralphhanna> But how to assign this while invoking? The data is provided by the users when completing a user task dynamically as required. — Reply to this email directly, view it on GitHub<#202 (reply in thread)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AC2XVKDXVI4RDOWYB635PU3ZG5HPHAVCNFSM6AAAAABJEDE2UCVHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM4TONBTGEYDC>. You are receiving this because you were mentioned.Message ID: ***@***.***>

[MaheshkumarSundaram]

@ralphhanna So sorry, I am failing to understand. Could you please give me an example of how would I call this using bpmn-client

[ralphhanna]

You need to modify the model:

[MaheshkumarSundaram]

Sorry @ralphhanna. But how does using validate help when I want to capture the data on invocation of a user task from bpmn-client? The data is not provided through forms directly. It's created by the application depending on the states in my react application. I'll only know the data before invocation.

[ralphhanna]

If I understand correctly, invoke executes validate before applying the data.
Please get latest release of bpmn-server.

https://bpmnserver.github.io/docs/execution/#engineinvoke

[ralphhanna]

Correction to earlier note, the correct syntax is as follows:

item.vars=item.input;
delete item.data.needsRepairs; // if you want to remove values from instance.data

[MaheshkumarSundaram]

@ralphhanna Thank you so much. This works fine 👍

Is there any plan to streamline handling UserTask's data in near future? Although this solution works, using validate for the above use case seems quite ambiguous as it's not validating anything essentially. Sorry if am nitpicking but just a thought.

It seems this can be done also using end Execution Listener. I just tested this. I prefer using the execution listener to do this as it seems right rather than validate. What do you think? Thanks.

[ralphhanna]

Hi @MaheshkumarSundaram
validate is done before completing the task and can return errors to reject the operation, while end can not reject the operation.
Not sure why it is not validating the user input.
Please give more details
Thanks

[MaheshkumarSundaram]

@ralphhanna, Sorry if I confused you. validate is fine. But for my use case, I don't need validate as I am not validating anything. So, I said I'll just use end listener.