Camunda REST - Retrieve Task Extension Properties

Camunda 7 Topics Discussion & Questions
1

Hi.

I’m defined some extension properties on my tasks and I need to retrieve then using the Rest API. Which method should I use?

2

Hi @edgarberlinck,

There is no Rest API where you can retrieve the properties from.

You could implement your own Rest point where you can retrieve the properties from by using the camunda-bpmn-model-api 1.

What is the purpose of having such properties?

Cheers,
Roman

3

Hi @roman.smirnov

Because I want use to store some custom values to use on my application :frowning:

4

Yeah second this request, this will allow using general worker from C#. (via REST)

5

@jchonc @edgarberlinck how about something like this:

Look at the first example. Where you can have a Json file that you keep your config stored in. I find this be be much more clean

6

Thanks Stephen. I am a total newbie for camunda so please forgive me.

My question is more for GitHub - berndruecker/camunda-csharp-showcase: Showcase using Camunda BPM on .NET Platform with C# (no Java Coding required!), especially if I put in some more the extensionElements into a service task, like

<bpmn2:extensionElements>
        <camunda:field name="roleName">
          <camunda:string>xxyy</camunda:string>
        </camunda:field>
      </bpmn2:extensionElements>

Then how can I retrieve those values from the C# worker.

The goal is to have a generic worker to handle several notifications based upon the variable.
i.e. Notification for submitter, Notification for Nurse…

Thanks in advance.

7

You would have the worker get variables(process or local) or you could submit the values of the variables into the worker when you send the task to the worker.

8

Can you share some of your use case? And maybe a generic version of your process?

9

Thanks Stephen.

My simple test BPMN goes more or less like

(receive incident)->(a.notify submitter about reception)->(b. human task.)-> (c.notify submitter about resolution)->(end)

So both (a) and © are notifying the person who submit the file, but using different form letters. Thus I was thinking about using the same worker and just have 1 parameter to indicate which form letter to populate and send. Does that make any sense?

Thanks again and have a good weekend.

10

So to simplify. How about you build a web microservice (in c#?) that sends emails/messages/texts/whatever. And then use a service task configured with camunda http-connector. You can then configure the HTTP call to whatever POST payload you need for the two different scenarios.

Here are two examples:

11

Thank you Stephen, yeah that’ll definitely work, however allow end-user BA to configure http-connector might be a bit dangerous… (I was planning to expose web modeler in application). Currently I am using your first approach, but parsing the BPMN/XML in my own code to retrieve those fields. That’s why I wish to access those values from REST…

Thank you for your help.

12

id exposing the http connectors are a concern you could use a message event to message another process or use the call activity task to start a subprocess which would be your message/alert tasks.

13