External call when a task start

Camunda 7 Topics Discussion & Questions
1

Hi,
Is there a setting to call an external api when entering the task (or before entering the task(or userTask))? Also send the value of process Instance Id and form key?

thanks …

2

Hello @amir133 ,

for user tasks, there are task listeners.

They can be attached on various lifecycle events.

I hope this helps

Jonathan

3

thanks @jonathan.lukas .
Is it possible to give some examples?
Also how to get process Instance Id and form key in there?

4

may java delegate interface help you

2 Likes
5

thanks for Answer @Rasim_Savas
I don’t understand how to call an external link.
For example, I want to set, at the beginning of the usertask (or every userTask), XXX.com/get will be called and its output value will be added to the ‘condidateGroups’ variable.
Please note that my external link written in C# language, and it is located at a different address than Camunda.
Can you help me?

6

camunda does just node.js and java support. so you need c# program have to write yourself. but this project some action provide for camunda external client.

1 Like
7

Here is another helpful collection:

Jonathan

8

thanks @jonathan.lukas
finally I found my answer , I am using groovy to call my api like this:

<camunda:executionListener event="start">
  <camunda:script scriptFormat="groovy">
    import groovy.json.JsonSlurper 
    def formkey = "345435" // need access to formKey!!!!!!!!!!!!!!!!!!!!!
    def jsonSlurper = new JsonSlurper().parseText(("https://XXX.com/GetGroupsByFormKey?formKey="+formkey).toURL().text) 
    //...
  </camunda:script>
</camunda:executionListener>

But need access to extensionElements like processInstaceId and formKey. I used these, but no one worked!!!

def formkey = formKey // not worked
def formkey = task.formKey // not worked
def formkey = execution.formKey // not worked

@jonathan.lukas , @Rasim_Savas Do you have any Idea?

9

Hello @amir133 ,

instead of an ExecutionListener, you can use a taskListener (which is only possible on a user task)

Jonathan

1 Like
10

Thanks @jonathan.lukas

So how can I access the value of formKey and processInstaceId?

12

look here, you need DelegateTask or DelegateExecution interfaces. access everything.

https://docs.camunda.org/javadoc/camunda-bpm-platform/7.16/org/camunda/bpm/engine/delegate/DelegateExecution.html

https://docs.camunda.org/javadoc/camunda-bpm-platform/7.2/org/camunda/bpm/engine/delegate/TaskListener.html

2 Likes
13

Hi @amir133,

If a task listener is used as suggested by @jonathan.lukas then you can access formKey as in below
task.bpmnModelElementInstance.camundaFormKey

image
image783×334 9.35 KB

1 Like
14

Thanks @Rasim_Savas and @hassang