topic Re: Field Injection for UserTasks in Alfresco Archive

Field Injection for UserTasks

prasanthnath_g — Fri, 19 Sep 2014 05:59:09 GMT

From the documentation, I see that field injection is supported for Service tasks. I just wanted to know if the same is supported for user tasks too. Something like this:<userTask id="auditPhase1" name="Audit Phase 1"> <extensionElements> <activiti:field name="actions" stringVa

Re: Field Injection for UserTasks

martin_grofcik — Fri, 19 Sep 2014 06:37:18 GMT

Hi Prasanth,

Yes it is supported.

Regards
Martin

Re: Field Injection for UserTasks

prasanthnath_g — Fri, 19 Sep 2014 12:38:07 GMT

I tried doing the same but could not get access to the fields. On debugging the code below, I am always getting extension elements(from which i can get fields) as empty map for the user task:
<java>
ProcessInstance processInstance = getProcessInstance(dataId);
BpmnModel model = getBpmnModelForProcessDefinition(processInstance.getProcessDefinitionId());
List<TaskDetail> taskDetails = Lists.newArrayList();
for(Object obj : model.getMainProcess().getFlowElements()) {
if(obj instanceof ServiceTask) {
ServiceTask serviceTask = (ServiceTask)obj;
taskDetails.add(new TaskDetail(serviceTask));
} else if(obj instanceof UserTask) {
UserTask userTask = (UserTask)obj;
Map<String, List<ExtensionElement>> extensionElements = userTask.getExtensionElements();
System.out.println(extensionElements);
taskDetails.add(new TaskDetail(userTask));
}
}
</java>

Is this the way to access the fields? Or do i need to access them in some other way?

Re: Field Injection for UserTasks

martin_grofcik — Fri, 19 Sep 2014 20:02:30 GMT

Hi Prasanth,

Did you check your process definition?
Try to add extension element to userTask


    <userTask id="usertask" name="Task" activiti:candidateGroups="dummy">
      <extensionElements>
        <activiti:newExtensionElement/>

and put break point :


        } else if (inExtensionElements) {
          ExtensionElement extensionElement = BpmnXMLUtil.parseExtensionElement(xtr);
          parentElement.addExtensionElement(extensionElement);
        }

Regards
Martin

Re: Field Injection for UserTasks

prasanthnath_g — Mon, 22 Sep 2014 04:45:18 GMT

Sorry. I did not get you. Here is how I have currently defined my user task:
<code>
<userTask id="audit1" name="Audit Phase 1" activiti:resultVariable="status">
<extensionElements>
<activiti:field name="actions" stringValue="Approve,Reject,Reprocess" />
</extensionElements>
</userTask>
</code>
I am using Activiti 5.15 as of now. What is activiti:newExtensionElement? Is this a new element supported by Activiti? Can I have more information on this?

Re: Field Injection for UserTasks

prasanthnath_g — Tue, 23 Sep 2014 10:54:55 GMT

Thanks for the pointer, Martin. After debugging the code, I found this line in FieldExtensionParser:
<java>
public void parseChildElement(XMLStreamReader xtr, BaseElement parentElement, BpmnModel model) throws Exception {

    if (parentElement instanceof ActivitiListener == false && parentElement instanceof ServiceTask == false &&
        parentElement instanceof SendTask == false) return;

    /** Code **/
}
</java>

So it seems for user tasks, I can not add fields. Can some one please suggest if there is any other way of achieving the same with user tasks?

Re: Field Injection for UserTasks

trademak — Wed, 24 Sep 2014 04:36:43 GMT

Hi Prasanth,

Field extensions are not supported for user tasks as is shown in your code example.
What you can do is add a field element in your own namespace. This field element will then be available in the BpmnModel object of your process definition which can be retrieved via the RepositoryService. When you lookup the UserTask object it will have extension elements which contains the field element values.

Best regards,

Re: Field Injection for UserTasks

prasanthnath_g — Wed, 24 Sep 2014 04:55:29 GMT

For getting this done, do I need to write some custom parser logic? It would be really helpful if you can share some example.

Re: Field Injection for UserTasks

trademak — Wed, 24 Sep 2014 06:03:19 GMT

No, you don't need any custom parser logic. The extension elements will be available in the user task by default if you add a custom extension element like:

<custom:field xmlns:custom="http://activiti.org/custom" name="actions" stringValue="Approve,Reject,Reprocess" />

Re: Field Injection for UserTasks

prasanthnath_g — Thu, 25 Sep 2014 06:49:23 GMT

It seems the example code you have posted is missing. Can you please repost it?

Re: Field Injection for UserTasks

prasanthnath_g — Sat, 27 Sep 2014 15:17:04 GMT

I tried doing this:
<code>
<userTask id="audit1" name="Audit Phase 1" activiti:resultVariable="status" xmlns:adaequare="http://www.adaequare.com/" >
<extensionElements>
<adaequare:field name="actions" stringValue="Approve,Reject,Reprocess" />
</extensionElements>
</userTask>
</code>

But even after this, on trying to read the user task extensionElements, extensionElements is coming as empty.

Re: Field Injection for UserTasks

martin_grofcik — Mon, 29 Sep 2014 07:10:08 GMT

Could you create jUnit test for it please?
http://forums.activiti.org/content/sticky-how-write-unit-test

Regards
Martin

Re: Field Injection for UserTasks

prasanthnath_g — Mon, 29 Sep 2014 08:33:30 GMT

I got a solution for this. Not sure if this is the right way to do it. But here is how I have done it:
<code>
<userTask id="audit1" name="Audit Phase 1" activiti:resultVariable="status" xmlns:adaequare="http://www.adaequare.com" adaequare:actions="Approve,Reject,Reprocess"></userTask>
</code>

And then I accessed the attributes from code like this:
<java>
List<ExtensionAttribute> userActionAtribute = userTask.getAttributes().get(WorkflowConstants.USER_ACTIONS);
if(CollectionUtils.isNotEmpty(userActionAtribute)){
ExtensionAttribute extensionAttribute = userActionAtribute.get(0);
String value = extensionAttribute.getValue();
if(StringUtils.isNotEmpty(value)){
taskDetail.getSupportedActions().addAll(Arrays.asList(value.split(StringConstants.COMMA)));
}
}
</java>