Failed to execute supplied script: Couldn't serialize value 'org.mozilla.javascript.NativeArray

mtsiak

I am trying to set the users list that can execute a user task.
So, the user task is something like:

<userTask id="userTask1" name="Review" 
  activiti:assignee="${myflow_reviewassignee.properties.userName}" 
  activiti:formKey="myflow:review">
    ...
    <multiInstanceLoopCharacteristics isSequential="false" 
       activiti:collection="myflow_supervisors" 
       activiti:elementVariable="myflow_reviewassignee">
        <completionCondition>${myflow_reviewapprovalcount != 0}</completionCondition>
      </multiInstanceLoopCharacteristics>
</userTask>

While in a previous serviceTask i am trying to set the user list 'supervisors'

var group = people.getGroup("GROUP_agroup");
var supervisors = people.getMembers(group); 
execution.setVariable("myflow_supervisors", supervisors); 
...

But i get the error

org.alfresco.scripts.ScriptException: 06040011 Failed to execute supplied script: 
Couldn't serialize value 'org.mozilla.javascript.NativeArray@28879284' 
in variable 'myflow_supervisors'
Returning 500 status code

Any ideas?

Meanwhile, but for other workflows, if i add a rule on a folder, that starts a workflow when a user uploads a new documents, the workflow start with no errors.

var workflow = actions.create("start-workflow");
//...
var group = people.getGroup("GROUP_agroup");
workflow.parameters["mymodel:peoplelist"] = people.getMembers(group); 
//...
workflow.execute(document);

Is there any difference between 'workflow.parameters' and 'execution.setVariable' ?

afaust

All the actions you create in JavaScript are handled specially with regards to JavaScript parameters as these JavaScript values are converted to proper Java instances before the actual execution. This means that using the parameters on the workflow action, a JavaScript array (NativeArray) will be converted into a Java List, and that is why it works. The "execution" object is a standard Activiti Java object without any special JavaScript integration layer, so any JavaScript value you try to set as a variable will not be converted to Java, and since Activiti does not know how to handle (most) JavaScript types, it fails with the exception that you have.

Most of the time, you cannot set any of the array-like values you can obtain from Alfresco root scope objects as variable values in Activiti without applying some mapping logic. I.e. you could create custom Java classes as extensions to the JavaScript API to map those values before you set them in the execution.

Of course you can always use the trick Krutik Jayswal‌ mentioned about converting the values to some stringified representation. Just be aware that you then would have to make sure you can also re-resolve the real values from the stringified representation when you need to, i.e. read the variables in another task / listener / delegate expression.