How to pass and display an array in the workflow's task?

[upforsin]

Hello,

After starting a workflow I populate ArrayList<String> in the TaskLsitener and i want to show its content in the workflow's tasks. How can i achieve that?

Freemarker supports arrays so creating an ftl shouldn't be a problem.

I can create variable of type "d:any" in the model, pass the value in the TaskListener but how to can retrive that values in the Freemarker template ?

So far I have created:

TaskListener:

List<String> myArray = new ArrayList<>();
// ..... (populating the array)
((ExecutionEntity)delegateTask.getExecution()).getProcessInstance().setVariable("my_myDataTest",myArray);

Model:

<property name="my:myDataTest">
   <type>d:any</type>
   <mandatory>false</mandatory>
</property>

Template:

<div id="${fieldHtmlId}-buttons"></div>
  <#list field.value as item>
    <b> ${item} </b>
 </#list>
</div>

I tried that  but I'm getting an error.  

my-project     | 2020-04-09 20:18:57,721  ERROR [freemarker.runtime] [http-nio-8080-exec-3] Error executing FreeMarker template
my-project     | FreeMarker template error:
my-project     | For "#list" list source: Expected a collection or sequence, but this evaluated to a string (wrapper: f.t.SimpleScalar):
my-project     | ==> field.value [in template "com/epmflow/my-data-test.ftl" at line 7, column 10]

my-project     | The failing instruction (FTL stack trace):
my-project     | ----------
my-project     |  ==> #list field.value as city [in template "com/epmflow/my-data-test.ftl" at line 7, column 3]
my-project     |     #include "\${field.control.template}"  [in template "org/alfresco/components/form/form.lib.ftl" in macro "renderField" at line 91, column 7]
my-project     |     @renderField field=form.fields[item.id]  [in template "org/alfresco/components/form/form.lib.ftl" in macro "renderSet" at line 122, column 13]
my-project     |     #else  [in template "org/alfresco/components/form/form.lib.ftl" in macro "renderSet" at line 121, column 10]
my-project     |     #else  [in template "org/alfresco/components/form/form.lib.ftl" in macro "renderSet" at line 117, column 4]
my-project     |     @formLib.renderSet set=item  [in template "org/alfresco/components/form/form.get.html.ftl" at line 39, column 28]
my-project     |     #if item.kind == "set"  [in template "org/alfresco/components/form/form.get.html.ftl" at line 37, column 22]
my-project     |     #nested  [in template "org/alfresco/components/form/form.lib.ftl" in macro "renderFormContainer" at line 64, column 10]
my-project     |     @formLib.renderFormContainer formId=f...  [in template "org/alfresco/components/form/form.get.html.ftl" at line 35, column 16]
my-project     |     #else  [in template "org/alfresco/components/form/form.get.html.ftl" at line 30, column 13]
my-project     |     #elseif form?exists  [in template "org/alfresco/components/form/form.get.html.ftl" at line 20, column 10]
my-project     |     @uniqueIdDiv  [in template "org/alfresco/components/form/form.get.html.ftl" at line 15, column 7]
my-project     |     @markup id="html"  [in template "org/alfresco/components/form/form.get.html.ftl" at line 14, column 4]
my-project     |     @standalone  [in template "org/alfresco/components/form/form.get.html.ftl" at line 1, column 1]
my-project     | ----------

When i use api-explorer, i can get the value (it's not a string)

      {
        "entry": {
          "name": "my_myDataTest",
          "type": "d:any",
          "value": [
            "one",
            "two",
            "three",
            "four"
          ]
        }

EDIT. I checked that the value is passed as a string "one,two,three,four". I can of couse split it by "," but then i could not use commas in the array. Is there a better way?