Unknown property used in expression

[alfsender]

Hi All,

I am creating Activiti workflow, but i am getting below exception..

org.activiti.engine.ActivitiException: Unknown property used in expression‍

Below code is my process definition file, I am creating a process where initiator start workflow and assign it to one user, that user can assign task to any other user.. this can continue n number of time, until any one rejects the flow, which will end the workflow. So here in approve I am assigning same task to itself.

      <?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:activiti="http://activiti.org/bpmn"
   xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC"
   xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema"
   expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="http://www.activiti.org/test">
   <process id="techWf" name="Tech Specialist Limited Workflow" isExecutable="true">

      <!– Start/Initiate Workflow Task –>
      <startEvent id="initiateWorkflow" name="Initiate Review" activiti:formKey="tslwf:startTask"></startEvent>

      <sequenceFlow id='flow1' sourceRef='initiateWorkflow' targetRef='reviewTaskOne' />

      <!– User Review Workflow Task One –>
      <userTask id="reviewTaskOne" name="Review Task" activiti:formKey="tslwf:reviewTaskOne">
         <extensionElements>
            <activiti:taskListener event="create"
               class="org.alfresco.repo.workflow.activiti.tasklistener.ScriptTaskListener">
               <activiti:field name="script">
                  <activiti:string>
                     task.setVariable("bpm_assignee", "");
                     if (typeof bpm_workflowDueDate != 'undefined') task.dueDate = bpm_workflowDueDate;
                     if (typeof bpm_workflowPriority != 'undefined') task.priority = bpm_workflowPriority;
                        </activiti:string>
               </activiti:field>
            </activiti:taskListener>
            <activiti:taskListener event="complete" class="org.alfresco.repo.workflow.activiti.tasklistener.ScriptTaskListener">
               <activiti:field name="script">
                  <activiti:string>
                     logger.log("—->" + task.getVariable('tslwf_reviewOutcome'));
                     execution.setVariable('tslwf_reviewOutcome', task.getVariable('tslwf_reviewOutcome'));
                     logger.log("—-> Variable Assigned " + execution.getVariable('tslwf_reviewOutcome'));
                  </activiti:string>
               </activiti:field>
            </activiti:taskListener>
         </extensionElements>
         <humanPerformer>
            <resourceAssignmentExpression>
               <formalExpression>${bpm_assignee.properties.userName}</formalExpression>
            </resourceAssignmentExpression>
         </humanPerformer>
      </userTask>
      
      <sequenceFlow id="flow2" targetRef="reviewDecisionOne" sourceRef="reviewTaskOne"></sequenceFlow>

      <!– Review Decision –>
      <exclusiveGateway id="reviewDecisionOne" name="Review Decision" />
      
      <sequenceFlow id="flow3" sourceRef="reviewDecisionOne" targetRef="reviewTaskOne">
         <extensionElements>
            <activiti:executionListener event="take" class="org.alfresco.repo.workflow.activiti.listener.ScriptExecutionListener">
               <activiti:field name="script">
                  <activiti:string>
                     logger.log("—-> In Sequence Flow " + execution.getVariable('tslwf_reviewOutcome'));
                  </activiti:string>
               </activiti:field>
            </activiti:executionListener>
         </extensionElements>
         <conditionExpression xsi:type="tFormalExpression">${tslwf_reviewOutcome == 'Approve'}</conditionExpression>
      </sequenceFlow>

      <sequenceFlow id="flow4" sourceRef="reviewDecisionOne" targetRef="endFlow" />

      <!– End Workflow Task –>
      <endEvent id="endFlow" name="End"></endEvent>
   </process>
</definitions>
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I have enabled server logs, so I am getting below logs

 2014-06-08 00:55:19,556  DEBUG [repo.jscript.ScriptLogger] [http-9090-9] —->Approve
 2014-06-08 00:55:19,559  DEBUG [repo.jscript.ScriptLogger] [http-9090-9] —-> Variable Assigned Approve
 2014-06-08 00:55:19,568  DEBUG [repo.jscript.ScriptLogger] [http-9090-9] —-> In Sequence Flow Approve
 2014-06-08 00:55:19,569  DEBUG [repo.jscript.ScriptLogger] [http-9090-9] org.activiti.engine.ActivitiException: Unknown property used in expression
 2014-06-08 00:55:19,570  DEBUG [repo.jscript.ScriptLogger] [http-9090-9] Returning 500 status code
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Below is my workflow model

<?xml version="1.0" encoding="UTF-8"?>

<model name="tslwf:contentModel" xmlns="http://www.alfresco.org/model/dictionary/1.0">

   <imports>
      <import uri="http://www.alfresco.org/model/dictionary/1.0" prefix="d" />
      <import uri="http://www.alfresco.org/model/bpm/1.0" prefix="bpm" />
      <import uri="http://www.alfresco.org/model/content/1.0" prefix="cm" />
   </imports>

   <namespaces>
      <namespace uri="http://www.techdemo.com/model/workflow/1.0" prefix="tslwf" />
   </namespaces>
   
   <types>
      
      <!– Start Task –>
      <type name="tslwf:startTask">
         <parent>bpm:startTask</parent>
         <mandatory-aspects>
            <aspect>bpm:assignee</aspect>
         </mandatory-aspects>
      </type>
      
      <!– Review Task One –>
      <type name="tslwf:reviewTaskOne">
         <parent>bpm:activitiOutcomeTask</parent>
         <properties>
            <property name="tslwf:reviewOutcome">
               <type>d:text</type>
               <default>Reject</default>
               <constraints>
                  <constraint name="tslwf:reviewOutcomeOptions" type="LIST">
                     <parameter name="allowedValues">
                        <list>
                           <value>Approve</value>
                           <value>Reject</value>
                        </list>
                     </parameter>
                  </constraint>
               </constraints>
            </property>
         </properties>
         <overrides>
            <property name="bpm:packageItemActionGroup">
               <default>edit_package_item_actions</default>
            </property>
            <property name="bpm:outcomePropertyName">
               <default>{http://www.techdemo.com/model/workflow/1.0}reviewOutcome</default>
            </property>
         </overrides>
         <mandatory-aspects>
            <aspect>bpm:assignee</aspect>
         </mandatory-aspects>
      </type>
      
   </types>
   
   <aspects>
   </aspects>
</model>
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Means its coming properly in sequenceFlow and getting value properly using execution.getVariable('tslwf_reviewOutcome'), but in "tFormalExpression", its giving this error, not sure why its not able to find that variable. Let me know if there is other way around to achieve this.

Request you to send me your valuable suggestion.

Thank you.

[lementree]

Hi Can you try as below in condition:

<conditionExpression xsi:type="tFormalExpression"><![CDATA[${execution.getVariable("tslwf_reviewOutcome")=="Approve"}]]></conditionExpression>
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[alfsender]

Hi Sagar,

Thanks for the response, I already tried that but it didn't worked as well.

Just wanted to check one thing is, I have below type in my workflow content model.

      <type name="tslwf:reviewTaskOne">
         <parent>bpm:activitiOutcomeTask</parent>
         <properties>
            <property name="tslwf:userComment">
               <type>d:text</type>
            </property>
            <property name="tslwf:reviewOutcome">
               <type>d:text</type>
               <default>Reject</default>
               <constraints>
                  <constraint name="tslwf:reviewOutcomeOptions" type="LIST">
                     <parameter name="allowedValues">
                        <list>
                           <value>Approve</value>
                           <value>Reject</value>
                        </list>
                     </parameter>
                  </constraint>
               </constraints>
            </property>
         </properties>
         <overrides>
            <property name="bpm:packageItemActionGroup">
               <default>edit_package_item_actions</default>
            </property>
            <property name="bpm:outcomePropertyName">
               <default>{http://www.techspecialistlimited.com/model/workflow/1.0}reviewOutcome</default>
            </property>
         </overrides>
         <mandatory-aspects>
            <aspect>tslwf:assignee</aspect>
         </mandatory-aspects>
      </type>

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As I have given outcome as Approve and Reject, when I load form of this task, both the buttons are coming as disabled, when I select user (tslwf:assignee) then only they get enabled. On reject I am ending workflow, on approve task gets assigned to user selected.

So if user wants to reject (means end) the flow, then also he/she has to select any user in order to enable the button.

I want Reject button to be enabled by default, and approve to be disabled. When user select any approver in tslwf:assignee, then only it should get enabled.

Let me know your inputs.

Regards.

[lementree]

Hi,

Unfortunately we cant disable/enable transitions depending upon form values, but you can handle value in complete event.dont make the assignee as mandatory in form, then check for the value in Complete event depending upon the out come, if the out come is Approve and Assignee is not selected then throw error.

[alfsender]

Thanks, eventually I used the same approach as your.

Thanks once again.

Regards.