Declared value has type org.activiti.engine.impl.el.Fixed

[dognose]

Hello Guys,

i'm currently working with Custom Extensions for the Designer.
What i'm trying to do, is setup a Mail-Task that uses my internal template-system
for sending mails.

The extension of AbstractCustomServiceTask declares 2 fields: mailTemplateID (String) and receiver (string)
So, i also added those 2 Attributes to the JavaDelegate that should call my mailService-Instance.

however, i get an exception, when the execution arrives at this task:

07:20:48,812 SCHWERWIEGEND [org.activiti.engine.impl.interceptor.CommandContext] (http–0.0.0.0-8090-3) Error while closing command context: org.activiti.engine.ActivitiException: Incompatible type set on field declaration 'mailTemplateID' for class taskDelegations.MyMailTaskDelegation. Declared value has type org.activiti.engine.impl.el.FixedValue, while expecting java.lang.String
   at org.activiti.engine.impl.bpmn.helper.ClassDelegate.applyFieldDeclaration(ClassDelegate.java:192) [activiti-engine-5.10.jar:5.10]
   at org.activiti.engine.impl.bpmn.helper.ClassDelegate.instantiateDelegate(ClassDelegate.java:165) [activiti-engine-5.10.jar:5.10]
   at org.activiti.engine.impl.bpmn.helper.ClassDelegate.getActivityBehaviorInstance(ClassDelegate.java:135) [activiti-engine-5.10.jar:5.10]
   at org.activiti.engine.impl.bpmn.helper.ClassDelegate.execute(ClassDelegate.java:112) [activiti-engine-5.10.jar:5.10]
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:44) [activiti-engine-5.10.jar:5.10]
…
‍‍‍‍‍‍‍‍‍

Any hints?

[frederikherema1]

Fields used by field-injection should be of type "Expression", and should be resolved when needed, using the passed-in DelegateExecution in the execute() method:


public class ReverseStringsFieldInjected implements JavaDelegate {

  private Expression text1;
  private Expression text2;

  public void execute(DelegateExecution execution) {
    String value1 = (String) text1.getValue(execution);
    execution.setVariable("var1", new StringBuffer(value1).reverse().toString());

    String value2 = (String) text2.getValue(execution);
    execution.setVariable("var2", new StringBuffer(value2).reverse().toString());
  }
}


[dognose]

Sry, got to dig this out again:

I'm now using The Expressions as mentioned above:

public class MyMailTaskDelegation implements org.activiti.engine.delegate.JavaDelegate {

private Expression mailTemplateId;
private Expression internalUserId;
private Expression externalAdress;
private Expression externalName;

@Override
public void execute(DelegateExecution execution) throws Exception {


with the implementation of the AbstractCustomServiceTask as follows:


@Runtime(delegationClass = MyMailTask.DELEGATION)
public class MyMailTask extends AbstractCustomServiceTask {
  /*
…
static strings here
…
*/
   @Property(type = PropertyType.TEXT, displayName = MyMailTask.FIELD_NAME_TEMPLATE_ID, required = true)
@Help(displayHelpShort = MyMailTask.FIELD_HELP_TEMPLATE_ID)
private String mailTemplateId;

@Property(type = PropertyType.TEXT, displayName = MyMailTask.FIELD_NAME_INTERNAL)
@Help(displayHelpShort = MyMailTask.FIELD_HELP_INTERNAL)
private String internalUserId;

@Property(type = PropertyType.TEXT, displayName = MyMailTask.FIELD_NAME_EXTERNAL_MAIL)
@Help(displayHelpShort = MyMailTask.FIELD_HELP_EXTERNAL_MAIL)
private String externalAdress;

@Property(type = PropertyType.TEXT, displayName = MyMailTask.FIELD_NAME_EXTERNAL_NAME)
@Help(displayHelpShort = MyMailTask.FIELD_HELP_EXTERNAL_NAME)
private String externalName;

now, in Designer i set
templateId=LostPassword
internalUserId=#{requestingUserId}

However, Activiti injects the internalUserId as an Instance of Type FixedValue and therefore getValue() will return #{requestingUserId}
instead of 4878 or whatever evaluated id of given user.

Do i need to mark the Properties as "dynamic" in any way?

I noticed that the Designer generates the following XML:


<serviceTask id="servicetask3" name="MyMailTask" activiti:class="my.namespace.taskDelegations.MyMailTaskDelegation">
      <extensionElements>
        <activiti:field name="mailTemplateId">
          <activiti:string>LostPassword</activiti:string>
        </activiti:field>
        <activiti:field name="internalUserId">
          <activiti:string>${requestingUserId}</activiti:string>
        </activiti:field>
      </extensionElements>
    </serviceTask>

but should be


<serviceTask id="servicetask3" name="MyMailTask" activiti:class="my.namespace.taskDelegations.MyMailTaskDelegation">
      <extensionElements>
        <activiti:field name="mailTemplateId">
          <activiti:string>LostPassword</activiti:string>
        </activiti:field>
        <activiti:field name="internalUserId">
          <activiti:expression>${requestingUserId}</activiti:expression>
        </activiti:field>
      </extensionElements>
    </serviceTask>

So, is this a designer "Bug", or is it because the Properties in "MyMailTask" are defined as Strings?
But i cannot declare them as Expression or JuelExpression, because the namespace org.activiti.engine.impl.el is not available
in the DesignerExtension project.

Edit:
If i manually change the XML from <activiti:string> to <activiti:expression> it works as expected.

[dognose]

giving this a tiny bump:

How can i make activiti to generate <activiti:expression> instead of <activiti:string> in the resulting XML file?
(see example from last post)

[trademak]

Hi,

Which version of the Designer are you using? This is working in the latest release.

Best regards,

[dognose]

Updated to the latest version.
You're right. It works now as expected