Add taskflow at runtime

Question

Does anybody know how i can add a taskflow at runtime.
SUppose i have a button and when the user clicks the button, a taskflow should be add to a parent component.
We can create a region to the component when the button is clicked but the difficult part is how to add the taskflow binding to that region. We should add the executable binding at runtime and that appears to be not so straightforward.
This is what i've got so far
BindingContext vBindingContext = BindingContext.getCurrent();
        DCBindingContainer bc =
                vBindingContext.findBindingContainer(
                "view_testPageDef");
        List exs = bc.getExecutableBindings();
        Iterator it = exs.iterator();
        while(it.hasNext()) {
            Object o = it.next();
            DCTaskFlowBinding binding = (DCTaskFlowBinding)it.next();
            System.out.println("Class:" + o.getClass());           
        DCTaskFlowBinding newBinding =  new DCTaskFlowBinding();As you can see we get the list of the executable bindings that are in our pagedef so far.
The step i am missing is how to set the taskflow ID to the DCTaskFlowBinding. It has a getter for the taskflow id but not a setter.
Is their a factory class to achieve this or how should i approach this?

Answer 1

hi Yannick
Please consider this example application created using JDeveloper 11.1.1.3.0
http://www.consideringred.com/files/oracle/2010/DynamicTaskflowBindingsApp-v0.01.zip
Similar to what I tried in Re: binding wrapper methods and Page Definition beans the idea is to use the definition of an existing task-flow executable binding to create new task-flow executable bindings. To be able to use these new bindings on a page, a list of binding expressions is managed and used in an af:forEach component to add af:region tags/components .
protected DCBindingContainer findOrCreateTaskflowExecutable(
     String pTasflowExecutableId, String pExistingTaskflowExecutableId)
     DCBindingContainer vTaskflowExecutable =
          findTaskflowExecutable(pTasflowExecutableId);
     if (vTaskflowExecutable == null)
          BindingContainer vBindings = getBindings();
          DCBindingContainer vExistingTaskflowExecutable =
               findTaskflowExecutable(pExistingTaskflowExecutableId);
          DCBindingContainerDef vDCBindingContainerDef =
               vExistingTaskflowExecutable.getDef();
          Object vExecutableBinding =
               vDCBindingContainerDef.createExecutableBinding(
                    BindingContext.getCurrent(), (DCBindingContainer)vBindings);
          vTaskflowExecutable = (DCBindingContainer)vExecutableBinding;
          vTaskflowExecutable.setName(pTasflowExecutableId);
          DCBindingContainer vDCBindings = (DCBindingContainer)vBindings;
          vDCBindings.addExecutableBinding(vTaskflowExecutable);
     return vTaskflowExecutable;
     <af:forEach items="#{backing_dsctfManager.leftBindingsList}"
              var="tfbinding">
       <af:outputText value="#{tfbinding}" id="ot1"/>
       <af:region value="#{tfbinding.regionModel}" id="r2"/>
     </af:forEach>This screencast shows how this behaves at run-time
http://www.screentoaster.com/watch/stUEpQSkxIR15bQF5aWFhZXl5X/dynamictaskflowbindingsapp
(Note that approaches focused on the RichRegion component seem to have a problem because it is the af:region tag that allows the task-flow to be included (using PageContext.include()) and even if that is simulated, the absence of an af:region tag causes an IllegalStateException in the UIComponentClassicTagBase.doStartTag() for components in the task-flow with the same ID as one of the components in the page it is included (see also mojarra-1.2_09-b02-FCS-source.zip), and even if that is avoided the task-flow somehow shows up on the page but does not behave as expected, so ... it looks like the af:region tag plays an important role here.)
Anyway, I don't know if any of this is supported by Oracle, or if it is robust, or anything else ... it just "does something" with new task-flow executable bindings.
regards
Jan Vervecken