Passing parameter value back from Child region [BTF] to Parent

Question

Hello,
I am using Jdev 11.1.1.6. I have a use-case where I need to pass value back from child taskflow to parent.
Let me elaborate the use-case:
I have a main page which is implemented as BTF with fragment. This main page contains a child region [again a BTF with fragment].
I am passing a parameter value from parent page to it's region using taskflow input parameter. Now value for one of the parameter changes inside child/region taskflow and I need to make this value available to main page taskflow.
This parameter is just pageFlowScope variable, so basically not coming from any VO.
I know that taskflow can return value via return parameter but I don't know if that is true for taskflow implemented as region in a page.
Is it possible to communicate the pageFlowScope variable value from child region to it's parent page?
Thanks,
Jai

Answer 1

Hi Frank,
I tried to follow steps mentioned in your post but encountered error that "The scope of the referenced object #{viewScope.parentBeanName} is shorter than referring object childBeanName"
Let me explain what I did:
1. Created a bean parentBeanName in viewScope
2. Created another bean childBeanName in pageFlowScope
3. In ChildBean.java, created a private property parentBeanProperty for Class [ParentBean] and generated the accessors
4. Created a input parameter in region TF as:
<input-parameter-definition id="__28">
      <name id="__27">parentBeanParam</name>
      <value>#{pageFlowScope.childBeanName.parentBeanProperty}</value>
      <class>ParentBean</class>
      <required/>
</input-parameter-definition> 5. Since my mainPage contains child page as region. I added parameter to mainPageDef to pass it to child TF, like this
<parameter id="parentBeanParam" xmlns="http://xmlns.oracle.com/adfm/uimodel"
                   value="#{viewScope.parentBeanName}"/>6. Introduced a client method in childBeanName that is called from UI. There I am retrieving parentBeanParam instance from pageFlowScope and call setter method of my variable inside ParentBean.java
7. Ran the page but encountered the error.
Did I miss something somewhere?
Initially I got error where #{viewScope.parentBeanName} returned NULL due to parentBeanName not instantiated. I created a variable in mainPageDef with it's default value pointing to #{viewScope.parentBeanName.variableName}, which I guess will instantiate the bean in viewScope.
After this I got error of shorter scope. It never reached to code in Step 6 during execution cycle.
FYI - My application is based on UIShell and essentially a one page application. Main page referred above is also a jsff based on BTF. I hope, this should not affect this implementation but I thought of at least mention it.
Thanks,
Jai
Edited by: Jai Om on Dec 18, 2012 2:38 PM