Configure InstanceName

Question

hi
Recently Steve Muench posted this discussion message
at http://groups.google.com/group/adf-methodology/msg/5b8bd1437d87b4e5
An ActionBinding can call backing bean method by using an EL expression in
the action binding's "InstanceName" attribute in the pageDef XML to
reference the bean in question. You still need to provide a data control
name that will be used for error handling. That might make for slightly
less intuitive backing bean code, but should solve the error handling issue. While trying to understand what this means, I created this example application using JDeveloper 11.1.1.3.0
at http://www.consideringred.com/files/oracle/2010/ConfigureInstanceNameApp-v0.01.zip
It has action-bindings configured like this...
  <bindings>
    <action id="myFailingServiceMethod" RequiresUpdateModel="true"
            Action="invokeMethod" MethodName="myFailingServiceMethod"
            IsViewObjectMethod="false" DataControl="ScottServiceDataControl"
            InstanceName="ScottServiceDataControl.dataProvider"/>
    <action id="myFailingBackingBeanMethod" RequiresUpdateModel="true"
            Action="invokeMethod" MethodName="myFailingBackingBeanMethod"
            IsViewObjectMethod="false" DataControl="ScottServiceDataControl"
            InstanceName="#{backingBeanScope.backing_browseEmpVO}"/>
  </bindings>
questions:
- (q1) Is the implementation in ConfigureInstanceNameApp-v0.01.zip what is intended by Steve Muench's suggestion?
- (q2) Which is exactly the "error handling issue" that should be resolved?
many thanks
Jan Vervecken

Answer 1

Thanks for your reply Steve.
- about the action-binding you posted
<action InstanceName="MyBean" MethodName="myMethod" id="CallBackingBeanMethod" />Its InstanceName does not use an EL expression, while you suggested "... using an EL expression in the action binding's "InstanceName" attribute ...".
- to review its behaviour I created some variations on "... an action binding like this in a binding container with no iterator bindings related to any data control and you don't specifically assign a data control to the <action> ..." in the example application
at http://www.consideringred.com/files/oracle/2010/ConfigureInstanceNameApp-v0.03.zip
- the page noDataControl.jspx has buttons like these ...
            <af:commandButton text="just myNoDCBackingBeanMethod" id="justCButton"
                              actionListener="#{backing_noDataControl.myNoDCBackingBeanMethod}"/>
            <af:commandButton text="do myNoDCBackingBeanMethodAction" id="cb1"
                              action="#{bindings.myNoDCBackingBeanMethodAction.execute}"/>
            <af:commandButton text="do myNoDCBackingBeanMethodNoELAction"
                              id="cb2"
                              action="#{bindings.myNoDCBackingBeanMethodNoELAction.execute}"/>... and noDataControlPageDef.xml looks like this ...
<pageDefinition xmlns="http://xmlns.oracle.com/adfm/uimodel"
                version="11.1.1.56.60" id="noDataControlPageDef"
                Package="configureinstancenameapp.view.pageDefs">
  <parameters/>
  <executables/>
  <bindings>
    <action id="myNoDCBackingBeanMethodAction" InstanceName="#{backing_noDataControl}" MethodName="myNoDCBackingBeanMethod"/>
    <action id="myNoDCBackingBeanMethodNoELAction" InstanceName="backing_noDataControl" MethodName="myNoDCBackingBeanMethod"/>
  </bindings>
</pageDefinition>- (sc1) the button "just myNoDCBackingBeanMethod" results in this stack-trace shown in the browser
javax.servlet.ServletException: a message for an exception thrown in the myNoDCBackingBeanMethod() method, pActionEvent.getSource() = RichCommandButton[UIXFacesBeanImpl, id=justCButton]
     at javax.faces.webapp.FacesServlet.service(FacesServlet.java:277)
     at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)
Caused by: javax.faces.FacesException: a message for an exception thrown in the myNoDCBackingBeanMethod() method, pActionEvent.getSource() = RichCommandButton[UIXFacesBeanImpl, id=justCButton]
     at configureinstancenameapp.view.backing.NoDataControl.myNoDCBackingBeanMethod(NoDataControl.java:16)
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
...- (sc2) the button "do myNoDCBackingBeanMethodAction" result in a dialog with message "DCInvokeMethod.null datacontrol" and this stack-trace in the log
java.lang.UnsupportedOperationException: DCInvokeMethod.null datacontrol
     at oracle.adf.model.binding.DCInvokeMethod.callMethod(DCInvokeMethod.java:229)
     at oracle.jbo.uicli.binding.JUCtrlActionBinding.doIt(JUCtrlActionBinding.java:1625)
     at oracle.jbo.uicli.binding.JUCtrlActionBinding.invoke(JUCtrlActionBinding.java:734)
     at oracle.adf.controller.v2.lifecycle.PageLifecycleImpl.executeEvent(PageLifecycleImpl.java:394)
     at oracle.adfinternal.view.faces.model.binding.FacesCtrlActionBinding._execute(FacesCtrlActionBinding.java:252)
     at oracle.adfinternal.view.faces.model.binding.FacesCtrlActionBinding.execute(FacesCtrlActionBinding.java:210)
     at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)- (sc3) the button "do myNoDCBackingBeanMethodNoELAction" behaves the same as the button "do myNoDCBackingBeanMethodAction"
- the page withDataControl.jspx has buttons like these ...
            <af:commandButton text="just myWithDCBackingBeanMethod" id="justCButton"
                              actionListener="#{backing_withDataControl.myWithDCBackingBeanMethod}"/>
            <af:commandButton text="do myWithDCBackingBeanMethodAction" id="cb1"
                              action="#{bindings.myWithDCBackingBeanMethodAction.execute}"/>
            <af:commandButton text="do myWithDCBackingBeanMethodNoELAction" id="cb2"
                              action="#{bindings.myWithDCBackingBeanMethodNoELAction.execute}"/>... and withDataControlPageDef.xml looks like this ...
<pageDefinition xmlns="http://xmlns.oracle.com/adfm/uimodel"
                version="11.1.1.56.60" id="withDataControlPageDef"
                Package="configureinstancenameapp.view.pageDefs">
  <parameters/>
  <executables>
    <variableIterator id="variables"/>
  </executables>
  <bindings>
    <action id="myWithDCBackingBeanMethodAction" InstanceName="#{backing_withDataControl}" MethodName="myWithDCBackingBeanMethod"
            DataControl="ScottServiceDataControl"/>
    <action id="myWithDCBackingBeanMethodNoELAction" InstanceName="backing_withDataControl" MethodName="myWithDCBackingBeanMethod"
            DataControl="ScottServiceDataControl"/>
  </bindings>
</pageDefinition>- (sc4) the button "just myWithDCBackingBeanMethod" results in this stack-trace shown in the browser
javax.servlet.ServletException: a message for an exception thrown in the myWithDCBackingBeanMethod() method, pActionEvent.getSource() = RichCommandButton[UIXFacesBeanImpl, id=justCButton]
     at javax.faces.webapp.FacesServlet.service(FacesServlet.java:277)
     at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)
Caused by: javax.faces.FacesException: a message for an exception thrown in the myWithDCBackingBeanMethod() method, pActionEvent.getSource() = RichCommandButton[UIXFacesBeanImpl, id=justCButton]
     at configureinstancenameapp.view.backing.WithDataControl.myWithDCBackingBeanMethod(WithDataControl.java:16)
...- (sc5) the button "do myWithDCBackingBeanMethodAction" does not seem to do anything at all, no message, no stack-trace
- (sc6) the button "do myWithDCBackingBeanMethodNoELAction" results in a dialog with message "Method backing_withDataControl.myWithDCBackingBeanMethod() not supported" and this stack-trace in the log
oracle.jbo.InvalidOperException: JBO-25221: Method backing_withDataControl.myWithDCBackingBeanMethod() not supported
     at oracle.adf.model.binding.DCInvokeMethod.invokeMethod(DCInvokeMethod.java:491)
     at oracle.adf.model.binding.DCDataControl.invokeMethod(DCDataControl.java:2134)
     at oracle.adf.model.bc4j.DCJboDataControl.invokeMethod(DCJboDataControl.java:3020)
     at oracle.adf.model.binding.DCInvokeMethod.callMethod(DCInvokeMethod.java:257)
     at oracle.jbo.uicli.binding.JUCtrlActionBinding.doIt(JUCtrlActionBinding.java:1625)
     at oracle.adf.model.binding.DCDataControl.invokeOperation(DCDataControl.java:2141)
     at oracle.jbo.uicli.binding.JUCtrlActionBinding.invoke(JUCtrlActionBinding.java:730)
     at oracle.adf.controller.v2.lifecycle.PageLifecycleImpl.executeEvent(PageLifecycleImpl.java:394)
     at oracle.adfinternal.view.faces.model.binding.FacesCtrlActionBinding._execute(FacesCtrlActionBinding.java:252)
     at oracle.adfinternal.view.faces.model.binding.FacesCtrlActionBinding.execute(FacesCtrlActionBinding.java:210)
     at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)All this does not become much clearer.
question
- (q3) Which design/suggestion/approach will bring you in a situation where "... an action binding like this in a binding container with no iterator bindings related to any data control and you don't specifically assign a data control to the <action> ..."?
regards
Jan Vervecken