JDeveloper & ADF: Carefully Select the Data Control Scope of Bounded Task Flows

A customer asked me to look into an error which showed up in one of their applications. Without going into the details of real use case I like to bring this issue to your attention as it might happen to you too.

Use Case
I set up a mock use case to show the problem as this: A page (.jspx or .jsf) includes one (or more) other task flows as a region. The base page retrieves some data using a method call exposed in the data control, which should be displayed in the region for information purpose.

If the task flows share their data controls this is not a big deal to implement this. You can download the sample using the link provided at the end of this blog. The sample uses the HR schema and was build using JDev and was additional tested with JDev and JDev, which show the same behavior.

On the base page I set up an inputText which I use to pass a parameter to the method (callMeTest) which retrieves some info from the application module. The callMeTest method simply returns the passed parameter together with a ‘nice’ message:

    public String callMeTest(String name) {
        _logger.info("Called with: "+name);
        return "Call me Test "+name;

The return value is then displayed on the base page at the bottom under the button and should be displayed in the region, under the table, too. The sample just uses one region. When no value is present ‘****’ is used as parameter. The image below shows the application after starting it.

Start Screen

Start Screen

After entering a value into the inputText field below the table and hitting the ‘callMeTest’ button underneath it, you see that the return value is displayed below the button on the base page and under the table inside the region. If the button is hit with another value, both values are updated.

After entering a value and hitting the button

After entering a value and hitting the button

Nothing unusual so far. Now, for some unknown reason, after a change to another part the application, that functionality did not work any longer. The value in the base page still updates after the call to the method, but the value in the region stopped updating.

Screen after next deployment

Screen after next deployment

The reason for this behavior is a simple one. A look into the task flow properties of the region, revealed that the checkmark for the ‘Share data controls with calling task flow’ was not set, meaning that the task flow get its own data control frame. The result is that the method outcome from the base page is not visible in the region.

TaskFlow properties (1)

TaskFlow properties (1)

The question was how did this happen, when the change which results in the new deployment had nothing to do with this part of the application?

It turned out, that when you create a new bounded task flow this property value is set to ‘default’. This is shown in the ‘Overview’ of the task flow as bluish shade in the check box. No checkmark is set and a look into the source reveals that the whole section


is just missing from the XML file.

TaskFlow after creation

TaskFlow after creation

Once you click on this property in the property editor you can just switch between ‘isolated’ or ‘shared’.

TaskFlow properties (2)

TaskFlow properties (2)

The only possible way to get the bluish shade back is to delete the section in the source view of the task flow.

TaskFlow properties in 'Source Mode'

TaskFlow properties in ‘Source Mode’

So this checkbox has three states ‘bluish’, ‘isolated’, and ‘shared’. Well, there is a forth state which you get if you open the property editor in source mode and select ‘default’. The following table shown all states together with their meaning:

State  Meaning
Bluish  Shared
Check marked  Shared
Unchecked not bluish  Isolated
Data-control-scope empty  Isolated

While the application works according to the meaning of the flag, I find it not intuitive how JDev handles this setting. The programmer who made the change to the application clicked this property, but meant to do so on a different task flow. So he unchecked the ‘Share data controls with calling task flow’ property as he remembered that it was not set before.

My advise is to set the flag whenever you create a task flow so you know which share mode the task flow uses. This avoids errors like the one described in this blog.

In the meantime Chris Muir raised the issue with the UX specialists (Oracle intern) and Bug 14390576 has been raised for this issue.
Thank you Chris!

The sample uses the HR schema and was build with JDeveloper, tested with and . You can download the sample work space form ADF Samples: Source Code

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