OAF: Issues associated with VO Substitution in Oracle Applications Framework - Part1

There are more and more questions coming in the OTN Forum with various issues with VO Substitution.

Most of these are related to one specific problem. I have initially posted a blog for a specific scenario 

OAF: Transient Attributes not getting populated in Extended VO

Some other scenarios :

• Able to change the values in the page, but after saving, the value is not getting changed in the database, but the screen shows  "Saved Successfully".
• Null pointer exception thrown in the VOHelper class associated with the Standard VORowImpl.

Reason:

After debugging the code we found that in all the cases the the VORowImpl generated by the Jdeveloper is modifed in the Standard VORowImpl. Oracle Product development team has modified the getter and setter methods of the attributes for achieving the specific functionality. Some cases they have also overridden the setAttributeInternal() method.

What happens is, when you create a extended VO in the Jdeveloper, it creates its own RowImpl. The setter and getter methods are the default methods. When you substitute the VO, the framework calls the extended VO's getters and setters. So the logic written inside the standard VO's gets ignored.

Solution:

To fix (to retain the standard functionality), you need to modify the getter and setter methods of those attributes which is affected. You can look into the standard VORowImpl to see which all attributes have additional logic added. For all those attributes, you need to call super.xxxx().

Modify the getter method of the extended VORowImpl like this:

 public String getAttribute1() {  
      //return (String) getAttributeInternal("Attribute1");  
      return super.getAttribute1();
 }  

Modify the setter method of the extended VORowImpl like this:

 public void setAttribute1(String value) {  
      //setAttributeInternal("Attribute1",value);  
      super.setAttribute1(value);
 }  

Note: There might be exceptions also.

Also refer:
OAF: Issues associated with VO Substitution in Oracle Applications Framework - Part2

Feel free to point out if anything is missing/wrong in this blog.