Skip to main content

Posts

Showing posts from July, 2009

Programmatically publishing Contextual Events

ADF task flows provide modularity to the web applications. Bounded task flows are really useful while realizing business use cases, which may repeats across application(s). Please refer Fusion Developer's Guide if you want to know more about this topic. Bounded task flows are added to the page as regions. It is very common that one region may need to communicate with other regions. This is accomplished by Contextual Events. To know more about Contextual Events, please refer Creating Contextual Events.

There are scenarios where task flows may need to raise the Contextual Events based on complex business conditions. Declarative event handling mechanism might not be sufficient in this case. Now the question is how to raise 'Contextual Events' programmatically from backing bean? Let me try summarizing the steps below. Please refer the Fusion Developer's Guide for detailed explanation on creation of Contextual Event.

1. Create the Producer (Payload) Method
2. Bind the Producer…

Target Unreachable, identifier row resolved to null !

SEVERE: Server Exception during PPR, #1
javax.el.PropertyNotFoundException: Target Unreachable, identifier 'row' resolved to null
at com.sun.el.parser.AstValue.getTarget(AstValue.java:xx)
at com.sun.el.parser.AstValue.isReadOnly(AstValue.java:xxx)
at com.sun.el.ValueExpressionImpl.isReadOnly(ValueExpressionImpl.java:xxx)
at



Have you ever seen the above exception while running the web application built on ADF? Apparently, this exception doesn’t communicate much on the root cause and noticed that developers search in dark to find a solution.

This article discusses couple of possible reasons for this error.

Incorrect Key definition for ViewOject

Consider the classic Employee - Department example.
Below diagram shows the association between Employee and Department .



Please note that Emp has Empno as Primary Key(PK) defined and Dept has Deptno as Primary Key.

Let us try visualizing User Interface for Employee. An Employee can belong to a specific Department. So let us try defining a Lis…