|Oracle Workflow Developer's Guide|
Part Number B10284-02
If your item type has or will have more than one runnable process activity associated with it, define a PL/SQL function that determines which process activity to run in a particular situation. For example, you may have two different requisition approval process activities associated with the same item type. The process that Oracle Workflow executes may vary depending on how and where the requisition originates. Your selector function would determine which process would be appropriate in any given situation.
You can also extend the Selector function to be a general callback function so that item type context information can be reset as needed if the SQL session is interrupted during the execution of a process. This is particularly important in the Oracle Applications scenario when you view a notification from the Notification Details web page and attempt to launch another form that is associated with the notification. Oracle Workflow calls the selector/callback function for your item type in 'TEST_CTX' mode to test the Oracle Applications context before turning the form launch over to the Oracle Application Object Library function security system. In 'TEST_CTX' mode, the selector/callback function can perform whatever logic necessary to determine whether it is appropriate to launch the form. See: Standard API for an Item Type Selector or Callback Function.