About On Demand Application Processes

A special type of application process is the On Demand process. An On Demand application process has a Process Point of On Demand and executes when called from a page-level On Demand process. On Demand processes are useful when you have PL/SQL logic that you would like to run from different execution points across multiple pages.

Running an On Demand Process from a Page Request

You can have a page request run an On Demand process by using the following syntax:

f?p=application_id:page_id:session:APPLICATION_PROCESS=process_id

Where:

application_id is the application ID or alphanumeric alias
page_id is the page number or alphanumeric alias
session is the session ID
APPLICATION_PROCESS=process_id is the keyword APPLICATION_PROCESS= followed by either the process ID or an alphanumeric name of an application-level process having a Process Point of On Demand

When you use this syntax, the Application Express engine recognizes the request and processes it using the following rules:

The page number in the URL can be any page number or alias. A page number or alias is required in the request only as a syntactic placeholder because no specific page is accessed for this type of request.
The process authorization scheme, the application's authorization scheme, and the process conditions are supported.
Session state (that is, item names and values) may be set in the URL, but clear cache options are ignored.
Any failures of authentication, authorization, or process conditions do not result in visible error messages or other indicators of such failures and most often result in a blank page being displayed.
Specifying the process by name locates the first process with the specified (case-preserved) name.