The REQUEST feature

This is an APEX built-in feature that helps us to determine if, or which button, has been activated (pressed).

Each time we press a button, and this button initializes a page submit process, the APEX engine sets the value of REQUEST to the Name of the button, or to the value of the Request field in case this is a button displayed among items.

We can also manually set the REQUEST value, either declaratively as part of a page branch, or by using the fourth segment of the f?p URL notation.

The REQUEST scope

Submitting the page initiates the page ACCEPT process, which includes several activities (as can be seen in the Page Processing column) such as Validations, Computations, Processes, and Branches. The REQUEST value is retained throughout the ACCEPT process and can be referenced in each of its activities. By default, the REQUEST value is cleared set to NULL with every branch to a new page (or self-branching).

If we manually set the REQUEST value as part of a page branch...