About Application Computations

A common use of an application item is to store the value of the last page viewed in the application. By storing the value in an item, you can add a back button and then redirect the user to the page number captured by the computation. This type of computation works well, for example, when you need to enable users to back out of an error page.

The following is an example of a computation that stores the last page visited. In this example, the computation:

• Stores the last application page visited to an item named LAST_PAGE

• Checks that the value of a CURRENT_PAGE_ITEM is of type PL/SQL Function Body with a Computation body of:

  BEGIN
     :LAST_PAGE := nvl(:CURRENT_PAGE,:APP_PAGE_ID);
     :CURRENT_PAGE := :APP_PAGE_ID;
     RETURN :LAST_PAGE;
  END;