8.6.5 Memory Only Storage for Form Page Items
The wizard creates the form region's page items with a Storage setting of Per Request (Memory Only).
This means the APEX engine does not save their values in user session state after page processing is complete. This is not required because this form page saves any changes submitted by the user to the EMP table before the dialog closes. A side-effect is that the form region's page item values always start out null when the page renders before any Pre-Rendering computations or page processes execute.
Figure 8-39 All Form Region Page Items Use "Memory Only" Storage
The figure below shows how the wizard configures the link target of the list page's (Create) button. Notice it passes no parameters to the target edit page.
Figure 8-40 List Page's (Create) Button Passes No Parameters to Edit Page
This explains why the form page opens with empty fields when they click on the list page's (Create) button. The button's link target passes no value for the primary key page item P4_EMPNO, and it is one of the form region's page items with Memory Only storage. When the Form - Initialization process executes in the Pre-Rendering phase, it performs no lookup and the Memory Only page items remain empty. This leaves the page ready for the end user to enter data for a new employee.
Parent topic: Studying a List and Edit Flow