Oracle Tips by Burleson
Often when creating application pages, the wizard
will be used to quickly create a form region on a page. However, most
pages have more than one region on a page, and therefore creating
other processes manually to deal with the other regions is needed. It
may be a process that executes in the before region processing point
for populating the page, or in the after submit processing point to
update the database.
The exercise shown below follows the idea that an
additional region on an application page has been created and some
page items, to display a persons name and address, were added. The
process to create will be a Before Regions process used to populate
the page items. The same process would be followed for creating a
process that would execute in the After Submit process point.
Creating processes is done from the page
Click on the <![if !vml]><![endif]> in
the Processes area under Page Rendering.
On the Process Type page, select the process type and
click Next. This example chose the PL/SQL option.
On the Process Attributes page:
Enter a Name for the process: Populate
Enter the Sequence in which it should execute
the process point selected. For this example, it will be sequence
Select the Process Point: On Load - Before
On the Process page, enter the SQL code necessary for the
process and click Next. The code used to populate the example
page items is shown here.
first_name, last_name, address_id
:P100_FIRST_NAME, :P100_LAST_NAME, :P100_ADDRESS_ID
employee_id = :P100_EMPLOYEE_ID;
address_id = :P100_ADDRESS_ID;
On the Messages page:
Enter a Success Message if desired: Success
messages are not commonly used in page population processes, but
they are available.
Enter a Failure Message if desired: In the
event there is an error, this message will be displayed to the
user. It will be the same message regardless of where in the
process the error occurred. For advanced programming I have seen
the failure message not used, and the programmers often use
raise_application_error in-line with the SQL code for the process,
especially if there are multiple statements written in the
On the Process Conditions page, the conditions under which this
process should execute can be entered. For example, the developer may
only want this process to fire if the value of P100_EMPLOYEE_ID is NOT
Click the Create Process button to complete the wizard.
Creating the other types of processes is similar.
Use the notes in the rest of the chapter to understand each type of
process and the various attributes that need to be set for them.
The above book excerpt is from:
HTML-DB Oracle Application Express
Dynamic Web Pages with OAE
Michael Cunningham & Kent