Post-Form trigger in Oracle Forms fires during the Leave the Form process, when a form is exited.
You can use Post-Form trigger for the tasks such as: To clean up the form before exiting. For example, use a Post-Form trigger to erase any global variables that the form no longer requires. To display a message to the operator upon form exit etc.
This trigger does not fire when the form is exited abnormally, for example, if validation fails in the form and on failure processing halts.
Create the post-form trigger as shown in below screen shot:
Below is the example given for post-form trigger to ask the user on exit of the form that "Are you sure to Exit?" if user choose yes (alert_button1) then exit and if user choose No (alert_button2) then cancel the exiting of form.
if show_alert('conf_alert') = alert_button1 then
-- do nothing or perform any task on exiting such as log some data etc.
-- and form will exit.
-- this will cancel the forms exit execution.