ON ACTION block
The ON ACTION action-name blocks execute a sequence of
instructions when the user triggers a specific action.
A typical action handler block looks like this:
ON ACTION action-name
instruction
...Action blocks are bound by name to action views (like buttons) in the current form. Action views
can be BUTTON, TOOLBAR buttons, or TOPMENU
options, and if no explicit action view is defined, actions are rendered with a default action view,
depending on the type of front-end.
This example defines an action block to open a typical zoom window and let the user select a
customer
record:
ON ACTION zoom
CALL zoom_customers() RETURNING st, rec.cust_id, rec.cust_name In a dialog handling user input such as
INPUT, INPUT ARRAY
and CONSTRUCT, if an action is
specific to a field, add the INFIELD clause to have the action automatically
enabled when the corresponding field gets the
focus: ON ACTION zoom INFIELD cust_city
CALL zoom_cities() RETURN st, rec.cust_city In most cases actions are decorated with action defaults in form files, but there can be cases
where the
ON ACTION handler needs to define its own attributes at the program
level. This can be done by adding the ATTRIBUTES() clause of
ON
ACTION: ON ACTION custinfo ATTRIBUTES(DISCLOSUREINDICATOR, IMAGE="info")
CALL show_customer_info() For more details about action handlers, and action configuration, see Dialog actions.