Data validation at action invocation

The validate action attribute controls field validation when an action is fired.

When using the UNBUFFERED mode of interactive instructions such as INPUT or DIALOG, if the user triggers an action, the current field data is checked and loaded in the target variable bound to the form field. For example, if the user types a wrong date (or only a part of a date) in a field using a DATE variable and then clicks on a button to invoke an action, the runtime system will display an invalid input error and will not execute the ON ACTION block corresponding to the button.

To prevent data validation for some actions, use the VALIDATE action attribute.

The validate action attribute can be set in the global action default file, or at the form level, with the VALIDATE attribute in a line of the ACTION DEFAULTS section, and in the ATTRIBUTES() clause of the ON ACTION action handler.

This validate attribute instructs the runtime not to copy the input buffer text into the program variable (requiring input buffer text to match the target data type).

   ACTION undo ( TEXT="Undo", VALIDATE=NO )

This is especially needed in DIALOG instructions; in singular dialogs like INPUT, predefined actions like cancel do not validate the current field value when UNBUFFERED mode is used.