Customizing field properties by using overlays
Unlike most overlay objects, a field overlay is not a copy of the field object. Instead, a field overlay is a subset of the field's properties.The field overlay and the origin field in the origin form share the same data.
A field overlay enables you to modify the field's database properties. You can modify the database properties such as Permissions, Default Value, Length, Associated Menu, Help Text, and Full Text MFS Category Name.
To change a field's layout or display properties, you do not need to create the field overlay. Instead, modify the overlay of its associated view and add the field to the view overlay. For more information about overlaying a form view, see Customizing display properties.
The other fields in the form view are not part of the view overlay and continue to retain the base properties. This functionality of view overlay is beneficial during upgrades. When you upgrade an application, the fields that are not included in a view overlay inherit the base properties. Customizations to fields are preserved during an upgrade.
Consider the example where a form contains a menu field. Because the menu is attached to a field, you must first overlay the form and then the field. You must also overlay all the views that contain that field.
The following actions affect all the views with which a field is associated:
- Adding an item to a selection field
- Adding a character menu to a field
- Adding columns to a table field
If you want to add any of these fields, you must overlay each of the views that contain these fields.