Field hooks

A field hook is useful for an event that affects a particular field within the record. A field hook can set an initial value, respond to events when a field value changes, enforce access permissions that permit only the user groups that you specify to change field values, and validate the values that users provide.

The scope of a field hook is the current field within the current record. The following types of field hooks are supported:

Field hook

Description

Choice List

Returns a set of valid values. Use this hook with fields that are displayed using a list-type control, such as a list box or combo box. You can also provide values without scripting by using a constant or a dynamic list. See Creating a choice list for a field .

Default Value

Sets the initial value of the field. This hook is called at the beginning of a Submit action. You can write a default-value hook with a script subroutine. You can also assign a constant value as the default value.

Permission

Returns one of the BehaviorType constants that indicates the user's access to the field. Use this hook to force workflow and/or security. (See the IBM Rational ClearQuest API Reference for enumerated constants.) If you add a Permission hook to a field, you must modify the Behaviors grid so that at least one field behavior is set to USE_HOOK. Failure to do this causes a validation error.

Validation

Validates the contents of the field. This hook is called when the value changes, to provide the user with immediate feedback about the validity of the field contents before committing the record to the database.

Value Changed

Responds to changes in the value of a field. Use this hook to update other fields (for example, dependent lists). After this hook runs, any field that the script has modified is validated by calling the Validation hook (if any) for the field.

Hooks are run according to the rules specified in Execution order of field and action hooks.