Maintaining Application Components › Maintaining Lists

Maintaining Lists

This section describes the Common Application Services (CAS) List facility and how to create and maintain list definitions.

Lists are defined and then stored on a database. They can be recalled to display a series of items as required on a panel. These items are typically objects and are identified with a series of attributes that relate to the object. For example, they may be identified with the object's identifier and description.

The list facility provides a generalized method for displaying and allowing selection of list items. The same list definition can be used to display the following lists:

• Action List

  Displays a series of objects against which actions can be applied

• Single Select

  Displays a series of items from which one is selected

• Multiple Select

  Displays a series of items from which one or more are selected

• Numbered List

  Displays a series of items that are numbered—an item is selected by entering its corresponding number

The type of list that is created from a list definition is determined by the call to $CACALL, the CAS interface.

To create a list, specify a list definition. A list definition comprises the following:

• Identifying information about the list and a specification of its behavior
• The source of the data to be displayed on the list
• A service procedure that is used to retrieve items to be included in the list
• A criteria definition to be used to determine an item's eligibility for inclusion on the list
• A sort expression to determine how items in the list are sorted
• Line entry presentation attributes that let you highlight specific records in a list based on a condition that you specify
• The format of the list