Oracle JHeadstart Developer's Guide - Downloads - Oracle

4.4.3. Groups
4.4.4. Items
4.4.5. Lists of Values
A service is made up of one or more groups. A group allows users to query and modify a
single data collection that maps to an ADF BC View Object (VO). Depending on the
layout options you choose, the group may be displayed on a single page or on a number
of related pages.
Groups may be nested to support parent-child relationships between their respective
View Objects.
Compared to a form module defined through Oracle Designer, you would typically
create one group for each first level module component. For detail module components
in a master-detail relationship, you would use nested groups.
A group consists of Items, Regions and Detail Groups. These concepts are discussed
below.
An item is a mapping to an attribute of an ADF View Object (which normally maps to a
database column). All kinds of properties can be set for an item. For instance you can
specify a default value or a label (used when generating prompts). An item can have a
List of Values, which is explained in the next section.
A List of Values (LOV) construction in an Application Definition links an item to a group
of type LOV, and specifies which items in the LOV group are to be mapped to which
items in the base group. This is required if in the generated application you want to
populate the item using a List of Values popup window instead of using a dropdown
list.
Example The EMPLOYEES table has a foreign key to the DEPARTMENTS table.
When adding an EMPLOYEE, you need to choose the department. Suppose you want to
enter the the department using a List of Values, and you want to put that LOV on
the Department Name instead of the Department Id.
In the Application Definition you then have to create an item DepartmentName
(after first creating it in the ADF BC View Object), and link an LOV to that item.
This is how it looks in the Application Definition editor:
4 - 12 Using the JHeadstart Addins JHeadstart Developer’s Guide