Determining the Fields to Expose in Component Interfaces

You expose fields from a component in the component interface by dragging a record field or a scroll from the component view into the component interface view. However, some forethought is required before exposing a component as a component interface. You need to have a thorough understanding of the underlying component so that you expose fields that are required in the external system. For example, if the component has a field called SSN, you need to be sure that the SSN field is required before exposing it to the external system. Expose only those properties that are necessary.

The component view displays fields that are available in the component buffer at runtime. For example, if a record containing 10 fields has only 3 fields included on a page, then the component view will list only those 3 fields.

The first time that you drag a scroll from the component view to the component interface view, the system uses the following rules to determine what properties to expose:

• Keys are exposed only at the highest-level collection in which they first appear.

  In some cases, this is not appropriate. When an effective-dated component that has the same level-zero and level-one record is exposed through a component interface, it should be exposed the same way in which it appears on a page in the component. In this case, only one key field typically appears at level zero and the effective-date keys appear at level one. The component interface wrapper should expose the page in the same fashion—removing keys that do not appear in the level-zero scroll from the component interface top-level collection and manually adding keys that appear in level-one scroll to the second-level collection.

  Typically, you do not want to expose Get keys or Create keys as properties, because these are set before a Get or Create operation and might be inadvertently changed.

• Make sure that you do not delete all the properties within the collection; that would result in an empty collection. If such empty collections exist, remove them; otherwise, they appear with X in the component interface view.

• If your page does not support Add mode, then you should not expose the level-zero record of the component, because it contains data that is not specific to the component interface that you are creating.

• Do not expose fields that are not visible in the component view.

  The component optimization code might eliminate unused fields from its buffers, which results in an error when that field is accessed by the component interface.