EOGlobalID

Inherits from:

Object

Implements:

Cloneable

Serializable

Package:

com.webobjects.eocontrol

Class Description

An EOGlobalID is a compact, universal identifier for a persistent object, forming the basis for uniquing in Enterprise Objects Framework. An EOGlobalID uniquely identifies the same object or record both between EOEditingContexts in a single application and in multiple applications (as in distributed systems). EOGlobalID is an abstract class, declaring only the methods needed for identification. A concrete subclass must define appropriate storage for identifying values (such as primary keys), as well as an initialization or creation method to build IDs. See the EOKeyGlobalID class specification for an example of a concrete ID class.

Temporary Identifiers

EOEditingContexts and other object stores support the insertion of new objects without established IDs, creating temporary IDs that get replaced with permanent ones as soon as the new objects are saved to their persistent stores. The temporary IDs are instances of the EOTemporaryGlobalID class.

When an EOObjectStore saves these newly inserted objects, it must replace the temporary IDs with persistent ones. When it does this, it must post an GlobalIDChangedNotification announcing the change so that observers can update their accounts of which objects are identified by which global IDs. The notification's userInfo dictionary contains a mapping from the temporary IDs (the keys) to their permanent replacements (the values).

Constants

EOGlobalIDdefines String constants for the names of the notifications it posts. For more information, see the section "Notifications" (page 232) below.

Interfaces Implemented

Cloneable

clone

Constructors

EOGlobaIID

public EOGlobalID()

Instance Methods

clone

public Object clone()

equals

public abstract boolean equals(Object anObject)

hashCode

public abstract int hashCode()

isTemporary

public boolean isTemporary()

Notifications

GlobalIDChangedNotification

public static final String GlobalIDChangedNotification

© 2001 Apple Computer, Inc. (Last Published April 19, 2001)