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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()

Description forthcoming.


Instance Methods



clone

public Object clone()

Conformance to Cloneable.

equals

public abstract boolean equals(Object anObject)

Description forthcoming.

hashCode

public abstract int hashCode()

Description forthcoming.

isTemporary

public boolean isTemporary()

Returns false. See the class description for more information.


Notifications


GlobalIDChangedNotification

public static final String GlobalIDChangedNotification

Posted whenever EOTemporaryGlobalIDs are replaced by permanent EOGlobalIDs. The notification contains:
Notification Object null
Userinfo A mapping from the temporary IDs (keys) to permanent IDs (values)


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


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