com.webobjects.eocontrol
Class EODetailDataSource

java.lang.Object
  com.webobjects.eocontrol.EODataSource
      com.webobjects.eocontrol.EODetailDataSource

All Implemented Interfaces:

EOKeyValueArchiving, Serializable

public class EODetailDataSource

extends EODataSource

implements Serializable, EOKeyValueArchiving

EODetailDataSource defines a data source for use in master-detail configurations, where operations in the detail data source are applied directly to properties of a master object. EODetailDataSource implements the standard fetchObjects, insertObject, and deleteObject methods to operate on a relationship property of its master object. It works for any concrete subclass of EODataSource, including another EODetailDataSource in a chain of master and detail data sources.

To set up an EODetailDataSource programmatically, you can typically create it by sending a dataSourceQualifiedByKey message to the master data source, then establish the master object with a qualifyWithRelationshipKey message. The latter method records the name of a relationship for a particular object to resolve in fetchObjects and to modify in insertObject and deleteObject. These three methods then manipulate the relationship property of the master object to perform the operations requested.

See Also:

fetchObjects(), insertObject(Object anObject), deleteObject(Object anObject), qualifyWithRelationshipKey(String relationshipKey, Object masterObject), Serialized Form

Nested Class Summary

Nested classes inherited from class com.webobjects.eocontrol.EOKeyValueArchiving

EOKeyValueArchiving.Awaking, EOKeyValueArchiving.FinishInitialization, EOKeyValueArchiving.Support

Constructor Summary

EODetailDataSource(EOClassDescription masterClassDescription, String key)
Creates and returns a new EODetailDataSource object.

EODetailDataSource(EODataSource masterDataSource, String key)
Creates and returns a new EODetailDataSource object.

Method Summary

EOClassDescription	classDescriptionForObjects() Returns the class description for the detail object if a detail key is defined, otherwise returns the master class description
EODataSource	dataSourceQualifiedByKey(String key) Creates an EODetailDataSource for key.
static Object	decodeWithKeyValueUnarchiver(EOKeyValueUnarchiver unarchiver) Provides conformance to EOKeyValueArchiving.
void	deleteObject(Object eo) Sends a removeObjectFromBothSidesOfRelationshipWithKey message to the master object using detailKey.
String	detailKey() Gets the detail key of the receiver, which names the relationship for which the receiver provides objects to its master object.
EOEditingContext	editingContext() Returns the editing context of the master data source, or null if there is not one
void	encodeWithKeyValueArchiver(EOKeyValueArchiver archiver) Provides conformance to EOKeyValueArchiving.
NSArray	fetchObjects() Sends valueForKey (defined in the NSKeyValueCoding interface) to the master object with the receiver's detail key as the argument, constructs an array for the returned object or objects, and returns it.
void	insertObject(Object eo) Sends an addObjectToBothSidesOfRelationshipWithKey message to the master object.
EOClassDescription	masterClassDescription() Gets the EOClassDescription for the receiver's master object.
EODataSource	masterDataSource() Gets the master data source for the receiver.
Object	masterObject() Returns the master object of the receiver.
void	qualifyWithRelationshipKey(String key, Object sourceObject) Configures the receiver to provide objects based on the relationship of sourceObject named by key.
void	setDetailKey(String detailKeyPath) Sets the detail key of the receiver, which names the relationship for which the receiver provides objects to its master object.
void	setMasterClassDescription(EOClassDescription master) Assigns master as the EOClassDescription for the receiver's master object.

Methods inherited from class com.webobjects.eocontrol.EODataSource

createObject

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EODetailDataSource

public EODetailDataSource(EOClassDescription masterClassDescription,
                          String key)

Creates and returns a new EODetailDataSource object. The new data source's masterObject is associated with masterClassDescription, and key is assigned to the new data source's detailKey. The constructor invokes qualifyWithRelationshipKey specifying key as the relationship key and null as the object.

Parameters:

masterClassDescription - class description for the master object

key - keypath defining relationship on the master object

See Also:

masterObject(), detailKey(), qualifyWithRelationshipKey( String relationshipKey , Object masterObject), masterClassDescription()

EODetailDataSource

public EODetailDataSource(EODataSource masterDataSource,
                          String key)

Creates and returns a new EODetailDataSource object. The new data source provides destination objects for the relationship named by a key from a masterObject in masterDataSource.

Parameters:

masterDataSource - provider of the master objects

key - the String giving the new relationship

See Also:

masterDataSource()

Method Detail

classDescriptionForObjects

public EOClassDescription classDescriptionForObjects()

Returns the class description for the detail object if a detail key is defined, otherwise returns the master class description

Overrides:

classDescriptionForObjects in class EODataSource

Returns:

EOClassDescription for the type of objects managed by the data source

dataSourceQualifiedByKey

public EODataSource dataSourceQualifiedByKey(String key)

Creates an EODetailDataSource for key.

Specified by:

dataSourceQualifiedByKey in class EODataSource

Parameters:

key - relationship key that is the destination object of the relationship

Returns:

detailed EODataSource that provides the destination objects of the relationship

See Also:

EODataSource.qualifyWithRelationshipKey(String key, Object sourceObject)

decodeWithKeyValueUnarchiver

public static Object decodeWithKeyValueUnarchiver(EOKeyValueUnarchiver unarchiver)

Provides conformance to EOKeyValueArchiving.

Parameters:

unarchiver -

Returns:

decoded object from the archive

deleteObject

public void deleteObject(Object eo)

Sends a removeObjectFromBothSidesOfRelationshipWithKey message to the master object using detailKey. Throws an IllegalStateException if there is no master object or no detail key set.

Specified by:

deleteObject in class EODataSource

Parameters:

eo - object to be deleted

Throws:

exception - if there's no master object or no detail key set

detailKey

public String detailKey()

Gets the detail key of the receiver, which names the relationship for which the receiver provides objects to its master object.

Returns:

name of the relationship for which the receiver provides objects; null if it has not been set yet

See Also:

qualifyWithRelationshipKey(String relationshipKey, Object masterObject)

editingContext

public EOEditingContext editingContext()

Returns the editing context of the master data source, or null if there is not one

Overrides:

editingContext in class EODataSource

Returns:

the EOEditingContext of the master object or its data source

encodeWithKeyValueArchiver

public void encodeWithKeyValueArchiver(EOKeyValueArchiver archiver)

Provides conformance to EOKeyValueArchiving.

Specified by:

encodeWithKeyValueArchiver in interface EOKeyValueArchiving

Parameters:

archiver -

See Also:

EOKeyValueArchiver

fetchObjects

public NSArray fetchObjects()

Sends valueForKey (defined in the NSKeyValueCoding interface) to the master object with the receiver's detail key as the argument, constructs an array for the returned object or objects, and returns it. Returns an empty array if there's no master object, or returns an array containing the master object itself if no detail key is set.

Overrides:

fetchObjects in class EODataSource

Returns:

an immutable array containing objects in the detail relationship, the master object if no relationship is defined, or the empty array

insertObject

public void insertObject(Object eo)

Sends an addObjectToBothSidesOfRelationshipWithKey message to the master object.

Specified by:

insertObject in class EODataSource

Parameters:

eo - object to be inserted

Throws:

exception - if there's no master object or no detail keyset

masterClassDescription

public EOClassDescription masterClassDescription()

Gets the EOClassDescription for the receiver's master object.

Returns:

EOClassDescription of the receiver's master object

See Also:

setMasterClassDescription(EOClassDescription master), EODetailDataSource(EOClassDescription masterClassDescription, String key)

masterDataSource

public EODataSource masterDataSource()

Gets the master data source for the receiver.

Returns:

receiver's master data source

See Also:

detailKey(), EODetailDataSource(EOClassDescription masterClassDescription, String key)

masterObject

public Object masterObject()

Returns the master object of the receiver.

Returns:

object in the master data source for which the receiver provides objects

See Also:

detailKey(), qualifyWithRelationshipKey( String relationshipKey, Object masterObject)

qualifyWithRelationshipKey

public void qualifyWithRelationshipKey(String key,
                                       Object sourceObject)

Configures the receiver to provide objects based on the relationship of sourceObject named by key. Relationship key can be different from the one provided to the constructor, which changes the relationship the receiver operates on. If sourceObject is null this method causes the receiver to return an empty array when sent a fetchObjects message.

Specified by:

qualifyWithRelationshipKey in class EODataSource

Parameters:

key - relationship key

sourceObject - the source object

See Also:

fetchObjects(), detailKey()

setDetailKey

public void setDetailKey(String detailKeyPath)

Sets the detail key of the receiver, which names the relationship for which the receiver provides objects to its master object.

Parameters:

detailKeyPath - used to qualify the master-detail relationship of the datasource

setMasterClassDescription

public void setMasterClassDescription(EOClassDescription master)

Assigns master as the EOClassDescription for the receiver's master object.

Parameters:

master - EOClassDescription for the receiver's master object

See Also:

masterClassDescription()