PATH Documentation > WebObjects 4.5 > EOControl Reference

EODetailDataSource

Inherits from:
(com.apple.client.eocontrol) EODataSource : Object
(com.apple.yellow.eocontrol) EODataSource : NSObject

Package:
com.apple.client.eocontrol

com.apple.yellow.eocontrol

Class Description

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, so it works for any concrete subclass of EODataSource, including another EODetailDataSource (for a chain of three master and detail data sources).

To set up an EODetailDataSource programmatically, you 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 the individual method descriptions for more information.

Method Types

Constructors

EODetailDataSource

Qualifying instances

qualifyWithRelationshipKey

Examining instances

masterDataSource

detailKey

masterObject

Accessing the master class description

masterClassDescription

setMasterClassDescription (com.apple.yellow.eocontrol only)

Accessing the objects

fetchObjects

Inserting and deleting objects

insertObject

deleteObject

Accessing the master editing context

editingContext

Constructors

EODetailDataSource

public EODetailDataSource( EOClassDescription masterClassDescription, String relationshipKey)

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

See Also: masterClassDescription

public EODetailDataSource( EODataSource masterDataSource, String relationshipKey)

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

See Also: masterDataSource

Instance Methods

deleteObject

public void deleteObject(Object anObject)

Sends a removeObjectFromPropertyWithKey message (defined in the EORelationshipManipulation interface) to the master object with anObject and the receiver's detail key as the arguments. Throws an exception if there's no master object or no detail key set.

detailKey

public String detailKey()

Returns the name of the relationship for which the receiver provides objects, as provided to the constructor when the receiver was created or as set in qualifyWithRelationshipKey. If none has been set yet, returns null.

editingContext

public EOEditingContext editingContext()

Returns the EOEditingContext of the master object, or null if there isn't one.

fetchObjects

public NSArray fetchObjects()

Sends valueForKey (defined in the EOKeyValueCoding 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.

insertObject

public void insertObject(Object anObject)

Sends an addObjectToBothSidesOfRelationshipWithKey message (defined in the EORelationshipManipulation interface) to the master object with anObject and the receiver's detail key as the arguments. Throws an exception if there's no master object or no detail key set.

masterClassDescription

public EOClassDescription masterClassDescription()

Returns the EOClassDescription of the receiver's master object.

See Also: setMasterClassDescription, EODetailDataSource constructor

masterDataSource

public EODataSource masterDataSource()

Returns the receiver's master data source.

See Also: detailKey, EODetailDataSource constructor

masterObject

public Object masterObject()

Returns the object in the master data source for which the receiver provides objects. You can change this with a qualifyWithRelationshipKey message.

See Also: detailKey

`qualifyWithRelationshipKey`

public void qualifyWithRelationshipKey( String relationshipKey, Object masterObject)

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

See Also: detailKey

setMasterClassDescription

public void setMasterClassDescription(EOClassDescription classDescription)

(com.apple.yellow.eocontrol only) Assigns classDescription as the EOClassDescription for the receiver's master object.

See Also: masterClassDescription