RKRelationshipMapping Class Reference
Inherits from | RKPropertyMapping : NSObject |
Declared in | RKRelationshipMapping.h |
Overview
The RKRelationshipMapping
class is used to describe relationships of a class in an RKObjectMapping
or an entity in an RKEntityMapping
object.
RKRelationshipMapping
extends RKPropertyMapping
to describe features specific to relationships, including the RKMapping
object describing how to map the destination object.
Tasks
Creating a Relationship Mapping
-
+ relationshipMappingFromKeyPath:toKeyPath:withMapping:
Creates and returns a new relationship mapping object describing how to transform a related object representation at
sourceKeyPath
to a new representation atdestinationKeyPath
using the given mapping.
Accessing the Destination Mapping
Properties
mapping
An RKMapping
object describing how to map the object representation at sourceKeyPath
to a new represenation at destinationKeyPath
.
@property (nonatomic, strong, readonly) RKMapping *mapping
Declared In
RKRelationshipMapping.h
Class Methods
relationshipMappingFromKeyPath:toKeyPath:withMapping:
Creates and returns a new relationship mapping object describing how to transform a related object representation at sourceKeyPath
to a new representation at destinationKeyPath
using the given mapping.
+ (RKRelationshipMapping *)relationshipMappingFromKeyPath:(NSString *)sourceKeyPath toKeyPath:(NSString *)destinationKeyPath withMapping:(RKMapping *)mapping
Parameters
- sourceKeyPath
A key path from which to retrieve data in the source object representation that is to be mapped as a relationship.
- destinationKeyPath
The key path on the destination object to set the object mapped results.
- mapping
A mapping object describing how to map the data retrieved from
sourceKeyPath
that is to be set ondestinationKeyPath
.
Discussion
The mapping may describe a to-one or a to-many relationship. The appropriate handling of the source representation is deferred until run-time and is determined by performing reflection on the data retrieved from the source object representation by sending a valueForKeyPath:
message where the key path is the value given in sourceKeyPath
. If an NSArray
, NSSet
or NSOrderedSet
object is returned, the related object representation is processed as a to-many collection. Otherwise the representation is considered to be a to-one.
Declared In
RKRelationshipMapping.h