Files
RestKit/Code/ObjectMapping/RKMappingOperation.h
2012-09-20 19:11:38 -04:00

162 lines
7.3 KiB
Objective-C

//
// RKMappingOperation.h
// RestKit
//
// Created by Blake Watters on 4/30/11.
// Copyright (c) 2009-2012 RestKit. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#import "RKObjectMapping.h"
#import "RKAttributeMapping.h"
@class RKMappingOperation, RKDynamicMapping;
@protocol RKMappingOperationDataSource;
/**
Objects acting as the delegate for `RKMappingOperation` objects must adopt the `RKMappingOperationDelegate` protocol. These methods enable the delegate to be notified of events such as the application of attribute and relationship mappings during a mapping operation.
*/
@protocol RKMappingOperationDelegate <NSObject>
@optional
/**
Tells the delegate that an attribute or relationship mapping was found for a given key path within the data being mapped.
@param operation The object mapping operation being performed.
@param mapping The `RKAttributeMapping` or `RKRelationshipMapping` found for the key path.
@param keyPath The key path in the source object for which the mapping is to be applied.
*/
- (void)mappingOperation:(RKMappingOperation *)operation didFindMapping:(RKPropertyMapping *)mapping forKeyPath:(NSString *)keyPath;
// TODO: mappingOperation: willMapKeyPath: usingMapping: ???
/**
Tells the delegate that no attribute or relationships mapping was found for a given key path within the data being mapped.
@param operation The object mapping operation being performed.
@param keyPath The key path in the source object for which no mapping was found.
*/
- (void)mappingOperation:(RKMappingOperation *)operation didNotFindMappingForKeyPath:(NSString *)keyPath;
/**
Tells the delegate that the mapping operation has set a value for a given key path with an attribute or relationship mapping.
@param operation The object mapping operation being performed.
@param value A new value that was set on the destination object.
@param keyPath The key path in the destination object for which a new value has been set.
@param propertyMapping The RKAttributeMapping or RKRelationshipMapping found for the key path.
*/
- (void)mappingOperation:(RKMappingOperation *)operation didSetValue:(id)value forKeyPath:(NSString *)keyPath usingMapping:(RKPropertyMapping *)propertyMapping;
/**
Tells the delegate that the mapping operation has declined to set a value for a given key path because the value has not changed.
@param operation The object mapping operation being performed.
@param value A unchanged value for the key path in the destination object.
@param keyPath The key path in the destination object for which a unchanged value was not set.
@param propertyMapping The RKAttributeMapping or RKRelationshipMapping found for the key path.
*/
- (void)mappingOperation:(RKMappingOperation *)operation didNotSetUnchangedValue:(id)value forKeyPath:(NSString *)keyPath usingMapping:(RKPropertyMapping *)propertyMapping;
/**
Tells the delegate that the mapping operation has failed due to an error.
@param operation The object mapping operation that has failed.
@param error An error object indicating the reason for the failure.
*/
- (void)mappingOperation:(RKMappingOperation *)operation didFailWithError:(NSError *)error;
/**
Tells the delegate that the mapping operation has selected a concrete object mapping with which to map the source object.
Only sent if the receiver was initialized with an instance of RKDynamicMapping as the mapping.
@param operation The mapping operation.
@param objectMapping The concrete object mapping with which to perform the mapping.
@param dynamicMapping The dynamic source mapping from which the object mapping was determined.
*/
- (void)mappingOperation:(RKMappingOperation *)operation didSelectObjectMapping:(RKObjectMapping *)objectMapping forDynamicMapping:(RKDynamicMapping *)dynamicMapping;
@end
/**
Instances of `RKMappingOperation` perform transformation between object representations according to the rules expressed in `RKObjectMapping` objects. Mapping operations provide the foundation for the RestKit object mapping engine and perform the work of inspecting the attributes and relationships of a source object and determining how to map them into new representations on a destination object.
*/
@interface RKMappingOperation : NSObject
///---------------------------------------
/// @name Initializing a Mapping Operation
///---------------------------------------
/**
Initializes the receiver with a source object, a destination object and an object mapping with which to perform an object mapping.
@param sourceObject The source object to be mapped. Cannot be `nil`.
@param destinationObject The destination object the results are to be mapped onto. May be `nil`, in which case a new object target object will be obtained from the `dataSource`.
@param objectOrDynamicMapping An instance of `RKObjectMapping` or `RKDynamicMapping` defining how the mapping is to be performed.
@return The receiver, initialized with a source object, a destination object, and a mapping.
*/
- (id)initWithSourceObject:(id)sourceObject destinationObject:(id)destinationObject mapping:(RKMapping *)objectOrDynamicMapping;
///--------------------------------------
/// @name Accessing Mapping Configuration
///--------------------------------------
/**
A dictionary of mappable elements containing simple values or nested object structures.
*/
@property (nonatomic, strong, readonly) id sourceObject;
/**
The target object for this operation. Mappable values in elements will be applied to object using key-value coding.
*/
@property (nonatomic, strong, readonly) id destinationObject;
/**
The mapping defining how values contained in the source object should be transformed to the destination object via key-value coding.
Will either be an instance of `RKObjectMapping` or `RKDynamicMapping`.
*/
@property (nonatomic, strong, readonly) RKMapping *mapping;
///-------------------------------------------
/// @name Configuring Delegate and Data Source
///-------------------------------------------
/**
The delegate to inform of interesting events during the mapping operation lifecycle.
*/
@property (nonatomic, weak) id<RKMappingOperationDelegate> delegate;
/**
The data source is responsible for providing the mapping operation with an appropriate target object for mapping when the `destinationObject` is `nil`.
@see `RKMappingOperationDataSource`
*/
@property (nonatomic, weak) id<RKMappingOperationDataSource> dataSource;
///-------------------------
/// @name Performing Mapping
///-------------------------
/**
Process all mappable values from the mappable dictionary and assign them to the target object according to the rules expressed in the object mapping definition
@param error A pointer to an `NSError` reference to capture any error that occurs during the mapping. May be `nil`.
@return A Boolean value indicating if the mapping operation was successful.
*/
- (BOOL)performMapping:(NSError **)error;
@end