Files
RestKit/Code/Network/RKManagedObjectRequestOperation.m
2012-12-26 19:17:05 -05:00

506 lines
22 KiB
Objective-C

//
// RKManagedObjectRequestOperation.m
// RestKit
//
// Created by Blake Watters on 8/9/12.
// Copyright (c) 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 "RKManagedObjectRequestOperation.h"
#import "RKLog.h"
#import "RKHTTPUtilities.h"
#import "RKResponseMapperOperation.h"
#import "RKRequestOperationSubclass.h"
#import "NSManagedObjectContext+RKAdditions.h"
// Graph visitor
#import "RKResponseDescriptor.h"
#import "RKEntityMapping.h"
#import "RKDynamicMapping.h"
#import "RKRelationshipMapping.h"
// Set Logging Component
#undef RKLogComponent
#define RKLogComponent RKlcl_cRestKitCoreData
@interface RKNestedManagedObjectKeyPathMappingGraphVisitor : NSObject
@property (nonatomic, readonly) NSSet *keyPaths;
- (id)initWithResponseDescriptors:(NSArray *)responseDescriptors;
@end
@interface RKNestedManagedObjectKeyPathMappingGraphVisitor ()
@property (nonatomic, strong) NSMutableSet *mutableKeyPaths;
@end
@implementation RKNestedManagedObjectKeyPathMappingGraphVisitor
- (id)initWithResponseDescriptors:(NSArray *)responseDescriptors
{
self = [self init];
if (self) {
self.mutableKeyPaths = [NSMutableSet set];
for (RKResponseDescriptor *responseDescriptor in responseDescriptors) {
[self visitMapping:responseDescriptor.mapping atKeyPath:responseDescriptor.keyPath];
}
}
return self;
}
- (NSSet *)keyPaths
{
return self.mutableKeyPaths;
}
- (void)visitMapping:(RKMapping *)mapping atKeyPath:(NSString *)keyPath
{
id actualKeyPath = keyPath ?: [NSNull null];
if ([self.keyPaths containsObject:actualKeyPath]) return;
if ([mapping isKindOfClass:[RKEntityMapping class]]) [self.mutableKeyPaths addObject:actualKeyPath];
if ([mapping isKindOfClass:[RKDynamicMapping class]]) {
RKDynamicMapping *dynamicMapping = (RKDynamicMapping *)mapping;
for (RKMapping *nestedMapping in dynamicMapping.objectMappings) {
[self visitMapping:nestedMapping atKeyPath:keyPath];
}
} else if ([mapping isKindOfClass:[RKObjectMapping class]]) {
RKObjectMapping *objectMapping = (RKObjectMapping *)mapping;
for (RKRelationshipMapping *relationshipMapping in objectMapping.relationshipMappings) {
NSString *nestedKeyPath = keyPath ? [@[ keyPath, relationshipMapping.destinationKeyPath ] componentsJoinedByString:@"."] : relationshipMapping.destinationKeyPath;
[self visitMapping:relationshipMapping.mapping atKeyPath:nestedKeyPath];
}
}
}
@end
NSArray *RKArrayOfFetchRequestFromBlocksWithURL(NSArray *fetchRequestBlocks, NSURL *URL)
{
NSMutableArray *fetchRequests = [NSMutableArray array];
NSFetchRequest *fetchRequest = nil;
for (RKFetchRequestBlock block in [fetchRequestBlocks reverseObjectEnumerator]) {
fetchRequest = block(URL);
if (fetchRequest) [fetchRequests addObject:fetchRequest];
}
return fetchRequests;
}
/**
Returns the set of keys containing the outermost nesting keypath for all children.
For example, given a set containing: 'this', 'this.that', 'another.one.test', 'another.two.test', 'another.one.test.nested'
would return: 'this, 'another.one', 'another.two'
*/
NSSet *RKSetByRemovingSubkeypathsFromSet(NSSet *setOfKeyPaths);
NSSet *RKSetByRemovingSubkeypathsFromSet(NSSet *setOfKeyPaths)
{
return [setOfKeyPaths objectsPassingTest:^BOOL(NSString *keyPath, BOOL *stop) {
if ([keyPath isEqual:[NSNull null]]) return YES; // Special case the root key path
NSArray *keyPathComponents = [keyPath componentsSeparatedByString:@"."];
NSMutableSet *parentKeyPaths = [NSMutableSet set];
for (NSUInteger index = 0; index < [keyPathComponents count] - 1; index++) {
[parentKeyPaths addObject:[[keyPathComponents subarrayWithRange:NSMakeRange(0, index + 1)] componentsJoinedByString:@"."]];
}
for (NSString *parentKeyPath in parentKeyPaths) {
if ([setOfKeyPaths containsObject:parentKeyPath]) return NO;
}
return YES;
}];
}
// When we map the root object, it is returned under the key `[NSNull null]`
static id RKMappedValueForKeyPathInDictionary(NSString *keyPath, NSDictionary *dictionary)
{
return ([keyPath isEqual:[NSNull null]]) ? [dictionary objectForKey:[NSNull null]] : [dictionary valueForKeyPath:keyPath];
}
static void RKSetMappedValueForKeyPathInDictionary(id value, NSString *keyPath, NSMutableDictionary *dictionary)
{
NSCParameterAssert(value);
NSCParameterAssert(keyPath);
NSCParameterAssert(dictionary);
[keyPath isEqual:[NSNull null]] ? [dictionary setObject:value forKey:keyPath] : [dictionary setValue:value forKeyPath:keyPath];
}
// Precondition: Must be called from within the correct context
static NSManagedObject *RKRefetchManagedObjectInContext(NSManagedObject *managedObject, NSManagedObjectContext *managedObjectContext)
{
NSManagedObjectID *managedObjectID = [managedObject objectID];
if (! [managedObject managedObjectContext]) return nil; // Object has been deleted
if ([managedObjectID isTemporaryID]) {
RKLogWarning(@"Unable to refetch managed object %@: the object has a temporary managed object ID.", managedObject);
return managedObject;
}
NSError *error = nil;
NSManagedObject *refetchedObject = [managedObjectContext existingObjectWithID:managedObjectID error:&error];
NSCAssert(refetchedObject, @"Failed to find existing object with ID %@ in context %@: %@", managedObjectID, managedObjectContext, error);
return refetchedObject;
}
// Finds the key paths for all entity mappings in the graph whose parent objects are not other managed objects
static NSDictionary *RKDictionaryFromDictionaryWithManagedObjectsAtKeyPathsRefetchedInContext(NSDictionary *dictionaryOfManagedObjects, NSSet *keyPaths, NSManagedObjectContext *managedObjectContext)
{
if (! [dictionaryOfManagedObjects count]) return dictionaryOfManagedObjects;
NSMutableDictionary *newDictionary = [dictionaryOfManagedObjects mutableCopy];
[managedObjectContext performBlockAndWait:^{
for (NSString *keyPath in keyPaths) {
id value = RKMappedValueForKeyPathInDictionary(keyPath, dictionaryOfManagedObjects);
if (! value) {
continue;
} else if ([value isKindOfClass:[NSArray class]]) {
BOOL isMutable = [value isKindOfClass:[NSMutableArray class]];
NSMutableArray *newValue = [[NSMutableArray alloc] initWithCapacity:[value count]];
for (__strong id object in value) {
if ([object isKindOfClass:[NSManagedObject class]]) object = RKRefetchManagedObjectInContext(object, managedObjectContext);
if (object) [newValue addObject:object];
}
value = (isMutable) ? newValue : [newValue copy];
} else if ([value isKindOfClass:[NSSet class]]) {
BOOL isMutable = [value isKindOfClass:[NSMutableSet class]];
NSMutableSet *newValue = [[NSMutableSet alloc] initWithCapacity:[value count]];
for (__strong id object in value) {
if ([object isKindOfClass:[NSManagedObject class]]) object = RKRefetchManagedObjectInContext(object, managedObjectContext);
if (object) [newValue addObject:object];
}
value = (isMutable) ? newValue : [newValue copy];
} else if ([value isKindOfClass:[NSOrderedSet class]]) {
BOOL isMutable = [value isKindOfClass:[NSMutableOrderedSet class]];
NSMutableOrderedSet *newValue = [NSMutableOrderedSet orderedSet];
[(NSOrderedSet *)value enumerateObjectsUsingBlock:^(id object, NSUInteger index, BOOL *stop) {
if ([object isKindOfClass:[NSManagedObject class]]) object = RKRefetchManagedObjectInContext(object, managedObjectContext);
if (object) [newValue setObject:object atIndex:index];
}];
value = (isMutable) ? newValue : [newValue copy];
} else if ([value isKindOfClass:[NSManagedObject class]]) {
value = RKRefetchManagedObjectInContext(value, managedObjectContext);
}
if (value) RKSetMappedValueForKeyPathInDictionary(value, keyPath, newDictionary);
}
}];
return newDictionary;
}
static NSURL *RKRelativeURLFromURLAndResponseDescriptors(NSURL *URL, NSArray *responseDescriptors)
{
NSCParameterAssert(URL);
NSCParameterAssert(responseDescriptors);
NSArray *baseURLs = [responseDescriptors valueForKeyPath:@"@distinctUnionOfObjects.baseURL"];
if ([baseURLs count] == 1) {
NSURL *baseURL = [baseURLs objectAtIndex:0];
NSString *pathAndQueryString = RKPathAndQueryStringFromURLRelativeToURL(URL, baseURL);
URL = [NSURL URLWithString:pathAndQueryString relativeToURL:baseURL];
}
return URL;
}
@interface RKManagedObjectRequestOperation ()
// Core Data specific
@property (nonatomic, strong) NSManagedObjectContext *privateContext;
@property (nonatomic, copy) NSManagedObjectID *targetObjectID;
@property (nonatomic, strong) RKManagedObjectResponseMapperOperation *responseMapperOperation;
@property (nonatomic, strong, readwrite) NSError *error;
@property (nonatomic, strong, readwrite) RKMappingResult *mappingResult;
@property (nonatomic, copy) id (^willMapDeserializedResponseBlock)(id deserializedResponseBody);
@end
@implementation RKManagedObjectRequestOperation
@dynamic willMapDeserializedResponseBlock;
// Designated initializer
- (id)initWithHTTPRequestOperation:(RKHTTPRequestOperation *)requestOperation responseDescriptors:(NSArray *)responseDescriptors
{
self = [super initWithHTTPRequestOperation:requestOperation responseDescriptors:responseDescriptors];
if (self) {
self.savesToPersistentStore = YES;
self.deletesOrphanedObjects = YES;
}
return self;
}
- (void)setTargetObject:(id)targetObject
{
[super setTargetObject:targetObject];
if ([targetObject isKindOfClass:[NSManagedObject class]]) {
self.targetObjectID = [targetObject objectID];
}
}
- (void)setManagedObjectContext:(NSManagedObjectContext *)managedObjectContext
{
_managedObjectContext = managedObjectContext;
if (managedObjectContext) {
// Create a private context
NSManagedObjectContext *privateContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
[privateContext performBlockAndWait:^{
privateContext.parentContext = managedObjectContext;
privateContext.mergePolicy = NSMergeByPropertyStoreTrumpMergePolicy;
}];
self.privateContext = privateContext;
} else {
self.privateContext = nil;
}
}
#pragma mark - RKObjectRequestOperation Overrides
- (void)cancel
{
[super cancel];
[self.responseMapperOperation cancel];
}
- (RKMappingResult *)performMappingOnResponse:(NSError **)error
{
if (self.HTTPRequestOperation.wasNotModified) {
RKLogDebug(@"Managed object mapping requested for cached response: skipping mapping...");
NSURL *URL = RKRelativeURLFromURLAndResponseDescriptors(self.HTTPRequestOperation.response.URL, self.responseDescriptors);
NSArray *fetchRequests = RKArrayOfFetchRequestFromBlocksWithURL(self.fetchRequestBlocks, URL);
NSMutableArray *managedObjects = [NSMutableArray array];
[self.privateContext performBlockAndWait:^{
NSError *error = nil;
for (NSFetchRequest *fetchRequest in fetchRequests) {
NSArray *fetchedObjects = [self.privateContext executeFetchRequest:fetchRequest error:&error];
if (fetchedObjects) {
[managedObjects addObjectsFromArray:fetchedObjects];
} else {
RKLogError(@"Failed to execute fetch request %@: %@", fetchRequest, error);
}
}
}];
return [[RKMappingResult alloc] initWithDictionary:@{ [NSNull null]: managedObjects }];
}
self.responseMapperOperation = [[RKManagedObjectResponseMapperOperation alloc] initWithResponse:self.HTTPRequestOperation.response
data:self.HTTPRequestOperation.responseData
responseDescriptors:self.responseDescriptors];
self.responseMapperOperation.mapperDelegate = self;
self.responseMapperOperation.targetObjectID = self.targetObjectID;
self.responseMapperOperation.managedObjectContext = self.privateContext;
self.responseMapperOperation.managedObjectCache = self.managedObjectCache;
[self.responseMapperOperation setWillMapDeserializedResponseBlock:self.willMapDeserializedResponseBlock];
[self.responseMapperOperation setQueuePriority:[self queuePriority]];
[[RKObjectRequestOperation responseMappingQueue] addOperation:self.responseMapperOperation];
[self.responseMapperOperation waitUntilFinished];
if ([self isCancelled]) return nil;
if (self.responseMapperOperation.error) {
if (error) *error = self.responseMapperOperation.error;
return nil;
}
return self.responseMapperOperation.mappingResult;
}
- (BOOL)deleteTargetObjectIfAppropriate:(NSError **)error
{
__block BOOL _blockSuccess = YES;
if (self.targetObjectID
&& NSLocationInRange(self.HTTPRequestOperation.response.statusCode, RKStatusCodeRangeForClass(RKStatusCodeClassSuccessful))
&& [[[self.HTTPRequestOperation.request HTTPMethod] uppercaseString] isEqualToString:@"DELETE"]) {
// 2xx DELETE request, proceed with deletion from the MOC
__block NSError *_blockError = nil;
[self.privateContext performBlockAndWait:^{
NSManagedObject *backgroundThreadObject = [self.privateContext existingObjectWithID:self.targetObjectID error:&_blockError];
if (backgroundThreadObject) {
RKLogInfo(@"Deleting local object %@ due to `DELETE` request", backgroundThreadObject);
[self.privateContext deleteObject:backgroundThreadObject];
} else {
RKLogWarning(@"Unable to delete object sent with `DELETE` request: Failed to retrieve object with objectID %@", self.targetObjectID);
RKLogCoreDataError(_blockError);
_blockSuccess = NO;
*error = _blockError;
}
}];
}
return _blockSuccess;
}
- (NSSet *)localObjectsFromFetchRequestsMatchingRequestURL:(NSError **)error
{
NSMutableSet *localObjects = [NSMutableSet set];
__block NSError *_blockError;
__block NSArray *_blockObjects;
// Pass the fetch request blocks a relative `NSURL` object if possible
NSURL *URL = RKRelativeURLFromURLAndResponseDescriptors(self.HTTPRequestOperation.response.URL, self.responseDescriptors);
for (RKFetchRequestBlock fetchRequestBlock in [self.fetchRequestBlocks reverseObjectEnumerator]) {
NSFetchRequest *fetchRequest = fetchRequestBlock(URL);
if (fetchRequest) {
RKLogDebug(@"Found fetch request matching URL '%@': %@", URL, fetchRequest);
[self.privateContext performBlockAndWait:^{
_blockObjects = [self.privateContext executeFetchRequest:fetchRequest error:&_blockError];
}];
if (_blockObjects == nil) {
if (error) *error = _blockError;
return nil;
}
RKLogTrace(@"Fetched local objects matching URL '%@' with fetch request '%@': %@", URL, fetchRequest, _blockObjects);
[localObjects addObjectsFromArray:_blockObjects];
} else {
RKLogDebug(@"Fetch request block %@ returned nil fetch request for URL: '%@'", fetchRequestBlock, URL);
}
}
return localObjects;
}
- (BOOL)deleteLocalObjectsMissingFromMappingResult:(RKMappingResult *)result atKeyPaths:(NSSet *)keyPaths error:(NSError **)error
{
if (! self.deletesOrphanedObjects) {
RKLogDebug(@"Skipping deletion of orphaned objects: disabled as deletesOrphanedObjects=NO");
return YES;
}
if (! [[self.HTTPRequestOperation.request.HTTPMethod uppercaseString] isEqualToString:@"GET"]) {
RKLogDebug(@"Skipping deletion of orphaned objects: only performed for GET requests.");
return YES;
}
if (self.HTTPRequestOperation.wasNotModified) {
RKLogDebug(@"Skipping deletion of orphaned objects: 304 (Not Modified) status code encountered");
return YES;
}
// Build an aggregate collection of all the managed objects in the mapping result
NSMutableSet *managedObjectsInMappingResult = [NSMutableSet set];
NSDictionary *mappingResultDictionary = result.dictionary;
for (NSString *keyPath in keyPaths) {
id managedObjects = RKMappedValueForKeyPathInDictionary(keyPath, mappingResultDictionary);
if (! managedObjects) {
continue;
} else if ([managedObjects isKindOfClass:[NSManagedObject class]]) {
[managedObjectsInMappingResult addObject:managedObjects];
} else if ([managedObjects isKindOfClass:[NSSet class]]) {
[managedObjectsInMappingResult unionSet:managedObjects];
} else if ([managedObjects isKindOfClass:[NSArray class]]) {
[managedObjectsInMappingResult addObjectsFromArray:managedObjects];
} else if ([managedObjects isKindOfClass:[NSOrderedSet class]]) {
[managedObjectsInMappingResult addObjectsFromArray:[managedObjects array]];
} else {
[NSException raise:NSInternalInconsistencyException format:@"Unexpected object type '%@' encountered at keyPath '%@': Expected an `NSManagedObject`, `NSArray`, or `NSSet`.", [managedObjects class], keyPath];
}
}
NSSet *localObjects = [self localObjectsFromFetchRequestsMatchingRequestURL:error];
if (! localObjects) return NO;
RKLogDebug(@"Checking mappings result of %ld objects for %ld potentially orphaned local objects...", (long) [managedObjectsInMappingResult count], (long) [localObjects count]);
for (id object in localObjects) {
if (NO == [managedObjectsInMappingResult containsObject:object]) {
RKLogDebug(@"Deleting orphaned object %@: not found in result set and expected at this URL", object);
[self.privateContext performBlockAndWait:^{
[self.privateContext deleteObject:object];
}];
}
}
return YES;
}
- (BOOL)saveContext:(NSError **)error
{
__block BOOL success = YES;
__block NSError *localError = nil;
if ([self.privateContext hasChanges]) {
if (self.savesToPersistentStore) {
success = [self.privateContext saveToPersistentStore:&localError];
} else {
[self.privateContext performBlockAndWait:^{
success = [self.privateContext save:&localError];
}];
}
if (success) {
if ([self.targetObject isKindOfClass:[NSManagedObject class]]) {
[self.managedObjectContext performBlock:^{
RKLogDebug(@"Refreshing mapped target object %@ in context %@", self.targetObject, self.managedObjectContext);
[self.managedObjectContext refreshObject:self.targetObject mergeChanges:YES];
}];
}
} else {
if (error) *error = localError;
RKLogError(@"Failed saving managed object context %@ %@", (self.savesToPersistentStore ? @"to the persistent store" : @""), self.privateContext);
RKLogCoreDataError(localError);
}
}
return success;
}
- (BOOL)obtainPermanentObjectIDsForInsertedObjects:(NSError **)error
{
__block BOOL _blockSuccess = YES;
__block NSError *localError = nil;
NSArray *insertedObjects = [self.privateContext.insertedObjects allObjects];
if ([insertedObjects count] > 0) {
RKLogDebug(@"Obtaining permanent ID's for %ld managed objects", (unsigned long) [insertedObjects count]);
[self.privateContext performBlockAndWait:^{
_blockSuccess = [self.privateContext obtainPermanentIDsForObjects:insertedObjects error:&localError];
}];
if (!_blockSuccess && error) *error = localError;
}
return _blockSuccess;;
}
- (void)willFinish
{
BOOL success;
NSError *error = nil;
// Construct a set of key paths to all of the managed objects in the mapping result
RKNestedManagedObjectKeyPathMappingGraphVisitor *visitor = [[RKNestedManagedObjectKeyPathMappingGraphVisitor alloc] initWithResponseDescriptors:self.responseDescriptors];
NSSet *managedObjectMappingResultKeyPaths = visitor.keyPaths;
// Handle any cleanup
success = [self deleteTargetObjectIfAppropriate:&error];
if (! success) {
self.error = error;
return;
}
success = [self deleteLocalObjectsMissingFromMappingResult:self.mappingResult atKeyPaths:managedObjectMappingResultKeyPaths error:&error];
if (! success) {
self.error = error;
return;
}
// Persist our mapped objects
success = [self obtainPermanentObjectIDsForInsertedObjects:&error];
if (! success) {
self.error = error;
return;
}
success = [self saveContext:&error];
if (! success) self.error = error;
// Refetch all managed objects nested at key paths within the results dictionary before returning
if (self.mappingResult) {
NSSet *nonNestedKeyPaths = RKSetByRemovingSubkeypathsFromSet(managedObjectMappingResultKeyPaths);
NSDictionary *resultsDictionaryFromOriginalContext = RKDictionaryFromDictionaryWithManagedObjectsAtKeyPathsRefetchedInContext([self.mappingResult dictionary], nonNestedKeyPaths, self.managedObjectContext);
self.mappingResult = [[RKMappingResult alloc] initWithDictionary:resultsDictionaryFromOriginalContext];
}
}
@end