Files
RestKit/Code/Network/RKManagedObjectRequestOperation.m
2012-10-28 20:22:53 -04:00

329 lines
13 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"
// Set Logging Component
#undef RKLogComponent
#define RKLogComponent RKlcl_cRestKitCoreData
NSFetchRequest *RKFetchRequestFromBlocksWithURL(NSArray *fetchRequestBlocks, NSURL *URL)
{
NSFetchRequest *fetchRequest = nil;
for (RKFetchRequestBlock block in [fetchRequestBlocks reverseObjectEnumerator]) {
fetchRequest = block(URL);
if (fetchRequest) break;
}
return fetchRequest;
}
static NSDictionary *RKDictionaryOfManagedObjectsInContextFromDictionaryOfManagedObjects(NSDictionary *dictionaryOfManagedObjects, NSManagedObjectContext *managedObjectContext)
{
NSMutableDictionary *newDictionary = [[NSMutableDictionary alloc] initWithCapacity:[dictionaryOfManagedObjects count]];
[managedObjectContext performBlockAndWait:^{
NSError *error = nil;
for (NSString *key in dictionaryOfManagedObjects) {
id value = dictionaryOfManagedObjects[key];
if ([value isKindOfClass:[NSArray class]]) {
NSMutableArray *newValue = [[NSMutableArray alloc] initWithCapacity:[value count]];
for (__strong id object in value) {
if ([object isKindOfClass:[NSManagedObject class]]) {
object = [managedObjectContext existingObjectWithID:[object objectID] error:&error];
NSCAssert(object, @"Failed to find existing object with ID %@ in context %@: %@", [object objectID], managedObjectContext, error);
}
[newValue addObject:object];
}
value = [newValue copy];
} else if ([value isKindOfClass:[NSManagedObject class]]) {
value = [managedObjectContext existingObjectWithID:[value objectID] error:&error];
NSCAssert(value, @"Failed to find existing object with ID %@ in context %@: %@", [value objectID], managedObjectContext, error);
}
[newDictionary setValue:value forKey:key];
}
}];
return newDictionary;
}
@interface RKManagedObjectRequestOperation () <RKMapperOperationDelegate>
// Core Data specific
@property (nonatomic, strong) NSManagedObjectContext *privateContext;
@property (nonatomic, copy) NSManagedObjectID *targetObjectID;
@property (nonatomic, strong) NSMutableDictionary *managedObjectsByKeyPath;
@property (nonatomic, strong) RKManagedObjectResponseMapperOperation *responseMapperOperation;
@property (nonatomic, strong, readwrite) NSError *error;
@property (nonatomic, strong, readwrite) RKMappingResult *mappingResult;
@end
@implementation RKManagedObjectRequestOperation
// Designated initializer
- (id)initWithHTTPRequestOperation:(RKHTTPRequestOperation *)requestOperation responseDescriptors:(NSArray *)responseDescriptors
{
self = [super initWithHTTPRequestOperation:requestOperation responseDescriptors:responseDescriptors];
if (self) {
self.savesToPersistentStore = 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;
// Create a private context
NSManagedObjectContext *privateContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
[privateContext performBlockAndWait:^{
privateContext.parentContext = self.managedObjectContext;
privateContext.mergePolicy = NSMergeByPropertyStoreTrumpMergePolicy;
}];
self.privateContext = privateContext;
}
#pragma mark - RKMapperOperationDelegate methods
- (void)mapper:(RKMapperOperation *)mapper didFinishMappingOperation:(RKMappingOperation *)mappingOperation forKeyPath:(NSString *)keyPath
{
if ([mappingOperation.destinationObject isKindOfClass:[NSManagedObject class]]) {
[self.managedObjectsByKeyPath setObject:mappingOperation.destinationObject forKey:keyPath];
}
}
#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...");
// TODO: This is unexpectedly returning an empty result set... need to be able to retrieve the appropriate objects...
return [[RKMappingResult alloc] initWithDictionary:@{}];
}
self.responseMapperOperation = [[RKManagedObjectResponseMapperOperation alloc] initWithResponse:self.HTTPRequestOperation.response
data:self.HTTPRequestOperation.responseData
responseDescriptors:self.responseDescriptors];
self.responseMapperOperation.targetObjectID = self.targetObjectID;
self.responseMapperOperation.managedObjectContext = self.privateContext;
self.responseMapperOperation.managedObjectCache = self.managedObjectCache;
[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 = [self.HTTPRequestOperation.request URL];
NSArray *baseURLs = [self.responseDescriptors valueForKeyPath:@"@distinctUnionOfObjects.baseURL"];
if ([baseURLs count] == 1) {
NSURL *baseURL = baseURLs[0];
NSString *pathAndQueryString = RKPathAndQueryStringFromURLRelativeToURL(URL, baseURL);
URL = [NSURL URLWithString:pathAndQueryString relativeToURL:baseURL];
}
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 error:(NSError **)error
{
if (! self.deletesOrphanedObjects) {
RKLogDebug(@"Skipping deletion of orphaned objects: deletesOrphanedObjects=NO");
return YES;
}
if (! [[self.HTTPRequestOperation.request.HTTPMethod uppercaseString] isEqualToString:@"GET"]) {
RKLogDebug(@"Skipping cleanup of objects via managed object cache: only used for GET requests.");
return YES;
}
NSArray *results = [result array];
NSSet *localObjects = [self localObjectsFromFetchRequestsMatchingRequestURL:error];
if (! localObjects) return NO;
for (id object in localObjects) {
if (NO == [results 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;
// Handle any cleanup
success = [self deleteTargetObjectIfAppropriate:&error];
if (! success) {
self.error = error;
return;
}
success = [self deleteLocalObjectsMissingFromMappingResult:self.mappingResult 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 the mapping results from the externally configured context
NSDictionary *resultsDictionaryFromOriginalContext = RKDictionaryOfManagedObjectsInContextFromDictionaryOfManagedObjects([self.mappingResult dictionary], self.managedObjectContext);
self.mappingResult = [[RKMappingResult alloc] initWithDictionary:resultsDictionaryFromOriginalContext];
}
@end