Files
RestKit/Code/ObjectMapping/RKObjectLoader.m

262 lines
9.7 KiB
Objective-C

//
// RKObjectLoader.m
// RestKit
//
// Created by Blake Watters on 8/8/09.
// Copyright 2009 Two Toasters. All rights reserved.
//
#import <CoreData/CoreData.h>
#import "../CoreData/RKManagedObjectStore.h"
#import "RKObjectLoader.h"
#import "RKObjectManager.h"
#import "Errors.h"
#import "RKManagedObject.h"
#import "RKURL.h"
#import "RKNotifications.h"
@implementation RKObjectLoader
@synthesize mapper = _mapper, response = _response, objectClass = _objectClass, targetObject = _targetObject,
keyPath = _keyPath, managedObjectStore = _managedObjectStore;
+ (id)loaderWithResourcePath:(NSString*)resourcePath mapper:(RKObjectMapper*)mapper delegate:(NSObject<RKObjectLoaderDelegate>*)delegate {
return [[[self alloc] initWithResourcePath:resourcePath mapper:mapper delegate:delegate] autorelease];
}
- (id)initWithResourcePath:(NSString*)resourcePath mapper:(RKObjectMapper*)mapper delegate:(NSObject<RKObjectLoaderDelegate>*)delegate {
if (self = [self initWithURL:[[RKClient sharedClient] URLForResourcePath:resourcePath] delegate:delegate]) {
_mapper = [mapper retain];
self.managedObjectStore = nil;
_targetObjectID = nil;
[[RKClient sharedClient] setupRequest:self];
}
return self;
}
- (void)dealloc {
[_mapper release];
_mapper = nil;
[_response release];
_response = nil;
[_keyPath release];
_keyPath = nil;
[_targetObject release];
_targetObject = nil;
[_targetObjectID release];
_targetObjectID = nil;
self.managedObjectStore = nil;
[super dealloc];
}
- (void)setTargetObject:(NSObject<RKObjectMappable>*)targetObject {
[_targetObject release];
_targetObject = nil;
_targetObject = [targetObject retain];
[_targetObjectID release];
_targetObjectID = nil;
if ([targetObject isKindOfClass:[NSManagedObject class]]) {
_targetObjectID = [[(NSManagedObject*)targetObject objectID] retain];
}
}
#pragma mark Response Processing
- (void)responseProcessingSuccessful:(BOOL)successful withError:(NSError*)error {
_isLoading = NO;
NSDate* receivedAt = [NSDate date];
if (successful) {
_isLoaded = YES;
NSDictionary* userInfo = [NSDictionary dictionaryWithObjectsAndKeys:[self HTTPMethod], @"HTTPMethod",
[self URL], @"URL",
receivedAt, @"receivedAt",
nil];
[[NSNotificationCenter defaultCenter] postNotificationName:kRKResponseReceivedNotification
object:_response
userInfo:userInfo];
} else {
NSDictionary* userInfo = [NSDictionary dictionaryWithObjectsAndKeys:[self HTTPMethod], @"HTTPMethod",
[self URL], @"URL",
receivedAt, @"receivedAt",
error, @"error",
nil];
[[NSNotificationCenter defaultCenter] postNotificationName:kRKRequestFailedWithErrorNotification
object:self
userInfo:userInfo];
}
}
- (BOOL)encounteredErrorWhileProcessingRequest:(RKResponse*)response {
if ([response isFailure]) {
[(NSObject<RKObjectLoaderDelegate>*)_delegate objectLoader:self didFailWithError:response.failureError];
[self responseProcessingSuccessful:NO withError:response.failureError];
return YES;
} else if ([response isError]) {
NSError* error = nil;
if ([response isJSON]) {
error = [_mapper parseErrorFromString:[response bodyAsString]];
[(NSObject<RKObjectLoaderDelegate>*)_delegate objectLoader:self didFailWithError:error];
} else {
// TODO: We've likely run into a maintenance page here. Consider adding the ability
// to put the stack into offline mode in response...
if ([_delegate respondsToSelector:@selector(objectLoaderDidLoadUnexpectedResponse:)]) {
[(NSObject<RKObjectLoaderDelegate>*)_delegate objectLoaderDidLoadUnexpectedResponse:self];
}
}
[self responseProcessingSuccessful:NO withError:error];
return YES;
}
return NO;
}
- (void)informDelegateOfObjectLoadWithInfoDictionary:(NSDictionary*)dictionary {
NSArray* models = [dictionary objectForKey:@"models"];
[dictionary release];
// NOTE: The models dictionary may contain NSManagedObjectID's from persistent objects
// that were model mapped on a background thread. We look up the objects by ID and then
// notify the delegate that the operation has completed.
NSMutableArray* objects = [NSMutableArray arrayWithCapacity:[models count]];
for (id object in models) {
if ([object isKindOfClass:[NSManagedObjectID class]]) {
[objects addObject:[self.managedObjectStore objectWithID:(NSManagedObjectID*)object]];
} else {
[objects addObject:object];
}
}
[(NSObject<RKObjectLoaderDelegate>*)_delegate objectLoader:self didLoadObjects:[NSArray arrayWithArray:objects]];
[self responseProcessingSuccessful:YES withError:nil];
}
- (void)informDelegateOfObjectLoadErrorWithInfoDictionary:(NSDictionary*)dictionary {
NSError* error = [dictionary objectForKey:@"error"];
[dictionary release];
NSLog(@"[RestKit] RKObjectLoader: Error saving managed object context: error=%@ userInfo=%@", error, error.userInfo);
NSDictionary *userInfo = [NSDictionary dictionaryWithObjectsAndKeys:
[error localizedDescription], NSLocalizedDescriptionKey,
nil];
NSError *rkError = [NSError errorWithDomain:RKRestKitErrorDomain code:RKObjectLoaderRemoteSystemError userInfo:userInfo];
[(NSObject<RKObjectLoaderDelegate>*)_delegate objectLoader:self didFailWithError:rkError];
[self responseProcessingSuccessful:NO withError:rkError];
}
- (void)processLoadModelsInBackground:(RKResponse *)response {
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
RKManagedObjectStore* objectStore = self.managedObjectStore;
/**
* If this loader is bound to a particular object, then we map
* the results back into the instance. This is used for loading and updating
* individual object instances via getObject & friends.
*/
NSArray* results = nil;
if (self.targetObject) {
if (_targetObjectID) {
NSManagedObject* backgroundThreadModel = [self.managedObjectStore objectWithID:_targetObjectID];
[_mapper mapObject:backgroundThreadModel fromString:[response bodyAsString]];
results = [NSArray arrayWithObject:backgroundThreadModel];
} else {
[_mapper mapObject:self.targetObject fromString:[response bodyAsString]];
results = [NSArray arrayWithObject:self.targetObject];
}
} else {
id result = [_mapper mapFromString:[response bodyAsString] toClass:self.objectClass keyPath:_keyPath];
if ([result isKindOfClass:[NSArray class]]) {
results = (NSArray*)result;
} else {
// Using arrayWithObjects: instead of arrayWithObject:
// so that in the event result is nil, then we get empty array instead of exception for trying to insert nil.
results = [NSArray arrayWithObjects:result, nil];
}
if (objectStore && [objectStore managedObjectCache]) {
if ([self.URL isKindOfClass:[RKURL class]]) {
RKURL* rkURL = (RKURL*)self.URL;
NSArray* fetchRequests = [[objectStore managedObjectCache] fetchRequestsForResourcePath:rkURL.resourcePath];
NSArray* cachedObjects = [RKManagedObject objectsWithFetchRequests:fetchRequests];
for (id object in cachedObjects) {
if ([object isKindOfClass:[RKManagedObject class]]) {
if (NO == [results containsObject:object]) {
[[objectStore managedObjectContext] deleteObject:object];
}
}
}
}
}
}
// Before looking up NSManagedObjectIDs, need to save to ensure we do not have
// temporary IDs for new objects prior to handing the objectIDs across threads
NSError* error = [objectStore save];
if (nil != error) {
NSDictionary* infoDictionary = [[NSDictionary dictionaryWithObjectsAndKeys:response, @"response", error, @"error", nil] retain];
[self performSelectorOnMainThread:@selector(informDelegateOfObjectLoadErrorWithInfoDictionary:) withObject:infoDictionary waitUntilDone:YES];
} else {
// NOTE: Passing Core Data objects across threads is not safe.
// Iterate over each model and coerce Core Data objects into ID's to pass across the threads.
// The object ID's will be deserialized back into objects on the main thread before the delegate is called back
NSMutableArray* models = [NSMutableArray arrayWithCapacity:[results count]];
for (id object in results) {
if ([object isKindOfClass:[NSManagedObject class]]) {
[models addObject:[(NSManagedObject*)object objectID]];
} else {
[models addObject:object];
}
}
NSDictionary* infoDictionary = [[NSDictionary dictionaryWithObjectsAndKeys:response, @"response", models, @"models", nil] retain];
[self performSelectorOnMainThread:@selector(informDelegateOfObjectLoadWithInfoDictionary:) withObject:infoDictionary waitUntilDone:YES];
}
[pool drain];
}
- (void)didFailLoadWithError:(NSError*)error {
if ([_delegate respondsToSelector:@selector(request:didFailLoadWithError:)]) {
[_delegate request:self didFailLoadWithError:error];
}
[(NSObject<RKObjectLoaderDelegate>*)_delegate objectLoader:self didFailWithError:error];
[self responseProcessingSuccessful:NO withError:error];
}
- (void)didFinishLoad:(RKResponse*)response {
_response = [response retain];
if ([_delegate respondsToSelector:@selector(request:didLoadResponse:)]) {
[_delegate request:self didLoadResponse:response];
}
if (NO == [self encounteredErrorWhileProcessingRequest:response]) {
// TODO: When other mapping formats are supported, unwind this assumption...
if ([response isSuccessful] && [response isJSON]) {
[self performSelectorInBackground:@selector(processLoadModelsInBackground:) withObject:response];
} else {
NSLog(@"Encountered unexpected response code: %d (MIME Type: %@)", response.statusCode, response.MIMEType);
if ([_delegate respondsToSelector:@selector(objectLoaderDidLoadUnexpectedResponse:)]) {
[(NSObject<RKObjectLoaderDelegate>*)_delegate objectLoaderDidLoadUnexpectedResponse:self];
}
[self responseProcessingSuccessful:NO withError:nil];
}
}
}
@end