使用 RestKit 0.20 初始化核心数据

Posted 2023-03-04

【中文标题】使用 RestKit 0.20 初始化核心数据

【英文标题】：Core Data initialization using RestKit 0.20

【发布时间】：2013-04-16 13:47:42

【问题描述】：

我正在尝试将使用 Restkit 0.1 的现有应用更新到 0.20，但在设置 Core Data Stack 时遇到了一些问题，因为它遇到了异常。

我的 AppDelegate 上有以下代码：

     /*
     Complete Core Data stack initialization
     */
    NSError *error = nil;
    NSURL *modelURL = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"AppModel" ofType:@"momd"]];
    // NOTE: Due to an ios 5 bug, the managed object model returned is immutable.
    NSManagedObjectModel *managedObjectModel = [[[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL] mutableCopy];
    RKManagedObjectStore *managedObjectStore = [[RKManagedObjectStore alloc] initWithManagedObjectModel:managedObjectModel];
    [managedObjectStore createPersistentStoreCoordinator];
    NSString *storePath = [RKApplicationDataDirectory() stringByAppendingPathComponent:@"TSI.sqlite"];
    NSString *seedPath = [[NSBundle mainBundle] pathForResource:@"RKSeedDatabase" ofType:@"sqlite"];
    //NSPersistentStore __unused *persistentStore = [managedObjectStore addInMemoryPersistentStore:&error];
    NSPersistentStore *persistentStore = [managedObjectStore addSQLitePersistentStoreAtPath:storePath fromSeedDatabaseAtPath:seedPath withConfiguration:nil options:nil error:&error];
    NSAssert(persistentStore, @"Failed to add persistent store with error: %@", error);
    /*
     RESTKIT
    */
    // Create the managed object contexts
    [managedObjectStore createManagedObjectContexts];
     managedObjectStore.managedObjectCache = [[RKInMemoryManagedObjectCache alloc] initWithManagedObjectContext:managedObjectStore.persistentStoreManagedObjectContext];

然后我的映射被设置在 TableViewController 中：

    RKManagedObjectStore *managedObjectStore = [RKManagedObjectStore defaultStore];
    NSManagedObjectContext* context = [managedObjectStore mainQueueManagedObjectContext];

    NSString *rootKeyPath;
    rootKeyPath = @"body";
    NSString *endpoint = @"account/login.json";
    RKEntityMapping *entityMapping = [RKEntityMapping mappingForEntityForName:@"User" inManagedObjectStore:managedObjectStore];
    [entityMapping addAttributeMappingsFromDictionary:@
     @"api_token":@"token",
     @"email":   @"email",
     @"first_name":  @"name",
     @"last_name":   @"surname"
     ];
    RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:entityMapping pathPattern:endpoint keyPath:rootKeyPath statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:[TSI_SERVER stringByAppendingString:endpoint]]];
    RKManagedObjectRequestOperation *managedObjectRequestOperation = [[RKManagedObjectRequestOperation alloc] initWithRequest:request responseDescriptors:@[ responseDescriptor ]];
    //managedObjectRequestOperation.managedObjectContext = self.managedObjectContext;
    [[NSOperationQueue currentQueue] addOperation:managedObjectRequestOperation];

但是，每当我在视图加载后尝试检索数据时，我都会在控制台中收到以下错误（出于安全原因，我已经屏蔽了我的应用程序使用的名称和服务器）：

2013-04-16 14:41:50.576 <<MyApp>>[4525:907] I restkit:RKLog.m:34 RestKit logging initialized...
2013-04-16 14:41:51.009 <<MyApp>>[4525:907] [HEATMA.PS] Running Heatma.ps version 4.0.2. For help go to www.heatma.ps/support 
2013-04-16 14:42:54.464 <<MyApp>>[4525:3907] *** Assertion failure in
-[RKManagedObjectResponseMapperOperation performMappingWithObject:error:], /Users/manuel_matute/Code/RestKit/Code/Network/RKResponseMapperOperation.m:358 
2013-04-16 14:42:59.876 <<MyApp>>[4525:3907] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Unable to perform mapping: No `managedObjectContext` assigned. (Mapping response.URL = http://www.<<myserver>>.com/rest/account/login.json)'
 *** First throw call stack: (0x32a7b2a3 0x3a7a397f 0x32a7b15d 0x33350ab7 0xe37e1 0xe1b97 0x333085c1 0x33380be3 0x3abbb11f 0x3abbf961 0x3abbfac1 0x3abefa11 0x3abef8a4) libc++abi.dylib: terminate called throwing an exception

有人知道可能是什么问题吗？

谢谢！

【参考方案1】：

解决了！

看起来我需要将上下文显式分配给 managedObjectRequestOperation：

managedObjectRequestOperation.managedObjectContext = context;