iOS RestKit无法将本地实体保存到数据库

Question

我使用RestKit 0.20来解析JSON数据并保存到数据库.这是一个映射的实体SchoolClass,由RestKit处理并保存好.我有另一个名为MyClass的实体,它存储我选择的类.这个只在设备上本地.

这是我创建的代码并保存MyClass实体

 NSManagedObjectContext *managedObjCtx = [RKManagedObjectStore defaultStore].mainQueueManagedObjectContext;
 MyClass* course = [managedObjCtx insertNewObjectForEntityForName:@"MyClass"];

 .. set the data for course here

 NSError *executeError = nil;
 if(![managedObjCtx save:&executeError]) {
      NSLog(@"Failed to save to data store");
 }

以下是初始化托管数据存储的代码

  // Initialize managed object store
    NSManagedObjectModel *managedObjectModel = [NSManagedObjectModel mergedModelFromBundles:nil];
    RKManagedObjectStore *managedObjectStore = [[RKManagedObjectStore alloc] initWithManagedObjectModel:managedObjectModel];
    objectManager.managedObjectStore = managedObjectStore;

   /**
     Complete Core Data stack initialization
     */
    [managedObjectStore createPersistentStoreCoordinator];
    NSString *storePath = [RKApplicationDataDirectory() stringByAppendingPathComponent:@"RKMainDb.sqlite"];
    NSString *seedPath = [[NSBundle mainBundle] pathForResource:@"RKSeedDatabase" ofType:@"sqlite"];
    NSError *error;
    NSPersistentStore *persistentStore = [managedObjectStore addSQLitePersistentStoreAtPath:storePath fromSeedDatabaseAtPath:seedPath withConfiguration:nil options:nil error:&error];
    NSAssert(persistentStore, @"Failed to add persistent store with error: %@", error);

    // Create the managed object contexts
    [managedObjectStore createManagedObjectContexts];

    // Configure a managed object cache to ensure we do not create duplicate objects
    managedObjectStore.managedObjectCache = [[RKInMemoryManagedObjectCache alloc] initWithManagedObjectContext:managedObjectStore.persistentStoreManagedObjectContext];

看来保存成功了,在MyClasseTableViewController中我可以读取保存的MyClass条目.然而,在我关闭应用程序并重新启动后.MyClassTableViewController为空,因为获取的结果为空.我使用SQLiteBrowser打开了sqlite文件,MyClass表为空.看起来MyClass实体仅保存在缓存中,但不保存在持久性存储中.我是否需要调用RestKit提供的一些API来保存它？我试图阅读文档,但找不到它.请帮忙.

Answer 1

感谢Tom的领导,我发现RestKit有一个NSManagedObjectContext(RKAdditions),它有一个方法:

- (BOOL)saveToPersistentStore:(NSError **)error

是的,它有逻辑来处理嵌套的托管对象上下文.这是新的代码,只有一行更改,但花了很多时间来找到正确的调用:(

#import "NSManagedObjectContext+RKAdditions.h"
     NSManagedObjectContext *managedObjCtx = [RKManagedObjectStore defaultStore].mainQueueManagedObjectContext;
     MyClass* course = [managedObjCtx insertNewObjectForEntityForName:@"MyClass"];

     .. set the data for course here

     NSError *executeError = nil;
     if(![managedObjCtx saveToPersistentStore:&executeError]) {
          NSLog(@"Failed to save to data store");
     }