Question

所以我转而使用RestKit 0.2和CoreData，我在尝试使映射正确方面遇到了很多麻烦......我不明白为什么。我的服务器的JSON响应是这样的：

{
"meta": 
   {
   "limit": 20, 
   "next": null, 
   "offset": 0, 
   "previous": null, 
   "total_count": 2
   }, 
   "objects": 
   [{
       "creation_date": "2012-10-15T20:16:47", 
       "description": "", 
       "id": 1, 
       "last_modified": 
       "2012-10-15T20:16:47", 
       "order": 1, 
       "other_names": "", 
       "primary_name": "Mixing",
       "production_line": "/api/rest/productionlines/1/", 
       "resource_uri": "/api/rest/cells/1/"
   }, 
   {
       "creation_date": "2012-10-15T20:16:47", 
       "description": "",
       "id": 2, 
       "last_modified": "2012-10-15T20:16:47",
       "order": 2, "other_names": "", 
       "primary_name": "Packaging", 
       "production_line": "/api/rest/productionlines/1/",
       "resource_uri": "/api/rest/cells/2/"
   }]
}

然后在XCode中我有：

RKObjectManager *objectManager = [RKObjectManager sharedManager];

[AFNetworkActivityIndicatorManager sharedManager].enabled = YES;

NSManagedObjectModel *managedObjectModel = [NSManagedObjectModel mergedModelFromBundles:nil];
RKManagedObjectStore *managedObjectStore = [[RKManagedObjectStore alloc] initWithManagedObjectModel:managedObjectModel];
objectManager.managedObjectStore = managedObjectStore;


RKEntityMapping *cellMapping = [RKEntityMapping mappingForEntityForName:@"Cell" inManagedObjectStore:managedObjectStore];
cellMapping.primaryKeyAttribute = @"identifier";
[cellMapping addAttributeMappingsFromDictionary:@{
 @"id": @"identifier",
 @"primary_name": @"primaryName",
 }];



RKResponseDescriptor *responseCell = [RKResponseDescriptor responseDescriptorWithMapping:cellMapping
                                                                             pathPattern:@"/api/rest/cells/?format=json"
                                                                                 keyPath:@"objects"
                                                                             statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];


[objectManager addResponseDescriptorsFromArray:@[responseCell, responseUser, responseCompany]];


[managedObjectStore createPersistentStoreCoordinator];
NSString *storePath = [RKApplicationDataDirectory() stringByAppendingPathComponent:@"AppDB.sqlite"];
NSString *seedPath = [[NSBundle mainBundle] pathForResource:@"SeedDatabase" 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];

我的要求是：

    [[RKObjectManager sharedManager] getObjectsAtPath:@"/api/rest/cells/?format=json" parameters:nil success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
        RKLogInfo(@"Load complete: Table should refresh...");

        [[NSUserDefaults standardUserDefaults] setObject:[NSDate date] forKey:@"LastUpdatedAt"];
        [[NSUserDefaults standardUserDefaults] synchronize];
    } failure:^(RKObjectRequestOperation *operation, NSError *error) {
        RKLogError(@"Load failed with error: %@", error);
    }];

我总是收到以下错误：

**Error Domain=org.restkit.RestKit.ErrorDomain Code=1001 "Unable to find any mappings for the given content" UserInfo=0x1102d500 {DetailedErrors=(), NSLocalizedDescription=Unable to find any mappings for the given content, keyPath=null}**

非常感谢！

更新：我添加了cellMapping.forceCollectionMapping = YES; 但仍然没有运气:(！

更新＃2 ：按照Blake的建议，我尝试改变路径并且有效！我做了/ api / rest / cells /而不是/ api / rest / cells /？format = json我的服务器给了我所有的东西，映射成功了！

现在我遇到的唯一问题是以下错误：

2012-11-21 14：48：49.414 App [3125：617] W restkit.object_mapping：RKMapperOperation.m：176集合映射强制但可映射对象的类型为'__NSCFArray'而不是NSDictionary

Answer 1

听起来响应描述符无法匹配所请求的URL。两个想法：

尝试完全删除路径模式（传入nil）并仅使用基于密钥路径的匹配'cells'
尝试使用'/ api / rest / cells'

接下来我要尝试使用调试器逐步完成匹配。在RKObjectManager内，候选响应映射列表由RKFilteredArrayOfResponseDescriptorsMatchingPath函数构建。如果没有返回预期的响应映射，那么路径模式的请求路径将无法评估。

如果事情看起来不错，那么下一个可能发生不匹配的地方就是RKResponseMapperOperation方法中的buildResponseMappingsDictionary。此方法评估针对每个响应描述符的响应。如果响应无法与您的响应描述符匹配，那么您将在此处获得意外结果。

要检查的最终位置是在RKResponseMapperOperation内。这将从匹配的描述符中获取映射并应用它们。 RKMapperOperation main方法应包含您期望的反序列化响应以及mappingsDictionary属性上的相应映射。

Answer 2

即使设置似乎正确，映射也是错误的。映射调用的信息嵌套在给定对象中，因此您必须告诉映射查找对象内部的值。

RKEntityMapping *cellMapping = [RKEntityMapping mappingForEntityForName:@"Cell" inManagedObjectStore:managedObjectStore];
cellMapping.primaryKeyAttribute = @"identifier";

[cellMapping mapKeyOfNestedDictionaryToAttribute:@"objects"];
[cellMapping mapFromKeyPath:@".id" toAttribute:"identifier"];
[cellMapping mapFromKeyPath:@"primary_name" toAttribute:"primaryName"];

有关详细信息，请查看RKObjectMapping Reference。

“无法找到给定内容的任何映射，keyPath = null”RestKit 0.2

2 个答案: