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我正在使用 Restkit 0.20 在核心数据中映射和存储对象。对于基本映射，它运行良好，但不适用于嵌套动态映射。这是我的示例响应：

[
    {
        "actor": {
            "id": 7,
            "first_name": "Murat",
            "last_name": "Akbal"
        },
        "target": {
            "content_type": "dress",
            "type": {
                "id": 1,
                "name": "leggings",
                "kind": "bottom"
            },
            "style": {
                "id": 1,
                "name": "sport"
            },
            "full_name": "Murat - sport leggings",
            "id": 19,
        }
    }, 
    {
        "actor": {
            "id": 7,
            "first_name": "Murat",
            "last_name": "Akbal"
        },
        "target": {
            "content_type": "wardrobe",
            "style": {
                "id": 1,
                "name": "sport"
            },
            "id": 38,
            "season": "spring",
            "name": "asdasd"
        }
    }
]

我使用以下实体映射来映射响应：

//create entity mapping
RKEntityMapping *objectMapping = [RKEntityMapping mappingForEntityForName:@"Action"
                                                     inManagedObjectStore:[RKObjectManager sharedManager].managedObjectStore];

//create dynamic mapping
RKDynamicMapping *dynamicMapping = [RKDynamicMapping new];    

//dressMapping and wardrobeMapping predefined mappings, they work well when mapping the wardobe and dress alone.
[dynamicMapping setObjectMappingForRepresentationBlock:^RKObjectMapping *(id representation) {
    if ([[representation valueForKey:@"content_type"] isEqualToString:@"wardrobe"]) {
       return wardrobeMapping;
    } else if ([[representation valueForKey:@"content_type"] isEqualToString:@"dress"]) {
       return dressMapping;
    }
    return nil;
}];


[objectMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"target" toKeyPath:@"target" withMapping:dynamicMapping]];

//maps actor
[objectMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"actor" toKeyPath:@"actor" withMapping:actorMapping]];

最后，我将 objectMapping 注册为响应描述符：

RKResponseDescriptor *responseDescriptor =
    [RKResponseDescriptor responseDescriptorWithMapping:objectMapping
                                            pathPattern:nil
                                                keyPath:nil
                                            statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
[[RKObjectManager sharedManager] addResponseDescriptor:responseDescriptor];

这不适用于我的示例响应，会出现以下错误：

*** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<Wardrobe 0x110e1a90> valueForUndefinedKey:]: the entity Wardrobe is not key value coding-compliant for the key "type".'

它询问衣柜中不存在的“类型”键，但存在于连衣裙中。不知何故，它试图用服装映射来映射衣柜。你对这个问题有什么想法吗？

仅供参考，coredata 中的目标类型是可转换的。

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1 回答 1

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我发现了问题。实际上它成功地映射了响应，但是当 deleteLocalObjectsMissingFromMappingResult 正在执行时，它会从该行抛出一个异常：

id managedObjects = event.keyPath ? [objectsAtRoot valueForKeyPath:event.keyPath] : objectsAtRoot;

它在映射结果中寻找所有对象的 keyPath，而不是每个单独的对象。所以在我的情况下，它找不到衣柜的“类型”键，因为它不存在。作为一个基本的解决方案，我用 try-catch 包围了代码块

于 2013-06-15T12:41:32.020 回答