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标题: objective-c - RestKit - 水合外键数组 [打印本页]

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作者: 菜鸟教程小白    时间: 2022-12-12 23:54
标题: objective-c - RestKit - 水合外键数组

我有以下 JSON:

{
    "users": [
        {"id": "1", "name": "John Doe"},
        {"id": "2", "name": "Bill Nye"}
    ],
    "groups": [
        {"id": "1", "name": "Group1", "users": ["1", "2"]},
        {"id": "2", "name": "Group2", "users": ["1"]}
    ]
}

...以及带有用户和组对象的核心数据模型。组对象与用户具有一对多关系 (NSSet)。

我发现以下线程似乎表明这是可能的，但没有解释如何执行这种映射:

https://github.com/RestKit/RestKit/issues/284

如何执行此映射以正确连接每个组的“用户”关系？

注意:我已设置映射，可将 JSON 用户和组正确映射到其各自的核心数据对象。但是，每个组的“用户”NSSet 是空的。

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Best Answer-推荐答案

所以，我使用 RestKit 0.20(pre2) 解决了这个问题。

JSON 需要更改为以下内容(注意组的 users 数组中的属性名称):

{
    "users": [
        {"id": "1", "name": "John Doe"},
        {"id": "2", "name": "Bill Nye"}
    ],
    "groups": [
        {"id": "1", "name": "Group1", "users": [{"id" : "1"}, {"id" : "2"}]},
        {"id": "2", "name": "Group2", "users": [{"id" : "1"}]}
    ]
}

然后，以下映射:

RKEntityMapping *userMapping = [RKEntityMapping mappingForEntityForName"User" inManagedObjectStore:managedObjectStore];
userMapping.identificationAttributes = @[@"id"];
[userMapping addAttributeMappingsFromArray[@"id", @"name"]];
RKEntityMapping *groupMapping = [RKEntityMapping mappingForEntityForName"Group" inManagedObjectStore:managedObjectStore];
groupMapping.identificationAttributes = @[@"id"];
[groupMapping addAttributeMappingsFromArray[@"id", @"name"]];
[groupMapping addRelationshipMappingWithSourceKeyPath"users" mapping:userMapping];

最后是下面的 responseDescriptors:

RKResponseDescriptor *userResponseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:classMapping pathPattern"/api/allthejson" keyPath"users" statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
RKResponseDescriptor *groupResponseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:classMapping pathPattern"/api/allthejson" keyPath"groups" statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
[objectManager addResponseDescriptorsArray[userResponseDescriptor, groupResponseDescriptor]];

然后使用 RKObjectManager 的 getObjectsAtPath:parameters:success:failure 方法获取您的对象，您就完成了!

关于objective-c - RestKit - 水合外键数组，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/13726203/

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