无法映射嵌套的 RestKit 对象

Posted 2023-03-16

【中文标题】无法映射嵌套的 RestKit 对象

【英文标题】：Can't map nested RestKit object

【发布时间】：2014-02-03 07:45:44

【问题描述】：

我有一个问题，无法映射 json 的嵌套对象。问题出在“容量”键上。

这是错误：

restkit.object_mapping:RKMappingOperation.m:830 Did not find mappable relationship value keyPath 'capacities'

我知道问题出在映射本身，但就是想不通：

RKObjectMapping *capacityMapping = [RKObjectMapping mappingForClass:[Capacity class]];
[capacityMapping addAttributeMappingsFromDictionary:@ @"capacityText" : @"capacityText",
                                                       @"priceDescriptionText" : @"priceDescriptionText",
                                                       @"priceText" : @"priceText" ];

RKObjectMapping *colorsMapping = [RKObjectMapping mappingForClass:[Colors class]];
[colorsMapping addAttributeMappingsFromDictionary:@ @"ID" : @"idNum",
                                                     @"Name" : @"name",
                                                     @"colorHex" : @"colorHex",
                                                     @"imageUrl" : @"imageURL" ];

RKObjectMapping *deviceDataMapping = [RKObjectMapping mappingForClass:[DeviceData class]];
[deviceDataMapping addAttributeMappingsFromDictionary:@ @"device.ID" : @"idNum",
                                                         @"device.Name" : @"name",
                                                         @"device.additionalFeatures" : @"additionalFeatures",
                                                         @"device.deviceName" : @"deviceName",
                                                         @"device.mainFeatures" : @"mainFeatures",
                                                         @"device.supportPagesLinks" : @"supportPagesLinks",
                                                         @"device.whatsInTheKit" : @"whatsInTheKit" ];

[deviceDataMapping addRelationshipMappingWithSourceKeyPath:@"capacities" mapping:capacityMapping];

[capacityMapping addRelationshipMappingWithSourceKeyPath:@"colors" mapping:colorsMapping];

[deviceDataMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"responseError"
                                                                                  toKeyPath:@"responseError"
                                                                                withMapping:errorMapping]];

[[RKObjectManager sharedManager] addResponseDescriptor:[RKResponseDescriptor responseDescriptorWithMapping:deviceDataMapping
                                                                                                    method:RKRequestMethodGET
                                                                                               pathPattern:@"devices/:boneID"
                                                                                                   keyPath:nil
                                                                                               statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)]];

这是DeviceData 类：

@interface DeviceData : NSObject
@property (nonatomic) ResponseError *responseError;
@property (copy, nonatomic) NSString *idNum;
@property (copy, nonatomic) NSString *name;
@property (copy, nonatomic) NSString *additionalFeatures;
@property (copy, nonatomic) NSString *deviceName;
@property (copy, nonatomic) NSString *mainFeatures;
@property (copy, nonatomic) NSString *supportPagesLinks;
@property (copy, nonatomic) NSString *whatsInTheKit;
@property (nonatomic) NSArray *capacities;
@property (assign, nonatomic) NSInteger boneID;
@end

这是Capacity 类：

@interface Capacity : NSObject
@property (copy, nonatomic) NSString *capacityText;
@property (nonatomic) NSArray *colors;
@property (copy, nonatomic) NSString *priceDescriptionText;
@property (copy, nonatomic) NSString *priceText;
@end

这是Colors 类：

@interface Colors : NSObject
@property (copy, nonatomic) NSString *idNum;
@property (copy, nonatomic) NSString *name;
@property (copy, nonatomic) NSString *colorHex;
@property (copy, nonatomic) NSString *imageURL;
@end

这是json：

  "responseError": null,
  "device": 
    "ID": null,
    "Name": null,
    "additionalFeatures": "additional features text",
    "capacities": [
      
        "capacityText": "16GB",
        "colors": [
          
            "ID": null,
            "Name": null,
            "colorHex": "#a68f76",
            "imageUrl": "iphone_5s_black.png"
          ,
          
            "ID": null,
            "Name": null,
            "colorHex": "#a9a9a9",
            "imageUrl": "iphone_5s_black.png"
          ,
          
            "ID": null,
            "Name": null,
            "colorHex": "#616065",
            "imageUrl": "iphone_5s_black.png"
          
        ],
        "priceDescriptionText": “iPhone 5S",
        "priceText": "750$"
      ,
        "capacityText": “32GB",
        "colors": [
          
            "ID": null,
            "Name": null,
            "colorHex": "#a68f76",
            "imageUrl": "iphone_5s_black.png"
          ,
          
            "ID": null,
            "Name": null,
            "colorHex": "#a9a9a9",
            "imageUrl": “iphone_5s_black.png"
          ,
          
            "ID": null,
            "Name": null,
            "colorHex": "#616065",
            "imageUrl": “iphone_5s_black.png"
          
        ],
        "priceDescriptionText": “iPhone 5S",
        "priceText": "750$"
      
    ],
    "deviceName": "iPhone 5s",
    "mainFeatures": “some main features text",
    "supportPagesLinks": [
      
        "linkText": “restore",
        "linkUrl": “restore.pdf"
      ],
    "whatsInTheKit": "what inside the kit text"
  

【参考方案1】：

因为您的响应描述符有一个 nil 键路径，并且您在 deviceMapping 的所有源键路径中使用 device.xxx，所以您需要有一个明确的关系映射，以便您可以指定源和目标键路径：

RKRelationshipMapping *capacitiesMapping = [RKRelationshipMapping relationshipMappingFromKeyPath:@"device.capacities" toKeyPath:@"capacities" withMapping:capacityMapping];
[deviceDataMapping addPropertyMapping:capacitiesMapping];

【讨论】：

是的，我已经这样做了，但是没有成功，结果是：*** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<RKDeviceData 0x165647f0> valueForUndefinedKey:]: this class is not key value coding-compliant for the key device.'，这是为什么呢？

是的，我猜你犯了一个错误，并且已经尝试过了，而且效果很好。无论如何感谢您的帮助，这很有帮助。

...我已经知道该怎么做了！ - 但错过了一个事实，即在 API 中，一条数据已被下移……无论哪种方式，您的回答都提醒我再次检查，所以谢谢！