Restkit嵌套对象映射问题

Posted 2023-03-05

【中文标题】Restkit嵌套对象映射问题

【英文标题】：Restkit nested Object mapping issue

【发布时间】：2014-07-15 12:14:05

【问题描述】：

我正在尝试使用以下 json 结构填充两个核心数据实体。

  "fldrs": [
    
      "FldName": "Messages",
      "FldID": "Messages",
      "PrntFldID": null,
      "UnRdCunt": "0",
      "Cunt": "0",
      "IsDflt": "True",
      "FldIconID": null,
      "SubFldrs": [
        
          "FldName": "Compose",
          "FldID": "INDV9",
          "PrntFldID": "Messages",
          "UnRdCunt": "0",
          "Cunt": "0",
          "IsDflt": "False",
          "FldIconID": null,
          "SubFldrs": null,
          "tasksLists": null
        ,
        
          "FldName": "Inbox",
          "FldID": "INDV10",
          "PrntFldID": "Messages",
          "UnRdCunt": "2",
          "Cunt": "12",
          "IsDflt": "True",
          "FldIconID": null,
          "SubFldrs": null,
          "tasksLists": null
        
      ],
      "tasksLists": null
    ,
    
      "FldName": "My Tasks",
      "FldID": "My Tasks",
      "PrntFldID": null,
      "UnRdCunt": "0",
      "Cunt": "0",
      "IsDflt": "False",
      "FldIconID": null,
      "SubFldrs": [
        
          "FldName": "Pending",
          "FldID": "INDV1",
          "PrntFldID": "My Tasks",
          "UnRdCunt": "9",
          "Cunt": "9",
          "IsDflt": "False",
          "FldIconID": null,
          "SubFldrs": null,
          "tasksLists": null
        
      ],
      "tasksLists": null
    
  ]

这里的“SubFldrs”是“flds”的子实体。

这是我正在使用的数据模型

以下是使用的模型类

@class ParentFolder;

@interface SubFolder : NSManagedObject

@property (nonatomic, retain) NSString * fldId;
@property (nonatomic, retain) NSString * fldName;
@property (nonatomic, retain) NSString * isDefault;
@property (nonatomic, retain) NSString * msgCount;
@property (nonatomic, retain) NSString * prntFolderId;
@property (nonatomic, retain) NSString * unreadCount;
@property (nonatomic, retain) ParentFolder *subFolder_folder;

#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>

@class SubFolder;

@interface ParentFolder : NSManagedObject

@property (nonatomic, retain) NSString * fldId;
@property (nonatomic, retain) NSString * fldName;
@property (nonatomic, retain) NSSet *folder_SubFolder;
@end

@interface ParentFolder (CoreDataGeneratedAccessors)

- (void)addFolder_SubFolderObject:(SubFolder *)value;
- (void)removeFolder_SubFolderObject:(SubFolder *)value;
- (void)addFolder_SubFolder:(NSSet *)values;
- (void)removeFolder_SubFolder:(NSSet *)values;

@end

Restkit Mapping 是通过以下代码完成的

RKObjectMapping* subFolderMapping = [RKObjectMapping mappingForClass:[SubFolder class] ];
    [subFolderMapping addAttributeMappingsFromDictionary:@
                                                           @"FldName":   @"fldName",
                                                           @"FldID":   @"fldId",
                                                           @"IsDflt":   @"isDefault",
                                                           @"UnRdCunt":   @"unreadCount",
                                                           @"Cunt":   @"msgCount",
                                                           @"PrntFldID":   @"prntFolderId"
                                                           ];

    RKObjectMapping* folderMapping = [RKObjectMapping mappingForClass:[ParentFolder class] ];
    [folderMapping addAttributeMappingsFromDictionary:@
                                                        @"FldID":  @"fldId",
                                                        @"FldName": @"fldName"
                                                        ];

    [folderMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"subFolder"
                                                                                   toKeyPath:@"SubFldrs"
                                                                                 withMapping:subFolderMapping]];

    RKResponseDescriptor *responseDescriptor = [RKResponseDescriptor responseDescriptorWithMapping:folderMapping
                                                                                            method:RKRequestMethodGET
                                                                                       pathPattern:nil
                                                                                           keyPath:@"fldrs"
                                                                                       statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
    return responseDescriptor;

父实体 (ParentFolder) 正在按要求填充，但子实体 (SubFolder) 始终为空。 谁能帮帮我？

【参考方案1】：

在您创建关系映射时，您的键似乎顺序错误：

[folderMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"SubFldrs"
                                                                              toKeyPath:@"subFolder"
                                                                            withMapping:subFolderMapping]];

【讨论】：

子表填充了空值并且只有一条记录可用。请帮帮我。

刚刚注意到您展示了一个核心数据模型并讨论了表，但您使用了NSObject 子类和对象映射。您是否使用 Core Data？

抱歉，实际上这些只是 NSManagedObject 的子类。我将编辑我的问题。现在我可以根据您的建议正确保存数据。非常感谢:-)

如果您也可以更正问题中的映射（针对实体而不是对象）以帮助将来查看此问题的人，那就太好了。