Question

我尝试将JSON响应映射到NSManagedObject的实例，但我不了解如何正确设置关系/连接。

我的课程是：

@interface CloudObject : NSManagedObject
@property (nonatomic, retain) NSString *name;
@property (nonatomic, retain) CloudFolder *parent;
@end

@interface CloudFolder : CloudObject
@property (nonatomic, retain) NSSet *children;
@end

@interface CloudFile : CloudObject
@property (nonatomic, retain) NSString * mimeType;
@end

JSON是这样的：

{
    "name": "Folder1", 
    "is_dir": true,
    "contents": [
        { "name": "Folder2", "is_dir": true }
        { "name": "File1", "is_dir": false, "mime_type": "audio/mpeg" }
    ]
}

我使用RKDynamicMapping来映射响应（根对象）：

RKEntityMapping *fileMapping = [RKEntityMapping mappingForEntityForName:@"CloudFile" inManagedObjectStore:managedObjectStore];
[fileMapping addAttributeMappingsFromDictionary:@{@"name": @"name", @"mime_type": @"mimeType"}];
RKEntityMapping *folderMapping = [RKEntityMapping mappingForEntityForName:@"CloudFolder" inManagedObjectStore:managedObjectStore];
[folderMapping addAttributeMappingsFromDictionary:@{@"name": @"name"}];
RKDynamicMapping *objectMapping = [[RKDynamicMapping alloc] init];
[objectMapping addMatcher:[RKObjectMappingMatcher matcherWithKeyPath:@"is_dir" expectedValue:[NSNumber numberWithBool:NO] objectMapping:fileMapping]];
[objectMapping addMatcher:[RKObjectMappingMatcher matcherWithKeyPath:@"is_dir" expectedValue:[NSNumber numberWithBool:YES] objectMapping:folderMapping]];

但是我现在如何设置与@"contents"（也应该是RKDynamicMapping）和孩子/父母的关系/连接？（包含在＆＃39;内容中的文件夹＆＃39;没有＆＃39;内容＆＃39; -attribute）

Answer 1

查看有关动态映射的RestKit文档：Dynamic Object Mapping。

根据文档，在创建动态映射objectMapping后，您似乎应该添加此行：

[folderMapping addPropertyMapping:[RKRelationshipMapping relationshipMappingFromKeyPath:@"contents" toKeyPath:@"children" withMapping:objectMapping]];

您将"contents"属性指定为与动态映射映射。此外，您不必担心内部文件夹没有"contents"字段。如果"contents"不存在，RestKit应该优雅地忽略它，并且NSSet *children属性将自动设置为该对象的nil。

如何在RKEntityMapping包含在同一个JSON中时添加连接

1 个答案: