Restkit 映射嵌套数组答案

【问题标题】：Restkit Mapping Nested ArrayRestkit 映射嵌套数组
【发布时间】：2012-04-24 09:17:54
【问题描述】：

我有一个关于映射嵌套数组的问题。在https://github.com/RestKit/RestKit/blob/master/Docs/Object%20Mapping.md 上有一个映射嵌套对象的示例。

但是如果嵌套对象是一个对象数组，我该怎么办，例如 JSON 看起来像这样：

{ "articles": [
    { "title": "RestKit Object Mapping Intro",
      "body": "This article details how to use RestKit object mapping...",
      "author": [{
          "name": "Blake Watters",
          "email": "blake@restkit.org"
      },
      {
          "name": "abc",
          "email": "emailaddress"
      }]
      "publication_date": "7/4/2011"
    }]
}

为了获得一组作者，我的课程应该是什么样子？这就是示例中的代码：

@interface Author : NSObject
    @property (nonatomic, retain) NSString* name;
    @property (nonatomic, retain) NSString* email;
@end



@interface Article : NSObject
    @property (nonatomic, retain) NSString* title;
    @property (nonatomic, retain) NSString* body;
    @property (nonatomic, retain) Author* author; // should be an array of Author-Objects
    @property (nonatomic, retain) NSDate*   publicationDate;
@end

我如何告诉 Restkit，有一个作者数组，如果我将文章中的作者属性的类更改为 NSArray，Restkit 怎么知道，在这个 NSArray 中应该是 Author-Objects...？

我正在使用 RKObjectMapping 将对象从 JSON 映射到 Objective-c，反之亦然。

【问题讨论】：

标签： objective-c ios5 restkit

【解决方案1】：

您需要确保相应地设置了 var 类型：

@interface Article : NSObject
    @property (nonatomic, retain) NSString* title;
    @property (nonatomic, retain) NSString* body;
    @property (nonatomic, retain) NSSet* authors;
    @property (nonatomic, retain) NSDate*   publicationDate;
@end

它可以将其声明为 NSArray，但我个人将 RestKit 与 CoreData 模型一起使用，并且这些场景中的关系是 NSSet 的。

另外，你需要设置映射：

[articleMapping mapKeyPath:@"author" toRelationship:@"authors" withMapping:authorMapping];

【讨论】：

【解决方案2】：

拆分出来会有帮助。

@interface Author : NSObject
    @property (nonatomic, retain) NSString* name;
    @property (nonatomic, retain) NSString* email;
@end



@interface Article : NSObject
    @property (nonatomic, retain) NSString* title;
    @property (nonatomic, retain) NSString* body;
    @property (nonatomic, retain) NSArray* author; 
    @property (nonatomic, retain) NSDate*   publicationDate;
@end


//create the article mapping
RKObjectMapping *articleMapping = [RKObjectMapping mappingForClass:[Article class]];
//add rest of mappings here
[articleMapping addAttributeMappingsFromDictionary:@{
                                                  @"title":@"title"
} 

//create the author mapping
RKObjectMapping *authorMapping = [RKObjectMapping mappingForClass:[Author class]];
//add rest of mappings here
[authorMapping addAttributeMappingsFromDictionary:@{
                                                  @"name":@"name"
} 

//link mapping with a relationship
RKRelationshipMapping *rel = [RKRelationshipMapping relationshipMappingFromKeyPath:@"authors" toKeyPath:@"author" withMapping:authorMapping];

//add relationship mapping to article
[articleMapping addPropertyMapping:rel];

【讨论】：

【解决方案3】：

整个响应字符串将其作为 nsmutable 字典，然后将作者值分配给可命名数组..

【讨论】：

【解决方案4】：

您需要做的是使用 NSSet 属性来保存嵌套数组。这是一份完整的指南，绝对可以帮助您做到这一点https://medium.com/ios-os-x-development/restkit-tutorial-how-to-fetch-data-from-an-api-into-core-data-9326af750e10。

【讨论】：