RestKit - 多类型子数组映射答案

【问题标题】：RestKit - Multi-type subarray mappingRestKit - 多类型子数组映射
【发布时间】：2017-03-11 11:21:11
【问题描述】：

我正在使用 RestKit 在我的 iOS 项目中映射 JSON 对象。到目前为止一切正常，但我在映射自定义类型的子数组时遇到了问题。

JSON 如下所示：

{ "Result" : "OK", "Total": "1","content": [ 
    {"article": 
        {
        "title": "sample_title",
        "author": "sample_author",
        "article_details": [
            {"text": 
                {
                "body": "sample_body",
                }
            },
            {"image": 
                {
                "image": "sample_image"
                }
            },
            {"quote": 
                {
                "quote": "sample_quote",
                }
            }
            {"text": 
                {
                "body": "sample_body",
                }
            },
        ]}
    }]
}

请注意，article_detail 对象类型可以以任意数量或顺序出现。此外，重要的是要注意我需要存储这些对象出现的顺序，以及它的每个类型。

为此，为了简化数据操作，我使用 CoreData 自动生成了两个 NSManagedObjects。如下：

extension Article {
    public var title: String?
    public var author: String?
    public var details: NSOrderedSet?
}

extension ArticleDetail {
    public var body: String?
    public var image: String?
    public var quote: String?
}

我的映射如下：

//Detail mapping
let detailsMapping = RKEntityMapping(forEntityForName: "ArticleDetail", in: objectManager.managedObjectStore)
detailsMapping?.addAttributeMappings(from: [
    "image"     : "image",
    "body"      : "body",
    "quote"     : "quote",
    ]
)

//Article mapping
let articleMapping = RKEntityMapping(forEntityForName: "Article", in: objectManager.managedObjectStore)
articleMapping?.addAttributeMappings(from: [
    "title"          : "title",
    "author"         : "author",
    ]
)

//Relation mapping
articleMapping!.addPropertyMapping(RKRelationshipMapping(fromKeyPath: "article_details.text", toKeyPath: "details", with: detailsMapping))

//Response descriptior
let articleResponseDescriptor = RKResponseDescriptor(
    mapping: articleMapping,
    method: RKRequestMethod.GET,
    pathPattern: nil,
    keyPath: "content.article",
    statusCodes: IndexSet(integer: 200)
)
objectManager.addResponseDescriptor(articleResponseDescriptor)

这适用于文章信息。然而，正如预期的那样，由于

fromKeyPath: "article_details.text"

它只映射“文本”对象。

识别类型很容易，检查文章详细对象中哪些参数为nil。

类似的问题可以在 RestKit - Map keypath of an array to the object inside of that array

我怎样才能在 Swift 中使用 RestKit 来完成这项工作？

非常感谢。

-N

【问题讨论】：

标签： ios json swift core-data restkit

【解决方案1】：

我昨天设法解决了这个问题。我使用一个类作为每个自定义对象的“包装器”。

因此，文章仅包含一组有序的 Wrappers，如果这些对象保存顺序，则该 wrapper 包含文章详细信息。像这样：

extension Article {
    public var title: String?
    public var author: String?
    public var details: NSOrderedSet?
}

extension ArticleWrapper {
    public var app_text: ArticleTextDetail?
    public var app_image: ArticleImageDetail?
    public var app_quote: ArticleQuoteDetail?
}

extension ArticleTextDetail {
    ...
}    

extension ArticleImageDetail {
    ...
}  

extension ArticleQuoteDetail {
    ...
}

映射如下所示：

let wrapperMapping = RKEntityMapping(forEntityForName: "ArticleWrapper", in: objectManager.managedObjectStore)


let textMapping = RKEntityMapping(forEntityForName: "ArticleTextDetail", in: objectManager.managedObjectStore)
...

let imageMapping = RKEntityMapping(forEntityForName: "ArticleImageDetail", in: objectManager.managedObjectStore)
...

let quoteMapping = RKEntityMapping(forEntityForName: "ArticleQuoteDetail", in: objectManager.managedObjectStore)
...

let articleMapping = RKEntityMapping(forEntityForName: "Article", in: objectManager.managedObjectStore)
articleMapping?.addAttributeMappings(from: [
"title"          : "title",
"author"         : "author",
    ]
)

wrapperMapping!.addPropertyMapping(RKRelationshipMapping(fromKeyPath: "text", toKeyPath: "app_text", with: textMapping))
wrapperMapping!.addPropertyMapping(RKRelationshipMapping(fromKeyPath: "image", toKeyPath: "app_image", with: imageMapping))
wrapperMapping!.addPropertyMapping(RKRelationshipMapping(fromKeyPath: "quote", toKeyPath: "app_quote", with: quoteMapping))

articleMapping!.addPropertyMapping(RKRelationshipMapping(fromKeyPath: "article_details", toKeyPath: "details", with: wrapperMapping))

现在一切正常。

谢谢。

-N

【讨论】：