ios - Facebook iOS SDK 和 Swift - 如何创建依赖批处理请求？

Question

当第二个(子)请求依赖于第一个(父)请求时，我正在尝试弄清楚如何编写 FB Graph API 请求(FB SDK 4.0 和 Swift)。具体来说，我想获得用户的相册和每张相册的封面照片。

1. me/albums?fields=name,cover_photo <-- 获取用户相册请求

2. /888474748 <-- 获取封面照片请求

关于 FBSDKGraphRequestConnection 的文档和 API 文档非常模糊提到方法 addRequest:completionHandler:batchParameters: 可以接受诸如“name”和“depends_on”之类的参数。这似乎是我正在寻找的方法，但我可以找到它在 Obj-C 或 Swift 中的使用示例。

它应该看起来像这样吗？谢谢!

 let albumRequest = FBSDKGraphRequest(graphPath: "me/albums?fields=name,cover_photo", parameters: nil)
    let albumCoverRequest = FBSDKGraphRequest(graphPath: "cover_photo_id", parameters: nil) //what should this look like? jsonpath?
    let graphConnection = FBSDKGraphRequestConnection()
    graphConnection.addRequest(albumRequest, completionHandler: { (connection:FBSDKGraphRequestConnection!, result:AnyObject!, error:NSError!) -> Void in
        if(error != nil){
            println(error)
        }else{

        }
        },batchParameters: ["name" : "albums"])

    graphConnection.addRequest(albumRequest, completionHandler: { (connection:FBSDKGraphRequestConnection!, result:AnyObject!, error:NSError!) -> Void in
        if(error != nil){
            println(error)
        }else{

        }
        },batchParameters: ["depends_on" : "albums"]) //should this be some jsonpath expression?

Answer 1

明白了。

let albumRequest = FBSDKGraphRequest(graphPath: "me/albums?fields=name,cover_photo", parameters: nil)
    let albumCoverRequest = FBSDKGraphRequest(graphPath: "?ids={result=albums:$.data.*.cover_photo}", parameters: nil) // use jsonpath syntax to "inject" parent results into "child" request
    let graphConnection = FBSDKGraphRequestConnection()
    graphConnection.addRequest(albumRequest, completionHandler: { (connection:FBSDKGraphRequestConnection!, result:AnyObject!, error:NSError!) -> Void in
        if(error != nil){
            println(error)
        }else{
            println(result)
        }
        },batchParameters: ["name" : "albums"]) //Set "parent" batch alias

    graphConnection.addRequest(albumCoverRequest, completionHandler: { (connection:FBSDKGraphRequestConnection!, result:AnyObject!, error:NSError!) -> Void in
        if(error != nil){
            println(error)
        }else{
            println(result)
        }
        },batchParameters: ["depends_on" : "albums"]) //depend on parent batch alias
    graphConnection.start()