从http请求中快速检索json数据

Question

I'm new to swift and thus the question. I want to wrap my http calls into a function of this signature.

func httpPost()-> Any

This code works but how can I wrap this code in the functio signature I want.

let headers = [
    "Content-Type": "application/json",
    "cache-control": "no-cache"
]
let parameters = [
    "client_id": "xxx",
    "client_secret": "yyy"
    ] as [String : Any]

let postData = try? JSONSerialization.data(withJSONObject: parameters, options: [])

var request = URLRequest(url: URL(string: "http://xxx.xxx")! as URL,
                                  cachePolicy: .useProtocolCachePolicy,
                                  timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData

let session = URLSession.shared
let dataTask = session.dataTask(with: request) { (data, response, error) -> Void in
    guard let data = data else {return}
    do{
        try validate(response)
        let json = try JSONSerialization.jsonObject(with: data, options: [])

    }catch{
        print(error)
    }
    //print(String(describing: data))
}

dataTask.resume()

I want to return the json object as Any here

Answer 1

You can't return a direct value in an asynchronous function until you block the thread which is a bad idea , so you want a completion

func httpPost(completion:@escaping(_ ret:Any?,err:Error?) -> Void)

    let headers = [
        "Content-Type": "application/json",
        "cache-control": "no-cache"
    ]
    let parameters = [
        "client_id": "xxx",
        "client_secret": "yyy"
        ] as [String : Any]

    let postData = try? JSONSerialization.data(withJSONObject: parameters, options: [])

    var request = URLRequest(url: URL(string: "http://xxx.xxx")! as URL,
                                      cachePolicy: .useProtocolCachePolicy,
                                      timeoutInterval: 10.0)
    request.httpMethod = "POST"
    request.allHTTPHeaderFields = headers
    request.httpBody = postData

    let session = URLSession.shared
    let dataTask = session.dataTask(with: request) { (data, response, error) -> Void in
        guard let data = data else {
          completion(nil,error)
          return
        }
        do{
            try validate(response)
            let json = try JSONSerialization.jsonObject(with: data, options: [])
            completion(json,nil)

        }catch{
            print(error)
            completion(nil,error)
        }
        //print(String(describing: data))
    }

    dataTask.resume()
}

---

To call

httpPost { (json,error) in
   print(json)
}

also it's better to cast the json as [Any] / [String:Any] for Array/ Dictionary response respectively