Swift(or objective-c) equivalent of curl request

Question

I'd like to maniplate the following curl request into swift(or objective-c).

curl -X POST \ -d "login_id=mylogin_id" \ 
-d "api_key=myapi_key" \ 
https://~~~~~/v2/authenticate/api

The following is what I wrote.

func authentication(){
    var loginID = "mylogin_id"
    var apiKey = "myapi_key"
    var post:NSString = "login_id=\(loginID)&api_key=\(apiKey)"

    NSLog("PostData: %@",post);

    var url:NSURL = NSURL(string:"https://~~~~~/v2/authenticate/api")!

    var postData:NSData = post.dataUsingEncoding(NSASCIIStringEncoding)!

    var postLength:NSString = String( postData.length )

    var request:NSMutableURLRequest = NSMutableURLRequest(URL: url)
    request.HTTPMethod = "POST"
    request.HTTPBody = postData
    request.setValue(postLength, forHTTPHeaderField: "Content-Length")
    request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
    request.setValue("application/json", forHTTPHeaderField: "Accept")


    var reponseError: NSError?
    var response: NSURLResponse?

    var urlData: NSData? = NSURLConnection.sendSynchronousRequest(request, returningResponse:&response, error:&reponseError)
}

If the login is successful a token will be returned, however, I cannot get it.

{"auth_token": "ea6d13c7bc50feb46cf978d137bc01a2"}

I referred this link . Thank you for your kindness.

////// ※Update Jan4th PM2:30

I have rewritten the code from "var request~~" as following, then get "Error", therefore it looks like this code returns urlData as nil.

If you will find how to solve problem, please help me.

var request:NSMutableURLRequest = NSMutableURLRequest(URL: url)
    request.HTTPMethod = "POST"
    request.HTTPBody = postData
    //request.setValue(postLength, forHTTPHeaderField: "Content-Length")
    request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
    //request.setValue("application/json", forHTTPHeaderField: "Accept")

    var reponseError: NSError?
    var response: NSURLResponse?
    var urlData: NSData? = NSURLConnection.sendSynchronousRequest(request, returningResponse:&response, error:&reponseError)
    if (urlData != nil){
        var responseData:NSString  = NSString(data:urlData!, encoding:NSUTF8StringEncoding)!
        let res = response as NSHTTPURLResponse!;

        NSLog("Response code: %ld", res.statusCode);

        if (res.statusCode >= 200 && res.statusCode < 300){
            var responseData:NSString  = NSString(data:urlData!, encoding:NSUTF8StringEncoding)!

            NSLog("Response ==> %@", responseData);
        }
    }else{
        NSLog("Error");
    }

Answer 1

I've got the auth token by using NSURLSession on behalf of NSURLConnection, however I am still not sure why NSURLSession can be used and NSURLConnection cannot be used. If you have an idea, please tell me. Thank you for your kindness.

func authentication2(){
    let request = NSMutableURLRequest(URL: NSURL(string: "https://~~~/v2/authenticate/api")!)
    request.HTTPMethod = "POST"

    var loginID = "mylogin_id"
    var apiKey = "myapi_key"
    var postString:NSString = "login_id=\(loginID)&api_key=\(apiKey)"

    request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)
    let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
        data, response, error in

        if error != nil {
            println("error=\(error)")
            return
        }

        println("response = \(response)")

        let responseString = NSString(data: data, encoding: NSUTF8StringEncoding)
        println("responseString = \(responseString)")
    }
    task.resume()
}