Swift Alamofire SwiftyJSON Asynchronous/Synchronous Class Methods

Question

So I currently have the following:

class ViewController: UIViewController {

class Identity{
    let baseUrl = "superSecretURL"
    var _username: String = ""
    var _password: String = ""
    var _apiKey: String = ""

    init(){

    }

    init(username: String, apiKey: String){
        _username = username
        _apiKey = apiKey
    }

    init(username: String, password: String){
        _username = username
        _password = password
    }

    func loginPassword() -> String{
        var loginJSON = ["auth": ["passwordCredentials": ["username": _username, "password": _password]]];
        var returnJSON: String

        request(.POST, baseUrl, parameters: loginJSON, encoding: .JSON)
            .responseJSON { (request, response, data, error) in
                if let anError = error
                {
                    // got an error in getting the data, need to handle it
                    println("error calling POST on /posts")
                    println(error)
                }
                else if let data: AnyObject = data
                {
                    // handle the results as JSON, without a bunch of nested if loops
                    let post = JSON(data)
                    // to make sure it posted, print the results
                    println("JSON Returned")
                }
        }
    }
}

var i = Identity(username: "secretName", password: "complicatedPassword")

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    println("Before Call")



    println("After Call")

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


}

Basically I would like to be able to call the println("Before Call") then receive a response from the loginPassword() method and then println("After Call"). This is I believe synchronous but I can't figure out a way to get it to work and the whole threads thing has baffled my head.

I basically want to be able to say:

if i.loginPassword(){ // do some login stuff }else{ // do some error stuff }

Any help or pointers appreciated.

Hugo Alonso · Accepted Answer · 2016-06-10T14:27:53.083

You need to set a callback function to be called whenever you want inside your loginPassword() function.

This could be a way of achieving it:

func loginPassword(callback: ((isOk: Bool)->Void)?) -> String{
 var loginJSON = ["auth": ["passwordCredentials": ["username": _username, "password": _password]]];
 var returnJSON: String

 request(.POST, baseUrl, parameters: loginJSON, encoding: .JSON)
   .responseJSON { (request, response, data, error) in
      if let anError = error{
       // got an error in getting the data, need to handle it
        println("error calling POST on /posts")
        println(error)

        callback?(isOk: false)
      }
      else if let data: AnyObject = data{
      // handle the results as JSON, without a bunch of nested if loops
        let post = JSON(data)
       // to make sure it posted, print the results
        println("JSON Returned")

        callback?(isOk: true)
      }
    }
}

and then...

override func viewDidLoad() {
    super.viewDidLoad()

    var identity = Identity(username: "John Apleseed", apiKey: "213123123")

    identity.loginPassword { (isOK) -> Void in
        if (isOK) {
            //do good stuff here
        }else{
           // do error handling here
        }

    }
}

UPDATE

Also, your calling function can look like this:

override func viewDidLoad() {
    super.viewDidLoad()

    var identity = Identity(username: "John Apleseed", apiKey: "213123123")
    identity.loginPassword(handlePasswordRequest)
}

and you can add as many callback handlers as you may need without messing around with a bunch of nested closures...

private func handlePasswordRequest(isOK: Bool){
    if (isOK) {
        //do good stuff here
    }else{
        // do error handling here
    }
}

UPDATE 2

If you are in need to call a callback deep into the hierarchy of calls, then you will need to pass the callback as a parameter of every previous closures.

UPDATE 3

I would give a try to RxAlamofire and all about RxSwift

Brilliant thanks! Is there a way to chain this together using promises so it doesn't look quite as nasty with nesting? This could potentially get 4-5 levels deep during the other half of the application? — Alex Bailey, May 12 '15 at 20:52
Do you know how the original answer looks in Swift 2? It worked for me in swift 1.2 but now the error parameter seems to be removed. [Here](http://stackoverflow.com/questions/32277680/alamofire-post-request-with-swift-2) is my question about this — mattgabor, Aug 28 '15 at 18:36
@HugoAlonso I would love to see RxAlamofire Nesting of Callback example. Could you provide a gist for this? Thanks! — user805981, Aug 11 '16 at 02:55

Swift Alamofire SwiftyJSON Asynchronous/Synchronous Class Methods

1 Answers1