How to use singleton with Alamofire using Swift 3?

Question

I am new in iOS and I am bit confused that how to use singleton with Alamofire and how singleton is important. I created a networkWrapper class in that I have written Alamofire post and get method, but I didn't use singleton.

How can I create a Wrapper class of Alamofire with singleton? How can I get all tricks that is really important?

Below is my code for wrapper class:

import Foundation
import UIKit
import Alamofire
import SwiftyJSON

class AFWrapper: NSObject {

//TODO :-
/* Handle Time out request alamofire */


 class func requestGETURL(_ strURL: String, success:@escaping (JSON) -> Void, failure:@escaping (Error) -> Void)
    {
        Alamofire.request(strURL).responseJSON { (responseObject) -> Void in
            //print(responseObject)
            if responseObject.result.isSuccess {
                let resJson = JSON(responseObject.result.value!)
                //let title = resJson["title"].string
                //print(title!)
                success(resJson)
            }

        if responseObject.result.isFailure {
            let error : Error = responseObject.result.error!
            failure(error)
        }
    }
  }

static func requestPOSTURL(_ strURL : String, params : [String : AnyObject]?, headers : [String : String]?, success:@escaping (JSON) -> Void, failure:@escaping (Error) -> Void){
    Alamofire.request(strURL, method: .post, parameters: params, encoding: JSONEncoding.default, headers: headers).responseJSON { (responseObject) -> Void in
        //print(responseObject)
        if responseObject.result.isSuccess {
            let resJson = JSON(responseObject.result.value!)
            success(resJson)
        }
        if responseObject.result.isFailure {
            let error : Error = responseObject.result.error!
            failure(error)
        }
    }
  }
}

In my controller:

           if newLength == 6
            {
                let textZipCode = textField.text! + string

                let dict = ["id" : "43","token": "2y103pfjNHbDewLl9OaAivWhvMUp4cWRXIpa399","zipcode" : textZipCode] as [String : Any]

                //Call Service
               AFWrapper.requestPOSTURL(HttpsUrl.Address, params: dict as [String : AnyObject]?, headers: nil, success: { (json) in
                    // success code
                    print(json)
                }, failure: { (error) in
                    //error code
                    print(error)
                })


                setFields(city: "Ajmer", state: "Rajasthan", country: "India")
                return newLength <= 6
            }

score 6 · Answer 1 · answered Dec 21 '16 at 11:16

6

I didn't look deep into your code. In swift we can create singleton by

static let sharedInstance = AFWrapper()

And it will create singleton instance of a class, so that class and static for singleton class instance functions are not necessary. Please refer below code for singleton class.

import Foundation
import UIKit
import Alamofire
import SwiftyJSON

class AFWrapper: NSObject {

    static let sharedInstance = AFWrapper()

    //TODO :-
    /* Handle Time out request alamofire */


    func requestGETURL(_ strURL: String, success:@escaping (JSON) -> Void, failure:@escaping (Error) -> Void)
    {
        Alamofire.request(strURL).responseJSON { (responseObject) -> Void in
            //print(responseObject)
            if responseObject.result.isSuccess {
                let resJson = JSON(responseObject.result.value!)
                //let title = resJson["title"].string
                //print(title!)
                success(resJson)
            }

            if responseObject.result.isFailure {
                let error : Error = responseObject.result.error!
                failure(error)
            }
        }
    }

    func requestPOSTURL(_ strURL : String, params : [String : AnyObject]?, headers : [String : String]?, success:@escaping (JSON) -> Void, failure:@escaping (Error) -> Void){
        Alamofire.request(strURL, method: .post, parameters: params, encoding: JSONEncoding.default, headers: headers).responseJSON { (responseObject) -> Void in
            //print(responseObject)
            if responseObject.result.isSuccess {
                let resJson = JSON(responseObject.result.value!)
                success(resJson)
            }
            if responseObject.result.isFailure {
                let error : Error = responseObject.result.error!
                failure(error)
            }
        }
    }
}

Now you can call Singleton class instance function by

AFWrapper.sharedInstance.requestPOSTURL(HttpsUrl.Address, params: dict as [String : AnyObject]?, headers: nil, success: { (json) in
    // success code
    print(json)
}, failure: { (error) in
    //error code
    print(error)
})

answered Dec 21 '16 at 11:16

Vinupriya Arivazhagan

564
3
12

That's it right? Actually first time I am using singleton. And wanted to know why it is better ? Thanks – Kishor Pahalwani Dec 21 '16 at 11:22
You are welcome. If you find this useful, please accept this answer. So that others can refer. – Vinupriya Arivazhagan Dec 21 '16 at 11:24
May I know why singleton is better Please clear my doubts ? Thanks – Kishor Pahalwani Dec 21 '16 at 11:25
1

Its all depends on your need. There is pros and cons in both singleton and static classes. please refer this http://stackoverflow.com/questions/519520/difference-between-static-class-and-singleton-pattern – Vinupriya Arivazhagan Dec 21 '16 at 11:31
Yeah I wanted to know why can't we use static functions instead of singleton. thanks – Kishor Pahalwani Dec 21 '16 at 11:36
1

We can use static classes also. It all our need. I am using static classes only. By looking into your code, I can say you too can use static classes. – Vinupriya Arivazhagan Dec 21 '16 at 11:42
@VinupriyaArivazhagan this creates a memory leak, any idea how to fix that? – Saoud Rizwan Jan 31 '17 at 12:13
@SaoudRizwan How you checked the memory leak? and where it created problem? can u please give me some detailed information – Vinupriya Arivazhagan Feb 01 '17 at 06:58
@VinupriyaArivazhagan In instruments, it says the cause of the leak is Alamofire's Session.init function... that's really all the info it gives about it – Saoud Rizwan Feb 01 '17 at 17:21
{ "status" : "Bad Request", "statusDesc" : "FAILURE", "statusCode" : 400, "descrption" : "Mobile Number Does't Match,please try again.." } this is my json result but how can i write success and failure condition here for moving to next controller – Anil Oct 25 '17 at 05:20

Amanpreet · Answer 2 · 2016-12-21T11:09:28.027

1

May be you need that :

import UIKit
import Alamofire

struct FV_API
{
    //URL is http://www.stack.com/index.php/signup
    static let appBaseURL = ""  // assign your base url suppose:  http://www.stack.com/index.php
    static let apiSignUP = ""   // assign signup i.e: signup
}

class APIManager: NSObject
{
    //MARK:- POST APIs
    class func postAPI(_ apiURl:String, parameters:NSDictionary, completionHandler: @escaping (_ Result:AnyObject?, _ Error:NSError?) -> Void)
    {
        var strURL:String = FV_API.appBaseURL  // it gives http://www.stack.com/index.php and apiURl is apiSignUP

        if((apiURl as NSString).length > 0)
        {
            strURL = strURL + "/" + apiURl    // this gives again http://www.stack.com/index.php/signup 
        }

        _ = ["Content-Type": "application/x-www-form-urlencoded"]

        print("URL -\(strURL),parameters - \(parameters)")

      let api =  Alamofire.request(strURL,method: .post, parameters: parameters as? [String : AnyObject], encoding: URLEncoding.default)

        // ParameterEncoding.URL
        api.responseJSON
            {
                response -> Void in

                print(response)

                if let JSON = response.result.value
                {
                    print("JSON: \(JSON)")
                    completionHandler(JSON as AnyObject?, nil)
                }
                else if let ERROR = response.result.error
                {
                    print("Error: \(ERROR)")
                    completionHandler(nil, ERROR as NSError?)
                }
                else
                {
                    completionHandler(nil, NSError(domain: "error", code: 117, userInfo: nil))
                }
        }
    }

In other NSObject I made that method i.e for Signup:

class SignUp: NSObject
{
    class func registerWithAPI(firstName: String, lastName:String, completionHandler: @escaping (_ Result:AnyObject?, _ Error:NSError?) -> Void)
    {
        let dict = NSMutableDictionary()

        if !firstName.isEmpty
        {
           dict.setValue(firstName, forKey: "firstname")
        }
        if !lastName.isEmpty
        {
            dict.setValue(lastName, forKey: "lastname")
        }

        APIManager.postAPI(FV_API.apiSignUP, parameters: dict)
        {
            (Result, Error) -> Void in
            completionHandler(Result, Error)
        }
    }
}

In controller class I made method to call api like:

func apiForSignup()
    {
        SignUp.registerWithAPI(firstName: txtFieldFirstName.text!, lastName: txtFieldLastName.text!)
        {
            (Result, Error) -> Void in
            // write code
}

edited Dec 21 '16 at 11:09

answered Dec 21 '16 at 10:28

Amanpreet

1,301
3
12
29

Ok let me check this. Thanks – Kishor Pahalwani Dec 21 '16 at 10:35
Please check my updated question where I am calling service. Thanks – Kishor Pahalwani Dec 21 '16 at 10:43
Can you please elaborate your problem? In controller you wrote APIManager.apiPost() but your NSObject class name is AFWrapper.If you are using my answer then please follow all the steps. – Amanpreet Dec 21 '16 at 10:48
My problem is I am not getting the response. – Kishor Pahalwani Dec 21 '16 at 10:52
Error Domain=Alamofire.AFError Code=4 "JSON could not be serialized because of error: The data couldn’t be read because it isn’t in the correct format." – Kishor Pahalwani Dec 21 '16 at 10:53
Did you hit your API on Restclient or postman ? Is it working fine there? – Amanpreet Dec 21 '16 at 10:53
Please use the exact POST method as I wrote. – Amanpreet Dec 21 '16 at 10:56
OK but I am confused in it. I will try. – Kishor Pahalwani Dec 21 '16 at 11:04
And how can we create singleton in wrapper class. Actually I am new so please tell me. Thanks' – Kishor Pahalwani Dec 21 '16 at 11:04
I have edited my answer with pragma marks please follow that. And if confuse you can assign static complete url for the time being. – Amanpreet Dec 21 '16 at 11:11
Ok Thanks I will let you know. – Kishor Pahalwani Dec 21 '16 at 11:12
What is that appBaseURL = "" and apiSignUP I have separate class of HttpUrl and in that all url are present? Thanks – Kishor Pahalwani Dec 21 '16 at 11:14
Then use that make sure your url is correct. Print it where you fetch in code. – Amanpreet Dec 21 '16 at 11:15
1

check this to know more https://cocoacasts.com/what-is-a-singleton-and-how-to-create-one-in-swift/ – Amanpreet Dec 21 '16 at 11:41
OK I will check it. Thanks – Kishor Pahalwani Dec 21 '16 at 11:45

score 0 · Answer 3 · answered Apr 04 '19 at 11:38

Updated for Swift 4

import UIKit
import Alamofire
import SwiftyJSON
//
// MARK:- ipv6 Configuration...
//
private var webView = UIWebView(frame: CGRect.zero)
private var secretAgent: String? = webView.stringByEvaluatingJavaScript(from: "navigator.userAgent")
var authHeaders: HTTPHeaders = ["User-Agent": secretAgent!, "Content-Type": "application/json; charset=utf-8"]

class ApiManager: NSObject {

    static let sharedInstance = ApiManager()

    func requestGETURL(_ strURL: String, success:@escaping (JSON) -> Void, failure:@escaping (Error) -> Void) {

        Alamofire.request(strURL).responseJSON { (responseObject) -> Void in

            if responseObject.result.isSuccess, let resJson = responseObject.result.value {
                success(JSON(resJson))
            }

            if responseObject.result.isFailure {
                let error : Error = responseObject.result.error!
                failure(error)
            }
        }
    }

    func requestPOSTURL(_ strURL: String, params: [String : Any]?, headers: [String : String]?, success:@escaping (JSON) -> Void, failure:@escaping (Error) -> Void) {

        Alamofire.request(strURL, method: .post, parameters: params, encoding: JSONEncoding.default, headers: authHeaders).responseJSON { (responseObject) -> Void in

            if responseObject.result.isSuccess, let resJson = responseObject.result.value {
                success(JSON(resJson))
            }

            if responseObject.result.isFailure {
                let error : Error = responseObject.result.error!
                failure(error)
            }
        }
    }
}

How to use singleton with Alamofire using Swift 3?

3 Answers3