async_await.swift

//
//  ViewController.swift
//  Promise
//
//  Created by 默司 on 2016/10/12.
//  Copyright © 2016年 默司. All rights reserved.
//

import UIKit
import PromiseKit
import AwaitKit

class ViewController: UIViewController {

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

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

    func request(url: String) -> Promise<Data?> {
        return Promise { (resolve, reject) in
            URLSession.shared.dataTask(with: URL(string: url)!) {data,res,error in
                if let error = error {
                    return reject(error)
                }
                
                resolve(data)
            }.resume()
        }
    }
    
    func stop(sec: Int) -> Promise<Void> {
        return Promise(resolvers: { (resolve, _) in
            DispatchQueue.global().asyncAfter(deadline: .now() + .seconds(sec)) {
                resolve()
            }
        })
    }

    @IBAction func asyncWork(_ sender: AnyObject) {
        async {
            print("start")
            
            do {
                try await(self.stop(sec: 5))
                
                let data = try await(self.request(url: "https://news.baidu.com/"));
                
                print("end")
                print("============")
                print(data)
                print("============")
            } catch {
                print(error)
            }
        }
    }
    
    @IBAction func anotherWork(_ sender: AnyObject) {
        print("click!")
    }
}