Bolts-iOSのとっても簡単な使い方説明 ref: http://qiita.com/morizotter/items/8fcd8017b938927f6c4a

file0.txt

pod 'Bolts', '~> 1.1'

file1.txt

pod install

file2.txt

#import <Bolts.h>

file3.swift

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // PREPARE EMPTY TASK - FOR EXECUTING TASKS IN SERIES

        var task = BFTask(result: nil)

        // 1. ASYNCRONOUS CONNECTION TO YAHOO
        task = task.continueWithBlock({ (task: BFTask!) -> BFTask! in

            // INSTANTIATE TASK COMPLETION

            let taskCompletion = BFTaskCompletionSource()

            // ASYNCRONOUS NETWORK ACTIVITY

            let url = "http://yahoo.co.jp"
            let session = NSURLSession.sharedSession()
            let sessionTask = session.dataTaskWithURL(NSURL(string: url), completionHandler: { (data: NSData!, response: NSURLResponse!, error: NSError!) -> Void in

                if let err = error {
                    println("1 ERROR: YAHOO!")
                    taskCompletion.setError(err)
                }
                println("1 SUCCESS: YAHOO!")
                taskCompletion.setResult(data)
            })
            sessionTask.resume()

            // RETURN TASK

            return taskCompletion.task
        })

        // 2. ASYNCRONOUS CONNECTION TO GOOGLE
        task = task.continueWithBlock({ (task: BFTask!) -> BFTask! in

            // INSTANTIATE TASK COMPLETION

            let taskCompletion = BFTaskCompletionSource()

            // ASYNCRONOUS NETWORK ACTIVITY

            let url = "http://google.com"
            let session = NSURLSession.sharedSession()
            let sessionTask = session.dataTaskWithURL(NSURL(string: url), completionHandler: { (data: NSData!, response: NSURLResponse!, error: NSError!) -> Void in

                if let err = error {
                    println("2 ERROR: GOOGLE!")
                    taskCompletion.setError(err)
                }
                println("2 SUCCESS: GOOGLE!")
                taskCompletion.setResult(data)
            })
            sessionTask.resume()

            // RETURN TASK

            return taskCompletion.task
        })
    }
}