NSURLConnection And NSURLSession

Apple has released NSURLSession APIs for iOS 7.0 onwards and it has made life a lot easier for us:

NSURLConnection Code
let queue: NSOperationQueue = …
let url = NSURL(string: “https://www.example.com”)!
let request = NSURLRequest(URL: url)
NSURLConnection.sendAsynchronousRequest(request, queue: queue) 
{
(response: NSURLResponse?, data: NSData?, error: NSError?) in
}



NSURLSession Code

let url = NSURL(string: “https://www.example.com”)!
let request = NSURLRequest(URL: url)
let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
(data: NSData?, response: NSURLResponse?, error: NSError?) in
…
}
task.resume()



Advantages of NSURLSession Over NSURLConnection:

– Fetching of data via network is easy
– Upload and download of data in the background
– Rich delegate methods
– Get the progress of loading, download, upload.
– Option to Cancel, Pause, Resume, Restart the download/upload network operations.
– Multiple session configurations to suit the application requirement
– Can provide different settings for different sessions.
– Private sessions, Cookies, Storage
– Support for HTTP1.1 and HTTP 2.0 automatically. No source code changes required.
– Uses best available connectivity (iPhone or WiFi)
– Switching to NSURLSession is easy
– Watch OS 2 only supports NSURLSession, It encourages reusability code in between iOS and Watch OS apps.
– Performance is better and well supported by Apple


Disadvantages of NSURLConnection:

– Watch OS2 does not support NSURLConnection
– Lot of coding is required
– Get the progress of loading, download, upload.