I am at a loss with this quiz. I create typealias BlogPostCompletion = (NSData!, NSURLResponse!, NSError!) -> Void

Just want to provide a link to the objective:

http://teamtreehouse.com/library/build-a-weather-app-with-swift-2/managing-complexity/callback-methods-with-closures

Here's the objective:

Challenge Task 1 of 2

We're writing an app to fetch the most recent blog posts from the Treehouse blog. This requires making a network request using asynchronous methods that execute in the background. For that we need a closure.

Create a method called fetchTreehouseBlogPosts, that has a single parameter - a completion handler. The closure has three parameters: a data object containing the results of the request as type NSData!, the HTTP response object from our request as type NSURLResponse!, an error object as type NSError!, and a return type of void.

Note: If you prefer to use a typealias to make the method signature clear, name it BlogPostCompletion

There is another forum post about this (which doesn't have many responses): https://teamtreehouse.com/forum/whats-wrong-on-this-syntax-in-swift

Notice though it says:

This requires making a network request using asynchronous methods that execute in the background

I don't think this code has anything asynchronous about it.

I found this swift code:

var url : String = "http://google.com?test=toto&test2=titi"
var request : NSMutableURLRequest = NSMutableURLRequest()
request.URL = NSURL(string: url)
request.HTTPMethod = "GET"

NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue(),

    completionHandler:{ (response:NSURLResponse!, data: NSData!, error: NSError!) -> Void in

})

..on this StackOverFlow page:

http://stackoverflow.com/questions/27720021/swift-cant-send-urlrequest-at-all

maybe there should be some code like that?

It's similar to code on this page:

https://gist.github.com/cmoulton/01fdd4fe2c2e9c8195e1

However, this code would have to be adapted to use the fetchTreehouseBlogPosts method somehow..

I would also note there is a TeamTreehouse blog post about making asynchronous network requests in Swift:

http://blog.teamtreehouse.com/making-network-request-swift

However, none of the code in that blog post seems to pass.

Looking at the NetworkOperations code in the course Downloads "Stormy3V2" zip file for the course,

I found a typealias line so I modified that code to conform with the questions and got:

class NetworkOperation {

    lazy var config: NSURLSessionConfiguration = NSURLSessionConfiguration.defaultSessionConfiguration()
    lazy var session: NSURLSession = NSURLSession(configuration: self.config)
    let queryURL: NSURL

    typealias BlogPostCompletion = ([String: AnyObject]? -> Void)

    init(url: NSURL) {
        self.queryURL = url
    }

    func fetchTreehouseBlogPosts(completion: BlogPostCompletion) {

        let request = NSURLRequest(URL: queryURL)
        let dataTask = session.dataTaskWithRequest(request) {
            (let data, let response, let error) in

            // 1. Check HTTP response for successful GET request
            if let httpResponse = response as? NSHTTPURLResponse {
                switch httpResponse.statusCode {
                case 200:
                    // 2. Create JSON object with data
                    let jsonDictionary = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: nil) as? [String: AnyObject]
                    completion(jsonDictionary)
                default:
                    println("GET request not successful. HTTP status code: \(httpResponse.statusCode)")
                }
            } else {
                println("Error: Not a valid HTTP response")
            }
        }

        dataTask.resume()
    }
}

However it didn't like that code either (although the output.html showed no errors), it still gave:

Bummer! Make sure the method is named fetchTreehouseBlogPosts and has the correct syntax!