Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community!

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

iOS Build a Weather App with Swift (Retired) Concurrency Using Our JSON Data

Posted by Rolando Cruz
Rolando Cruz
2,995 Points

"Cast from 'NSData?' to unrelated type 'NSDictionary' always fails"

I get that error with this code:

let baseURL = NSURL(string: "https://api.forecast.io/forecast/\(apiKey)/")
        let forecastURL = NSURL(string: "37.8267,-122.423", relativeToURL: baseURL)


        let sharedSession = NSURLSession.sharedSession()
        let downloadTask: NSURLSessionDownloadTask =
            sharedSession.downloadTaskWithURL(forecastURL!,
                completionHandler: { (location: NSURL!, response: NSURLResponse!, error: NSError!) -> Void in


                    if (error == nil) {
                    let dataObject = NSData(contentsOfURL: location)

                    let weatherDictionary: NSDictionary = NSJSONSerialization.dataWithJSONObject(dataObject!, options: nil, error: nil) as! NSDictionary
                    }

            })
        downloadTask.resume()

Chris Upjohn Pasan Premaratne Christian Andersson Adam Moore

Rolando Cruz
Rolando Cruz
2,995 Points

Chris Upjohn Pasan Premaratne Christian Andersson Adam Moore Amit Bijlani

Anthony Munoz
Anthony Munoz
1,935 Points
Anthony Munoz
Anthony Munoz
1,935 Points

let dataObject = NSData(contentsOfURL: location!) unwrap NSJSONSerialization.JSONObjectWithData not NSJSONSerialization.dataWithJSONObject