ios - Crashing when trying to pull image from URL with Swift

Question

I am saving the image url successfully from an api and am having issues showing it when I run the app. avatarString has the correct url but as soon as I get to the next line I keep getting:

fatal error: unexpectedly found nil while unwrapping an Optional value

My avatarData var is returning as nil. I don't know what why. Running Xcode Beta 6.3. Thanks for any help.

    dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), {

        var avatarString = NSURL(string: self.userInfo.avatarURL)!


        var avatarData = NSData(contentsOfURL: avatarString, options: nil, error: nil)

        var avatarImage = UIImage(data: avatarData!)

        self.avatarImage.image = avatarImage

    })

Answer 1

Always do UI related work(setting ImageView image etc) in Main queue And heavy works like downloading data ,do off the main queue, try like this:

 if let avatarString = NSURL(string: self.userInfo.avatarURL) {
            dispatch_async(dispatch_get_global_queue(Int(QOS_CLASS_USER_INITIATED.value), 0)){

                let imageData = NSData(contentsOfURL: avatarString)
                dispatch_async(dispatch_get_main_queue()) {
                    if imageData != nil {
                        self.avatarImage?.image = UIImage(data: imageData!)

                    }
                }
            }
        }

May be it helps.