Sharing Extension in IOS8 beta

Question

I\'m trying to create a sharing extension using the new iOS 8 app extensions. I tried to get the current URL of a Safari site to show it in a UILabel. Simple enough.

Answer 1

All of those previous answers are really good but I just came accross this issue in Swift and felt it was a little tidious to extract the URL from a given NSExtensionContext especially in the CFString to String conversion process and the fact that the completionHandler in loadItemForTypeIdentifier is not executed in the main thread.

import MobileCoreServices

extension NSExtensionContext {
  private var kTypeURL:String {
      get {
          return kUTTypeURL as NSString as String
      }
  }

  func extractURL(completion: ((url:NSURL?) -> Void)?) -> Void {
      var processed:Bool = false

      for item in self.inputItems ?? [] {
          if  let item = item as? NSExtensionItem,
              let attachments = item.attachments,
              let provider = attachments.first as? NSItemProvider
              where provider.hasItemConformingToTypeIdentifier(kTypeURL) == true {
                  provider.loadItemForTypeIdentifier(kTypeURL, options: nil, completionHandler: { (output, error) -> Void in
                      dispatch_async(dispatch_get_main_queue(), { () -> Void in
                          processed = true
                          if let url = output as? NSURL {
                              completion?(url: url)
                          }
                          else {
                              completion?(url: nil)
                          }
                      })

                  })
          }
      }

      // make sure the completion block is called even if no url could be extracted
      if (processed == false) {
          completion?(url: nil)
      }
  }
}

That way you can now simply use it like this in your UIViewController subclass:

self.extensionContext?.extractURL({ (url) -> Void in
    self.urlLabel.text = url?.absoluteString
    println(url?.absoluteString)
})