App Extension iOS9: How can I send a string / URL from the share view to my the app?

Question

Unfortunately, there's currently a lack of sample code oder proper information on App Extension / Share Sheets on iOS 9. (Even Apples Dev Support is very disappointing in this regard. Just today I got the answer "We don’t have an action extension sample either unfortunately". And they won't send me.

Anyway, maybe someone is willing to share his knowledge on this topic. So, adding a Share Extension in xcode is the easy part, but I struggle with

1. sending and receiving strings: I want the Share Sheet to open in Safari with the current URL (maybe even with the Character Counter like in the WWDC 2015 Video "App Extension Best Practices") and send it to the app by tapping "Post". Is it really necessary to open an NSURLSession?

2. adding an Share-icon under / General / "App Icons and Launch Images" / App Icons Source is not possible. Some Sources suggest to use Asset Catalog - but before I do, is there no other way to simply add ONE image?

Other Sources I found include:

Today Extension: raywenderlich.com/83809/ios-8-today-extension-tutorial

How to Build a Simple Action Extension: http://code.tutsplus.com/tutorials/ios-8-how-to-build-a-simple-action-extension--cms-22794

Basic Share Extensions with Data Sharing on iOS 8: http://www.andypierz.com/blog/2014/9/19/basic-share-extensions-with-data-sharing-on-ios-8

What I was able to accomplish so far is to add a title to the Share Sheet on shareViewController.m:

- (void)loadView
{
    [super loadView];
    self.title = @"Title of the Share Sheet";
}

Answer 1

I want the Share Sheet to open in Safari with the current URL (maybe even with the Character Counter like in the WWDC 2015 Video "App Extension Best Practices")

It is not up to you what app the user uses your share extension in, and it is not up to you what data that app supplies to the share extension. The app will share what the app wants to share. All you can do is define what kind of data you are willing to accept.

and send it to the app by tapping "Post"

When the user taps "Post", your didSelectPost override is called. What you do is up to you. What do you mean by "the app" here? Do you mean, your app that provides the share extension? Then devise a custom URL scheme for communication from the extension to the app, or use one of the other data sharing methods described in the docs:

https://developer.apple.com/library/ios/documentation/General/Conceptual/ExtensibilityPG/ExtensionScenarios.html

adding an Share-icon under / General / "App Icons and Launch Images" / App Icons Source is not possible. Some Sources suggest to use Asset Catalog - but before I do, is there no other way to simply add ONE image?

The icon for a share extension is automatically the icon of the app that supplies the share extension.

Answer 2

to extract the URL, you will have to enable the ExtensionPreprocessingJS part first

the following is slightly modified from AppCode iOS8 action extension tutorial

Add a new file GetURL.js to your share extension folder

var GetURL = function() {};

GetURL.prototype = {

   run: function(arguments) {
       arguments.completionFunction({ "currentUrl" : document.URL });
   }    
};

var ExtensionPreprocessingJS = new GetURL;

Next, you will have to edit your Info.plist so that the host app will call the JS. Refer to AppCode tutorial on how to do so.

Then include the following function in your ShareViewController viewDidLoad

    //swift code
    let extensionItem = extensionContext?.inputItems.first as! NSExtensionItem
    let itemProvider = extensionItem.attachments?.first as! NSItemProvider

    let propertyList = String(kUTTypePropertyList)
    if itemProvider.hasItemConformingToTypeIdentifier(propertyList) {
        itemProvider.loadItemForTypeIdentifier(propertyList, options: nil, completionHandler: { (item, error) -> Void in
            let dictionary = item as! NSDictionary
            NSOperationQueue.mainQueue().addOperationWithBlock {
                let results = dictionary[NSExtensionJavaScriptPreprocessingResultsKey] as! NSDictionary
                let url = NSURL(string: (results["currentURL"] as! String))                                        
                //now you can do what you like with this url
            }
        })
    } else {
        print("error")
    }