REF: Script#

Will we finally have a decent scripting language on our browsers?

The latest release of Script# (0.2.0.0), also published today, contains a code-behind model that allows me to add c# code-behind to a page, and have that converted into script. I'll blog more about that in the coming days, but this post is mostly about WPF/E.

Here is a portion of my Scriptlet class, which contains c# code-behind for the page. The code in bold shows the scriptlet instantiating a WPF/E plugin instance with some XAML markup.

using System;
using System.DHTML;
using System.WPFE;
using ScriptFX.UI;

namespace PhotoViewer {

   public sealed class PhotoViewerScriptlet : IDisposable {
       private PhotoViewerControl _photoViewerControl;
       ...

       public static void Main(Dictionary arguments) {
           PhotoViewerScriptlet scriptlet = new PhotoViewerScriptlet(arguments);
       }

       private PhotoViewerScriptlet(Dictionary arguments) {
           ...
           Button searchButton = new Button((DOMElement)arguments["SearchButtonElement"]);
           searchButton.Click += OnSearchLinkClick;

           WPFEPlayer player =
               WPFEFactory.CreateWPFEPlayer((string)arguments["ID"],
                                            (DOMElement)arguments["ParentElement"],
                                            (string)arguments["MarkupURL"],
                                            "Black", /* windowLess */ true);
           _photoViewerControl =
               new PhotoViewerControl(player, (string)arguments["FlickrKey"]);
           ...
       }

       private void OnSearchLinkClick(object sender, EventArgs e) {
           string[] tags = _tagsTextBox.Text.Trim().Split(' ');
           _photoViewerControl.Start(tags);
       }

       ...
   }
}

And here is some code from the PhotoViewerControl that wraps the WPF/E plugin and implements the functionality to make requests to Flickr and progress the presentation from one photo to the next.

internal sealed class PhotoViewerControl : IDisposable {

   private WPFEPlayer _player;
   private string _flickrKey;

   private Image _photo1;
   private TextBlock _title1;
   private Storyboard _storyboard1;

   private HTTPRequest _request;

   private Photo[] _photos;
   private int _nextPhoto1;

   public PhotoViewerControl(WPFEPlayer player, string flickrKey) {
       _player = player;
       _flickrKey = flickrKey;
   }

   public void Initialize() {
       _photo1 = (Image)_player.FindName("image1");
       _title1 = (TextBlock)_player.FindName("title1");
       _storyboard1 = (Storyboard)_player.FindName("storyboard1");
       ...
   }

   public void Start(string[] tags) {
       Dictionary scriptTransportParams = new Dictionary();
       scriptTransportParams["callbackParameterName"] = "jsoncallback";

       string uri = String.Format(FlickrSearchURLFormat, _flickrKey, tags.Join("+"));
       uri = HTTPTransport.CreateURI(uri, typeof(ScriptTransport), scriptTransportParams);

       _request = HTTPRequest.CreateRequest(uri, HTTPVerb.GET);
       _request.Invoke(OnRequestComplete, null);
   }

   private void OnRequestComplete(HTTPRequest request, object userContext) {
       IHTTPResponse response = request.Response;

       if (response.StatusCode == HTTPStatusCode.OK) {
           PhotoSearchResponse searchResponse = (PhotoSearchResponse)response.GetObject();
           _photos = searchResponse.photos.photo;
           StartInternal();
       }
   }

   private static string CreateFlickrPhotoURL(Photo photo) {
       return String.Format(FlickrPhotoURLFormat, photo.server, photo.id, photo.secret);
   }

   private void ShowFirstPhoto() {
       _photo1.Source = CreateFlickrPhotoURL(_photos[_nextPhoto1]);
       _title1.Text =  _photos[_nextPhoto1].title;
       Window.SetTimeout(StartFirstTimeline, 1000);

       _nextPhoto1 += 2;
       if (_nextPhoto1 >= _photos.Length) {
           _nextPhoto1 = 0;
       }
   }

   private void StartInternal() {
       _nextPhoto1 = 0;

       ShowFirstPhoto();
       Window.SetTimeout(ShowSecondPhoto, 8000);
   }

   private void StartFirstTimeline() {
       _storyboard1.Begin();
       Window.SetTimeout(ShowFirstPhoto, 14000);
   }
   ...
}

One other thing to observe in the sample... the sample makes requests to the Flickr service directly without going through a server-side proxy. To make these cross-domain calls successfully, It uses

<script>

tags rather than XMLHttp to work against Flickr, and uses the JSONP support provided by the service. Script# provides a mechanism to work against this protocol transparently by hiding away the plumbing in the ScriptTransport class that is referenced in the code above. If this is of interest, drop me a comment, and I'll blog about it further.

The sample is packaged into the Script# msi that you can download to delve into the code. In addition to this sample, the msi contains the Script# compiler, and various other samples. There is also a document with a how-to guide on using Script# with a lot of new content, that should help you get up and running using the installed project templates.

in: nikhilt.net