/BlogEngine/BlogEngine.NET/App_Code/Extensions/MediaElementPlayer.cs

/* 

Author: John Dyer (http://johndyer.name/)

Player: MediaElementJS (http://mediaelementjs.com/)

*/



using System;

using System.Text;

using System.Text.RegularExpressions;

using System.Collections;

using System.Collections.Generic;

using System.Web;

using System.Web.UI.HtmlControls;

using BlogEngine.Core;

using BlogEngine.Core.Web.Controls;

using BlogEngine.Core.Web.Extensions;

using Page=System.Web.UI.Page;



/// <summary>

/// Adds a HTML5 video/audio player to posts with Flash/Silverlight fallbacks

/// </summary>

[Extension("HTML5 Video/Audio Player", "1.5", @"<a href=""http://johndyer.me/"">John Dyer</a>")]

public class MediaElementPlayer

{



    #region Private members

    private const string _extensionName = "MediaElementPlayer";

    private static readonly object _syncRoot = new object();

    static protected Dictionary<Guid, ExtensionSettings> _blogsSettings = new Dictionary<Guid, ExtensionSettings>();

    #endregion



    private const int _widthDefault = 480;

    private const int _heightDefault = 360;

	private const bool _enableAutoSize = false;

    private const string _folderDefault = "media";



    /// <summary>

    /// Adds a Flash video player to the post.

    /// </summary>

    static MediaElementPlayer()

    {

        Post.Serving += Publishable_Serving;

        BlogEngine.Core.Page.Serving += Publishable_Serving;

        InitSettings();

    }



    private static void InitSettings()

    {

        // call Settings getter so default settings are loaded on application start.

        var s = Settings;

    }



    private static ExtensionSettings Settings

    {

        get

        {

            Guid blogId = Blog.CurrentInstance.Id;

            if (!_blogsSettings.ContainsKey(blogId))

            {

                lock (_syncRoot)

                {

                    if (!_blogsSettings.ContainsKey(blogId))

                    {

                        _blogsSettings[blogId] = LoadExtensionSettingsForBlogInstance();

                    }

                }

            }



            return _blogsSettings[blogId];

        }

    }



    private static ExtensionSettings LoadExtensionSettingsForBlogInstance()

    {

        ExtensionSettings initialSettings = new ExtensionSettings(_extensionName);

        initialSettings.Help = @"

<p>Build on <a href=""http://mediaelement.js.com/"">MediaElement.js</a>, the HTML5 video/audio player.</p>



<ol>

	<li>Upload media files to your /media/ folder</li>

	<li>Add short code to your media: [video src=""myfile.mp4""] for video and [audio src=""myfile.mp3""] for audio</li>

	<li>Customize with the following parameters:

		<ul>

			<li><b>width</b>: The exact width of the video</li>

			<li><b>height</b>: The exact height of the video</li>

			<li><b>autoplay</b>: Plays the video as soon as the webpage loads</li>

		</ul>

	</li>

	<li>You can also specify multiple file formats and codecs 

		<ul>

			<li><b>mp4</b>: H.264 encoded MP4 file</li>

			<li><b>webm</b>: VP8/WebM encoded file</li>

			<li><b>ogg</b>: Theora/Vorbis encoded file</li>

		</ul>

	</li>

</ol>



<p>A complete example:<br />

[code mp4=""myfile.mp4"" webm=""myfile.webm"" ogg=""myfile.ogg"" width=""480"" height=""360""]

</p>



<p>Supported formats</p>

<ul>

	<li><b>MP4/MP3</b>: Native HTML5 for IE9, Safari, Chrome; Flash in IE8, Firefox, Opera</li>

	<li><b>WebM</b>: HTML5 for IE9, Chrome, Firefox, Opera; Flash in IE8 (coming in Flash 11)</li>

	<li><b>FLV</b>: Flash fallback</li>

	<li><b>WMV/WMA</b>: Silverlight fallback</li>

</ul>

";

        initialSettings.IsScalar = true;





        initialSettings.AddParameter("width", "Default Width");

        initialSettings.AddValue("width", _widthDefault.ToString());



        initialSettings.AddParameter("height", "Default Height");

        initialSettings.AddValue("height", _heightDefault.ToString());



        initialSettings.AddParameter("folder", "Folder for Media (MP4, MP3, WMV, Ogg, WebM, etc.)");

        initialSettings.AddValue("folder", _folderDefault);



        return ExtensionManager.InitSettings(_extensionName, initialSettings);

    }



    private static void Publishable_Serving(object sender, ServingEventArgs e)

    {

        if (!ExtensionManager.ExtensionEnabled("MediaElementPlayer"))

            return;



        if (e.Location == ServingLocation.PostList || e.Location == ServingLocation.SinglePost || e.Location == ServingLocation.Feed || e.Location == ServingLocation.SinglePage) {

	

			HttpContext context = HttpContext.Current;			

	

			string regex = @"(video|audio)";

			List<ShortCode> shortCodes = GetShortCodes(e.Body, regex, true);

	

			if (shortCodes.Count == 0)

				return;

							

			ProcessMediaTags(e, shortCodes);

			

			// this won't happen on feeds

			if (context.CurrentHandler is Page) {

				Page page = (Page)context.CurrentHandler;

				AddHeader(page);

                AddFooter(page);

			}

		}

	}



    private static void AddHeader(Page page)

    {

		string path = Utils.ApplicationRelativeWebRoot + "Scripts/mediaelement/";

		

		AddJavaScript(path + "mediaelement.min.js", page);

        AddJavaScript(path + "mediaelementplayer.min.js", page);

        AddStylesheet(path + "mediaelementplayer.min.css", page);

    }



    private static void AddJavaScript(string src, Page page)

    {

        HtmlGenericControl script = new HtmlGenericControl("script");

        script.Attributes["type"] = "text/javascript";

        script.Attributes["src"] = src;

        page.Header.Controls.Add(script);

    }



    private static void AddStylesheet(string href, Page page)

    {

        HtmlLink css = new HtmlLink();

        css.Attributes["type"] = "text/css";

        css.Attributes["rel"] = "stylesheet";

        css.Attributes["href"] = href;

        page.Header.Controls.Add(css);

    }



    private static void AddFooter(Page page)

    {



		int width = 0;

		int height = 0;



        if (!Int32.TryParse(Settings.GetSingleValue("width"), out width))

			width = _widthDefault;

        if (!Int32.TryParse(Settings.GetSingleValue("height"), out height))

			height = _heightDefault;      



		string startupScript = @"

<script type=""text/javascript"">

jQuery(document).ready(function($) {

	$('audio.mep, video.mep').mediaelementplayer({defaultVideoWidth:" + width.ToString() + ", defaultVideoHeight:" + height.ToString() + @"});

});

</script>	

";

        page.ClientScript.RegisterStartupScript(page.GetType(), _extensionName, startupScript, false);

	}





    private static void ProcessMediaTags(ServingEventArgs e, List<ShortCode> shortCodes)

    {

	

		// path to media

        string folder = Settings.GetSingleValue("folder");			

		string path = Utils.RelativeWebRoot + folder.TrimEnd(new char[] {'/'}) + "/";

		

		// override for feed

		if (e.Location == ServingLocation.Feed) {

			path = Utils.AbsoluteWebRoot + folder.TrimEnd(new char[] { '/' }) + "/";			

		}

					

		// do replacement for media

		foreach (ShortCode sc in shortCodes)

		{

			string tagName = sc.TagName;

			string src = sc.GetAttributeValue("src", "");

			string w = sc.GetAttributeValue("width", "");

			string h = sc.GetAttributeValue("height", "");



			string mp4 = sc.GetAttributeValue("mp4", "");

			string mp3 = sc.GetAttributeValue("mp3", "");

			string webm = sc.GetAttributeValue("webm", "");

			string ogg = sc.GetAttributeValue("ogg", "");

			

			string poster = sc.GetAttributeValue("poster", "");

			string autoplay = sc.GetAttributeValue("autoplay", "");

			string preload = sc.GetAttributeValue("preload", "");



			string code =

				"<" + tagName + " class=\"mep\" controls=\"controls\"" + ((src != "") ? " src=\"" + ((src.IndexOf("http") == 0) ? "" : path) + src + "\"" : "") + ((poster != "") ? " poster=\"" + ((poster.IndexOf("http") == 0) ? "" : path) + poster + "\"" : "") + ((w != "") ? " width=\"" + w + "\"" : "") + ((h != "") ? " height=\"" + h + "\"" : "") + ((autoplay != "") ? " autoplay=\"autoplay\"" : "") + ((preload != "") ? " preload=\"" + preload + "\"" : "") + ">" +

					((mp4 != "") ? "<source src=\"" + ((mp4.IndexOf("http") == 0) ? "" : path) + mp4 + "\" type=\"video/mp4\" />" : "") +

					((mp3 != "") ? "<source src=\"" +((mp3.IndexOf("http") == 0) ? "" : path) + mp3 + "\" type=\"audio/mp3\" />" : "") +

					((webm != "") ? "<source src=\"" + ((webm.IndexOf("http") == 0) ? "" : path) + webm + "\" type=\"video/webm\" />" : "") +

					((ogg != "") ? "<source src=\"" + ((ogg.IndexOf("http") == 0) ? "" : path) + ogg + "\" type=\"video/ogg\" />" : "") + 

				

				"</" + tagName + ">";		

				

			e.Body = e.Body.Replace(sc.Text, code);

			

		}	

	}		

	

	public static List<ShortCode> GetShortCodes(string input)

    {

		return GetShortCodes(input, true);

	}

    public static List<ShortCode> GetShortCodes(string input, bool removeParagraphs)

    {

		return GetShortCodes(input, @"\w+", removeParagraphs);

	}

    public static List<ShortCode> GetShortCodes(string input, string regexMatchString, bool removeParagraphs)

    {

		List<ShortCode> shortCodes = new List<ShortCode>();



		// get the main tag [tag attr="value"]

		string find = @"\[(?<tag>" + regexMatchString + @")(?<attrs>[^\]]+)\]";

		if (removeParagraphs) {

			find = @"(<p>[\s\n]?)+" + find + @"([\s\n]?</p>)+";

		}

				

		MatchCollection matches = Regex.Matches(input, find);

		

		foreach (Match match in matches) {

			

			string tagName = match.Groups["tag"].Value;

			string attributes = match.Groups["attrs"].Value;



			ShortCode sc = new ShortCode(tagName, match.Value);



			// parse the attributes

			// attr="value"

			MatchCollection attrMatches = Regex.Matches(attributes, @"(?<attr>\w+)=""(?<val>[^""]+)""");			

			

			foreach (Match attrMatch in attrMatches) {

				sc.Attributes.Add(attrMatch.Groups["attr"].Value, attrMatch.Groups["val"].Value);

			}



			shortCodes.Add(sc);

		}

		



		return shortCodes;

	}



    public class ShortCode

    {



		public ShortCode(): this("","") {

		}

		

		public ShortCode(string tagName, string text) {

			_tagName = tagName;

			_text = text;

			_attributes = new Dictionary<string, string>();

		}

		

		private string _tagName;

		private string _text;

		private Dictionary<string, string> _attributes;



		public string TagName { get { return _tagName; } set { _tagName = value; } }

		public string Text { get { return _text; } set { _text = value; } }

		public Dictionary<string, string> Attributes { get { return _attributes; } set { _attributes = value; } }



		public string GetAttributeValue(string attributeName, string defaultValue) {

			if (Attributes.ContainsKey(attributeName))

				return Attributes[attributeName];

			else

				return defaultValue;

		}

	}

	

	

	

}