Combining resources

It is recommended that you download all your scripts/styles in a single request to the server, instead of getting files one by one, thus blocking the browser.

So, instead of:

   <script type="text/javascript" src="../Scripts/romama.js"></script>

   <script type="text/javascript" src="../Scripts/notes.js"></script>

I really want to have something like this:

   <script type="text/javascript" src="../Scripts/combined.js"></script>


Even if there are ready-to-use solution available, like Yahoo! combo handler, this never stopped me before from implementing my own custom solution.

What I want for myself is to be able to put one single script tag in a master page and have all my scripts downloaded as a single file.

    <script type="text/javascript" src="CombineResources.axd?type=script"></script>

I am going to achieve this with the custom HttpHandler, which will know which resources are needed for any particular page. Here is implementation:

public class CombineResources : IHttpHandler

{

       #region Static Members

       private static Dictionary<string, List<string>> ScriptMap = new Dictionary<string, List<string>>()

       {

              {"/Notes/CategoryEditor.aspx", new List<string>() {"/Scripts/romama.js", "/Scripts/categoryEditor.js"}}

       };

       #endregion

       #region IHttpHandler Members

       public bool IsReusable

       {

              get { return true; }

       }

       public void ProcessRequest(HttpContext context)

       {

              string resourceType = context.Request.QueryString["type"] as String;

              if (String.IsNullOrWhiteSpace(resourceType))

              {

                     return;

              }

              string localPath = context.Request.UrlReferrer.LocalPath;

              string combined = context.Cache[localPath + ":" + resourceType] as String;

              if (combined != null)

              {

                     context.Response.Write(combined);

                     return;

              }

              List<string> resources = new List<string>();

              if (resourceType == "script")

              {

                     if (ScriptMap.ContainsKey(localPath))

                     {

                           resources = ScriptMap[localPath];

                     }

              }

              else if (resourceType == "style")

              {

                     // TODO:

              }

              else

              {

                     throw new InvalidOperationException(String.Format("unrecognized resource type: {0}", resourceType));

              }

              StringBuilder sb = new StringBuilder();

              foreach(var resource in resources)

              {

                     sb.AppendLine(File.ReadAllText(context.Server.MapPath("\\") + resource));

              }

              sb.AppendLine(@"// Generated: " + DateTime.Now.ToLocalTime());

              context.Response.Write(sb.ToString());

              context.Cache.Insert(localPath + ":" + resourceType, sb.ToString(), null, DateTime.UtcNow.AddMinutes(1), Cache.NoSlidingExpiration);

       }

       #endregion

}

The thing I need to look into is whether the scripts going to be cached in a browser.