Asp.Net MVC Manager for javascript include and Css files

I was trying to figure a way to automatically include javascript from html helpers and from view without having to check if it wasn't already in the master so i came up with a simple manager. It is greatly inspired by Frugal Coder Blog and Chris Pietschmann. I build an abstarct manager to perform the operation required by the javascript and css manager.
so here it is :

using System.Collections.Generic;
using System.Text;
using System.Web.Mvc;

namespace MvcExtensions
{
    public abstract class MvcManager
    {
        protected HtmlHelper _htmlHelper;
        protected Dictionary<string, TagBuilder> _include = new Dictionary<string, TagBuilder>();

        public MvcManager(HtmlHelper htmlHelper)
        {
            this._htmlHelper = htmlHelper;
        }

        public virtual MvcManager Include(string path)
        {
            if (!this._include.ContainsKey(path))
            {
                this._include.Add(path, this.BuildTag(UrlHelper.GenerateContentUrl(path, this._htmlHelper.ViewContext.HttpContext)));
            }
            return this;
        }

        public virtual MvcHtmlString Render()
        {
            StringBuilder sb = new StringBuilder();
            foreach (var item in this._include.Values)
            {
                sb.AppendLine(item.ToString());
            }
            return MvcHtmlString.Create(sb.ToString());
        }

        protected abstract TagBuilder BuildTag(string src);
    }
}

And now for the javascript manager:

using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.Mvc;

namespace MvcExtensions
{
    public class MvcClientScriptManager : MvcManager
    {
        private List<string> _readyLine = new List<string>();

        public MvcClientScriptManager(HtmlHelper htmlHelper) : base(htmlHelper) { }

        public new MvcClientScriptManager Include(string path)
        {
            return (MvcClientScriptManager)((MvcManager)this).Include(path);
        }
        public MvcClientScriptManager Include(string path, string debugPath)
        {
            string file = this._htmlHelper.ViewContext.HttpContext.IsDebuggingEnabled ? debugPath : path;
            return this.Include(file);
        }

        public MvcClientScriptManager AddToReady(string code)
        {
            this._readyLine.Add(code);
            return this;
        }

        protected override TagBuilder BuildTag(string src)
        {
            TagBuilder scriptTag = new TagBuilder("script");
            scriptTag.MergeAttribute("type", "text/javascript");
            scriptTag.MergeAttribute("src", src);
            return scriptTag;
        }

        public override MvcHtmlString Render()
        {
            if (this._readyLine.Any())
            {        
                StringBuilder sb = new StringBuilder(base.Render().ToString());
                sb.AppendLine("<script type=\"text/javascript\">");
                sb.AppendLine("$(function() {");
                foreach (var item in this._readyLine)
                {
                    sb.AppendLine("\t" + item);
                }
                sb.AppendLine("});");
                sb.AppendLine("</script>");
                return MvcHtmlString.Create(sb.ToString());
            }
            return base.Render();
        }
    }
}

The CssManager :

using System.Web.Mvc;

namespace MvcExtensions
{
    public class MvcCssManager : MvcManager
    {
        public MvcCssManager(HtmlHelper htmlHelper) : base(htmlHelper) { }

        public new MvcCssManager Include(string path)
        {
            return (MvcCssManager)base.Include(path);
        }

        protected override TagBuilder BuildTag(string src)
        {
            TagBuilder linkTag = new TagBuilder("link");
            linkTag.MergeAttribute("type", "text/css");
            linkTag.MergeAttribute("rel", "stylesheet");
            linkTag.MergeAttribute("href", UrlHelper.GenerateContentUrl(src, this._htmlHelper.ViewContext.HttpContext));
            return linkTag;
        }
    }
}

my master page now looks like this:

<%@ Master Language="C#" Inherits="System.Web.Mvc.ViewMasterPage" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title><asp:ContentPlaceHolder ID="TitleContent" runat="server" /></title>
    <% Html.MvcCssManager().Include("~/Content/Css/Site.css"); %>
    <asp:ContentPlaceHolder ID="HeadContent" runat="server" />

    <%= Html.MvcCssManager().Render()%>
</head>

<body>
    <div class="page">

        <div id="header">
            <div id="title">
                <h1>My MVC Application</h1>
            </div>
      
            <div id="logindisplay">
                <% Html.RenderPartial("LogOnUserControl"); %>
            </div>
    
            <div id="menucontainer">
    
                <ul id="menu">      
                    <li><%= Html.ActionLink("Home", "Index", "Home")%></li>
                    <li><%= Html.ActionLink("About", "About", "Home")%></li>
                    <li><%= Html.ActionLink("Users", "List", "UserManagement")%></li>
                </ul>
    
            </div>
        </div>

        <div id="main">
            <asp:ContentPlaceHolder ID="MainContent" runat="server" />

            <div id="footer">
            </div>
        </div>
    </div>

<%= Html.MvcClientScriptManager().Render() %>

</body>
</html>

And finally a sample view in which I use it:

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<MyTestMVC2App.Areas.UserManagement.Models.User>" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    Edit
</asp:Content>

<asp:Content ID="Content3" ContentPlaceHolderID="HeadContent" runat="server">
<%
    Html.MvcClientScriptManager()
       .Include("~/Scripts/MicrosoftAjax.js", "~/Scripts/MicrosoftAjax.debug.js")
       .Include("~/Scripts/MicrosoftMvcValidation.js", "~/Scripts/MicrosoftMvcValidation.debug.js");
    Html.MvcCssManager().Include("~/Content/Css/Jquery.UI/base/ui.all.css");
%>
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

    <h2>Edit</h2>

    <% Html.EnableClientValidation(); %>

    <% using (Html.BeginForm()) {%>

        <fieldset>
            <legend>Fields</legend>
        
            <%= Html.EditorForModel() %>
        
            <p>
                <input type="submit" value="Save" />
            </p>
        </fieldset>

    <% } %>

    <div>
        <%=Html.ActionLink("Back to List", "List") %>
    </div>

</asp:Content>

So now I'm only referencing script and css hosted on my site but thats for another post...

Feel free to leave comment, I would love to have some feed-back on this.