CategoryList.cs :  » Bloggers » BlogEngine.NET » Controls » C# / CSharp Open Source

#region Using

using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.IO;
using System.Collections.Generic;
using BlogEngine.Core;

#endregion

namespace Controls{
  /// <summary>
  /// Builds a category list.
  /// </summary>
  public class CategoryList : Control
  {

    static CategoryList()
    {
      Post.Saved += delegate { _Html = null; };
      Category.Saved += delegate { _Html = null; };
    }

    #region Properties

    private static bool _ShowRssIcon = true;
    /// <summary>
    /// Gets or sets whether or not to show feed icons next to the category links.
    /// </summary>
    public bool ShowRssIcon
    {
      get { return _ShowRssIcon; }
      set
      {
        if (_ShowRssIcon != value)
        {
          _ShowRssIcon = value;
          _Html = null;
        }
      }
    }

    private bool _ShowPostCount;

    public bool ShowPostCount
    {
      get { return _ShowPostCount; }
      set
      {
        if (_ShowPostCount!= value)
        {
          _ShowPostCount = value;
          _Html = null;
        }
      }
    }


    private static object _SyncRoot = new object();
    private static string _Html;
    private string Html
    {
      get
      {
        if (_Html == null)
        {
          lock (_SyncRoot)
          {
            if (_Html == null)
            {
              HtmlGenericControl ul = BindCategories();
              System.IO.StringWriter sw = new System.IO.StringWriter();
              ul.RenderControl(new HtmlTextWriter(sw));
              _Html = sw.ToString();
            }
          }
        }

        return _Html;
      }
    }

    #endregion

    private HtmlGenericControl BindCategories()
    {
      SortedDictionary<string, Guid> dic = SortCategories();

      if (dic.Keys.Count == 0)
      {
        HtmlGenericControl none = new HtmlGenericControl("p");
        none.InnerText = "None";
        return none;
      }

      HtmlGenericControl ul = new HtmlGenericControl("ul");
      ul.ID = "categorylist";

      foreach (Guid id in dic.Values)
      {

                // Find full category
          Category cat = Category.GetCategory(id);
          string key = cat.CompleteTitle();

        HtmlGenericControl li = new HtmlGenericControl("li");

        if (ShowRssIcon)
        {
          HtmlImage img = new HtmlImage();
          img.Src = Utils.RelativeWebRoot + "pics/rssButton.gif";
          img.Alt = BlogSettings.Instance.SyndicationFormat.ToUpperInvariant() + " feed for " + key;
          img.Attributes["class"] = "rssButton";

          HtmlAnchor feedAnchor = new HtmlAnchor();
                    feedAnchor.HRef = cat.FeedRelativeLink;
          feedAnchor.Attributes["rel"] = "nofollow";
          feedAnchor.Controls.Add(img);

          li.Controls.Add(feedAnchor);
        }

        int posts = Post.GetPostsByCategory(dic[key]).FindAll(delegate(Post p)
        {
          return p.IsVisible;
        }).Count;

        string postCount = " (" + posts + ")";
        if (!ShowPostCount)
          postCount = null;

        HtmlAnchor anc = new HtmlAnchor();
                anc.HRef = cat.RelativeLink;
        anc.InnerHtml = HttpUtility.HtmlEncode(key) + postCount;
        anc.Title = "Category: " + key;

        li.Controls.Add(anc);
        ul.Controls.Add(li);
      }

      return ul;
    }

    private SortedDictionary<string, Guid> SortCategories()
    {
      SortedDictionary<string, Guid> dic = new SortedDictionary<string, Guid>();
      foreach (Category cat in Category.Categories)
      {
        if (HasPosts(cat))
          dic.Add(cat.CompleteTitle(), cat.Id);
      }

      return dic;
    }

    private bool HasPosts(Category cat)
    {
      foreach (Post post in Post.Posts)
      {
        if (post.IsVisible)
        {
          foreach (Category category in post.Categories)
          {
            if (category == cat)
              return true;
          }
        }

      }
      return false;
    }

    /// <summary>
    /// Renders the control.
    /// </summary>
    public override void RenderControl(HtmlTextWriter writer)
    {
      writer.Write(Html);
      writer.Write(Environment.NewLine);
    }
  }
}