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

#region Using

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

#endregion

namespace Controls{
  /// <summary>
  /// Builds a category list.
  /// </summary>
  public class MonthList : Control
  {
    private const double CacheTimeoutInHours = 1;

    static MonthList()
    {
      Post.Saved += Post_Saved;
    }

    static void Post_Saved(object sender, SavedEventArgs e)
    {
      // invalidate cache whenever a post is modified
      lock (_SyncRoot)
      {
        HttpRuntime.Cache.Remove(CacheKey);
      }

    }

    #region Private fields

    private readonly static object _SyncRoot = new object();
    private const string CacheKey = "BE_MonthListCacheKey";
    #endregion

    private static SortedDictionary<DateTime, int> GetPostsPerMonth()
    {
      lock (_SyncRoot)
      {
        SortedDictionary<DateTime, int> months = HttpRuntime.Cache[CacheKey] as SortedDictionary<DateTime, int>;
        if (months == null)
        {
          months = new SortedDictionary<DateTime, int>();
          // let dictionary expire after 1 hour
          HttpRuntime.Cache.Insert(CacheKey, months, null, DateTime.Now.AddHours(CacheTimeoutInHours), Cache.NoSlidingExpiration);

          foreach (Post post in Post.Posts)
          {
            if (post.IsVisibleToPublic)
            {
              DateTime month = new DateTime(post.DateCreated.Year, post.DateCreated.Month, 1);
              int count;
              // if the date is not in the dictionary, count will be set to 0
              months.TryGetValue(month, out count);
              ++count;
              months[month] = count;
            }
          }
        }
        return months;
      }
    }

    private string RenderMonths()
    {
      SortedDictionary<DateTime, int> months = GetPostsPerMonth();
      if (months.Keys.Count == 0)
        return "<p>" + Resources.labels.none + "</p>";

      HtmlGenericControl ul = new HtmlGenericControl("ul");
      ul.Attributes.Add("id", "monthList");
      HtmlGenericControl year = null;
      HtmlGenericControl list = null;
      int current = 0;

      foreach (DateTime date in months.Keys)
      {
        if (current == 0)
          current = date.Year;

        if (date.Year > current || ul.Controls.Count == 0)
        {
          list = new HtmlGenericControl("ul");
          list.ID = "year" + date.Year.ToString();

          year = new HtmlGenericControl("li");
          year.Attributes.Add("class", "year");
          year.Attributes.Add("onclick", "BlogEngine.toggleMonth('year" + date.Year + "')");
          year.InnerHtml = date.Year.ToString();
          year.Controls.Add(list);

          if (date.Year == DateTime.Now.Year)
            list.Attributes.Add("class", "open");

          ul.Controls.AddAt(0, year);
        }

        HtmlGenericControl li = new HtmlGenericControl("li");

        HtmlAnchor anc = new HtmlAnchor();
        anc.HRef = Utils.RelativeWebRoot + date.Year + "/" + date.ToString("MM") + "/default" + BlogSettings.Instance.FileExtension;
        anc.InnerHtml = DateTime.Parse(date.Year + "-" + date.Month + "-01").ToString("MMMM") + " (" + months[date] + ")";

        li.Controls.Add(anc);
        list.Controls.AddAt(0, li);
        current = date.Year;
      }

      System.IO.StringWriter sw = new System.IO.StringWriter();
      ul.RenderControl(new HtmlTextWriter(sw));
      return sw.ToString();
    }

    private SortedDictionary<string, Guid> SortGategories(Dictionary<Guid, string> categories)
    {
      SortedDictionary<string, Guid> dic = new SortedDictionary<string, Guid>();
      foreach (Guid key in categories.Keys)
      {
        dic.Add(categories[key], key);
      }

      return dic;
    }

    /// <summary>
    /// Renders the control.
    /// </summary>
    public override void RenderControl(HtmlTextWriter writer)
    {
      if (Post.Posts.Count > 0)
      {
        string html = RenderMonths();
        writer.Write(html);
        writer.Write(Environment.NewLine);
      }
    }
  }
}