Keyword Matching RSS Reader Control

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Xml;
using System.Text;


/// <summary>
/// RSS Reader Control
/// 
/// litCopy literal control will display control messages, ie: No RSS feed defined
/// 
/// Following properties are customizable:
///     - SourceRss (RSS URL) - can be comma-delimited when using titleKeyword matching
///     - TitleKeywords - match these in titles
///     - TitleLength - number of characters to display in the title before truncating at the last word, and adding '...'
///     - ShowTitles
///     - ShowDescriptions
///     - ShowLinks
///     - Width
///     - Height
///     - RowsToDisplay
///     - LinkTarget
///     - UseTitleBullets
///     
/// ie. in our class where the control has been imported, use:
///     RssReader1.Width = xxx; 
///     RssReader1.Height = xxx;
/// </summary>
public partial class Controls_RssReader : System.Web.UI.UserControl
{

    ArrayList arrSourceRss;
    ArrayList arrTitleKeywords;

    private string _linkTarget;
    /// <summary>
    /// Default is _blank {_blank, _self, _parent, _top}
    /// </summary>
    public string LinkTarget
    {
        get { return _linkTarget; }
        set { _linkTarget = value; }
    }

    private bool _useTitleBullets;
    /// <summary>
    /// Prefix each title with bullets
    /// </summary>
    public bool UseTitleBullets
    {
        get { return _useTitleBullets; }
        set { _useTitleBullets = value; }
    }

    private string _RenderType;
    /// <summary>
    /// {Text, DataGrid} Render the RSS feed as Text or DataGrid
    /// </summary>
    public string RenderType
    {
        get { return _RenderType; }
        set { _RenderType = value.ToLower(); }
    }

    private string _rowDivider;
    /// <summary>
    /// Row divider, ie. '<hr />'
    /// </summary>
    public string RowDivider
    {
        get { return _rowDivider; }
        set { _rowDivider = value; }
    }

    private bool _showLinks;
    /// <summary>
    /// Show links for each RSS item
    /// </summary>
    public bool ShowLinks
    {
        get { return _showLinks; }
        set { _showLinks = value; }
    }


    private bool _showDescriptions;

    /// <summary>
    /// Show descriptions for each RSS Item
    /// </summary>
    public bool ShowDescriptions
    {
        get { return _showDescriptions; }
        set { _showDescriptions = value; }
    }

    private bool _showTitles;

    /// <summary>
    /// Show titles for each RSS Item
    /// </summary>
    public bool ShowTitles
    {
        get { return _showTitles; }
        set { _showTitles = value; }
    }

    private string _sourceRss;

    /// <summary>
    /// Specify the source for the RSS Feed.  Comma-delimited for multiple feeds, when titles require specific keywords
    /// </summary>
    public string SourceRss
    {
        get { return _sourceRss; }
        set { _sourceRss = value; }
    }

    private string _titleKeywords;

    public string TitleKeywords
    {
        get { return _titleKeywords; }
        set { _titleKeywords = value; }
    }

    private int _width;

    /// <summary>
    /// Width of the feed
    /// </summary>
    public int Width
    {
        get { return _width; }
        set { _width = value; }
    }

    private int _rowsToDisplay;
    /// <summary>
    /// Number of rows from the feed to display
    /// </summary>
    public int RowsToDisplay
    {
        get { return _rowsToDisplay; }
        set { _rowsToDisplay = value; }
    }

    private int _titleLength;
    /// <summary>
    /// Number of characters to display before showing "..."
    /// </summary>
    public int TitleLength
    {
        get { return _titleLength; }
        set { _titleLength = value; }
    }


    private void Page_Init(object sender, System.EventArgs e)
    {
        this.EnableViewState = false;
    }

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {

        }

        if (RenderType == String.Empty | RenderType == null)
        {
            RenderType = "Text";
        }

        if (ShowDescriptions)
            _showDescriptions = true;
        if (ShowLinks)
            _showLinks = true;
        if (ShowTitles)
            _showTitles = true;

        if (_width == 0)
        {
            _width = 600;
        }
        dgFeed.Width = _width;          // for datagrid
        PnlTextFeed.Width = _width;     // for text render

        dgFeed.Visible = true;
        //litCopy.Visible = false;
        LoadData();

    }

    protected void LoadData()
    {
        bool addRow = false;
        int rowCount = 0;

        DataTable dtFeed;
        int dtFeedRowCount = 0;
        StringBuilder sb = new StringBuilder();

        string rowTitle = "";

        if (_rowsToDisplay == 0)
        {
            _rowsToDisplay = 5;
        }

        if (!HasValue(_sourceRss))
        {
            sb.Append("<font color=red><b>No RSS source has been specified in your file's code-behind.</b><br>For example:");
            sb.Append("<pre>RssReader1.SourceRss = \"RssReader1.SourceRss = \"http://news.google.com/news?hl=en&ned=us&q=carbon+offset&ie=UTF-8&output=rss,http://news.google.com/news?hl=en&ned=us&q=bio+fuel&ie=UTF-8&output=rss,http://news.google.com/news?hl=en&ned=us&q=eliminate+poverty&ie=UTF-8&output=rss,http://news.google.com/news?hl=en&ned=us&q=Jatropha+trees&ie=UTF-8&output=rss,http://news.google.com/news?hl=en&ned=us&q=reduce+global+warming&ie=UTF-8&output=rss,http://news.google.com/news?hl=en&ned=us&q=tree+planting&ie=UTF-8&output=rss,http://news.google.com/news?hl=en&ned=us&q=carbon+neutral&ie=UTF-8&output=rss,http://news.google.com/news?hl=en&ned=us&q=green+business&ie=UTF-8&output=rss,http://news.google.com/news?hl=en&ned=us&q=Jatropha+plantations&ie=UTF-8&output=rss,http://news.google.com/news?hl=en&ned=us&q=carbon+footprint&ie=UTF-8&output=rss\";<br />");
            sb.Append("RssReader1.TitleKeywords = \"global warming,carbon footprint,global warming solutions,prevent global warming,offset carbon footprint\"");
            sb.Append("RssReader1.RowsToDisplay = 5;<br />");
            sb.Append("RssReader1.Width = 400;<br />");
            sb.Append("RssReader1.ShowLinks = false;<br />");
            sb.Append("RssReader1.ShowTitles = true;<br />");
            sb.Append("RssReader1.ShowDescriptions = false;<br />");
            sb.Append("RssReader1.RowDivider = \"&lt;hr&gt;\";</pre></font>");

            litCopy.Text = sb.ToString();
        }
        if (HasValue(_sourceRss))
        {
            // if TitleKeywords contains values, cycle through the list of RSS feeds to get 
            // titles with those keywords.

            if (HasValue(_titleKeywords))
            {
                arrTitleKeywords = new ArrayList(_titleKeywords.ToLower().Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries));
            }
            else
            {
                arrTitleKeywords = new ArrayList();
            }

            arrSourceRss = new ArrayList(_sourceRss.Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries));

            if (RenderType == "text" && _useTitleBullets)
            {
                sb.Append("<ul>");
            }            

            for (int x = 0; x < arrSourceRss.Count; x++)
            {
                if (rowCount >= _rowsToDisplay)
                {
                    break;
                }

                dtFeed = GetRSSFeed(arrSourceRss[x].ToString()).Copy();
                //Response.Write("hasdata: " + dtFeed.Rows.Count);
                dtFeedRowCount = dtFeed.Rows.Count;
                if (dtFeedRowCount > 0)
                {
                    if (RenderType == "text")
                    {
                        // use bullets - create the unordered list

                        // rows
                        foreach (DataRow row in dtFeed.Rows)
                        {
                            // columns in rows: title, link, item_Id, pubDate, description, channel_Id
                            foreach (DataColumn col in dtFeed.Columns)
                            {
                                //Response.Write("<b>COL: </b>: " + row[col] + ": " + col + "<br>");

                                //
                                // If TitleKeywords has values - optimizing title text 
                                //
                                addRow = false;

                                // check the rows to display
                                if (rowCount <= _rowsToDisplay)
                                {
                                    addRow = true;
                                }
                                else
                                {
                                    break;
                                }

                                rowTitle = row["title"].ToString();


                                if (_titleLength != 0)
                                {
                                    // limit the title to the number of characters - to the last word
                                    // get subset, then find last space, and truncate
                                    try
                                    {
                                        rowTitle = rowTitle.Substring(0, _titleLength);
                                        rowTitle = rowTitle.Substring(0, rowTitle.LastIndexOf(' ')) + " ...";
                                    }
                                    catch (Exception)
                                    {
                                        // do nothing
                                    }
                                }

                                if (arrTitleKeywords.Count > 0)
                                {
                                    foreach (string keywords in arrTitleKeywords)
                                    {
                                        if (rowTitle.ToLower().Contains(keywords.ToLower().Trim()))
                                        {
                                            addRow = true;
                                            break;
                                        }
                                        else
                                        {
                                            addRow = false;
                                        }
                                    }
                                }
                                else
                                {
                                    // since we're not filtering the rows based on keywords, always add them
                                    addRow = true;
                                }

                                if (addRow)
                                {
                                    rowCount ++;
                                    // Bullets
                                    if (_useTitleBullets)
                                    {
                                        sb.Append("<li>");
                                    }

                                    //
                                    // Titles - with/without links
                                    //
                                    if (_showTitles & _showLinks)
                                    {
                                        // link target
                                        if (HasValue(_linkTarget))
                                        {
                                            sb.Append("<a href='" + row["link"] + "' target='" + _linkTarget + "'>");
                                        }
                                        else
                                        {
                                            sb.Append("<a href='" + row["link"] + "' target='_blank'>");
                                        }

                                        sb.Append(rowTitle);
                                        sb.Append("</a>");
                                    }
                                    else if (_showTitles & !_showLinks)
                                    {
                                        sb.Append(rowTitle);
                                    }

                                    // Description
                                    if (_showDescriptions)
                                    {
                                        sb.Append(row["description"]);
                                    }

                                    // Bullets
                                    if (_useTitleBullets)
                                    {
                                        sb.Append("</li>");
                                    }

                                    if (dtFeed.Rows.Count > 1)
                                    {
                                        sb.Append(_rowDivider);
                                    }

                                    break;
                                }   // addRow == true
                            }   // col
                            if (rowCount >= _rowsToDisplay)
                            {
                                break;
                            }
                        }   // row

                    }
                    else if (RenderType == "datagrid")
                    {
                        dgFeed.DataSource = dtFeed;
                        try
                        {
                            dgFeed.DataBind();

                        }
                        catch (HttpException)
                        {
                            // some feeds may not have the description field, if no information is available, only title
                            dgFeed.Visible = false;
                            litCopy.Text = "No recent information has been posted.";
                            litCopy.Visible = true;
                        }
                    }
                }
            }

            // use bullets - create the unordered list
            if (RenderType == "text" && _useTitleBullets)
            {
                sb.Append("</ul>");
            }

            if (RenderType == "text")
            {
                // add the content to the page
                litFeed.Text = sb.ToString();
            }



            // if after iterations, still no data, present default copy
            if (dtFeedRowCount == 0)
            {
                dgFeed.Visible = false;
                litCopy.Text = "No data found.";
                litCopy.Visible = true;
            }
        }
    }

    /// <summary>
    /// Gets the content of an RSS feed, and populates a DataTable 
    /// </summary>
    /// <param name="thisNetworkName"></param>
    /// <returns></returns>
    protected DataTable GetRSSFeed(string RSS_FEED)
    {
        DataSet ds = new DataSet();
        DataTable outputTable = new DataTable();
        DataView dv;

        // if that fails, then use the country name + mobile

        //http://www.flipdog.com/rss/belize/
        //http://www.topix.net/rss/world/canada
        //http://www.infoplease.com/ipa/A0004379.html - world stats
        // if the feed is not found with the entire name, retry with the first word, adding "mobile" to it

        try
        {
            XmlTextReader reader = new XmlTextReader(RSS_FEED);
            ds.ReadXml(reader);         // populate dataset
        }
        catch (Exception)
        {
            // do nothing;
            Response.Write("Data Unavailable");

        }


        if (ds.Tables.Count > 3)
        {
            // populate dv so we can filter out extra <item> rows
            dv = new DataView(ds.Tables[3]);
            //outputTable = dv.Table.Clone();
            outputTable = dv.Table.Copy();


            //try
            //{

            //    // iterate through the dv rows, copy them to the outputTable until max rows is reached
            //    for (int rowCount = 0; rowCount < ; rowCount++)
            //    {
            //        outputTable.ImportRow(dv.Table.Rows[rowCount]);
            //    }

            //    // some feeds may not have the 'description' field if the title indicates no data
            //    //if (!outputTable.Columns.Contains("description"))
            //    //{
            //    //    DataColumn dataColumn = new DataColumn();
            //    //    dataColumn.DataType = Type.GetType("System.String");
            //    //    dataColumn.ColumnName = "description";
            //    //    outputTable.Columns.Add(dataColumn);
            //    //}

            //    return outputTable;
            //}
            //catch (IndexOutOfRangeException orex)
            //{
            //    // do nothing - no more rows to read
            //}

            return outputTable;
        }


        return outputTable;


    }

    /// <summary>
    /// Checks if a QueryString or other object contains a value.
    /// </summary>
    /// <param name="o"></param>
    /// <returns></returns>
    public bool HasValue(object o)
    {
        if (o == null)
        {
            return false;
        }

        if (o == System.DBNull.Value)
        {
            return false;
        }

        if (o is String)
        {
            if (((String)o).Trim() == String.Empty)
            {
                return false;
            }
        }

        return true;
    }

    /// <summary>
    /// Removed unwanted fields from the RSS dg display
    /// Set by, ie. RssReader1.ShowTitles = true;
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void dgFeed_ItemCreated(object sender, DataGridItemEventArgs e)
    {
        try
        {
            if (HasValue(((DataRowView)e.Item.DataItem).Row["title"]))
            {
                if (!_showTitles)
                {
                    ((DataRowView)e.Item.DataItem).Row["title"] = String.Empty;
                }
                if (!_showLinks)
                {
                    ((DataRowView)e.Item.DataItem).Row["link"] = String.Empty;
                }
                if (!_showDescriptions)
                {
                    ((DataRowView)e.Item.DataItem).Row["description"] = String.Empty;
                }

            }
        }
        catch (Exception)
        {
            // do nothing
        }
    }
}