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Rating Demystified: Ajax Way, Amazon Way*

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4.73/5 (77 votes)
16 Aug 2008CPOL3 min read 178K   1.2K   136  
Ever wondered, how the amazon rating system works with multiple items in the same page, here is a simple article to describe the basic bare bones needed to create an asynchronous rating module using ASP.NET , SQL Server and ..... AJAX
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.IO;
using System.Text;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;  
using System.Configuration; 
using System.Reflection;
using System.Xml; 


namespace Rating
{
	/// <summary>
	/// Summary description for PhotoAll.
	/// </summary>
	public class PhotoAll : System.Web.UI.Page
	{
		protected System.Web.UI.WebControls.Label lblTotal;
		protected System.Web.UI.WebControls.Label lblScore;
		protected System.Web.UI.WebControls.Label lblVotes;
		protected System.Web.UI.WebControls.Label lblView;
		protected System.Web.UI.WebControls.Label lblAjax;
		protected System.Web.UI.WebControls.Label lblRating;
		protected System.Web.UI.WebControls.Label lblDescription;
		protected System.Web.UI.WebControls.Label lblAddedby;
		protected System.Web.UI.WebControls.Image imgPhoto;
		protected System.Web.UI.WebControls.Literal ltlAll;
		protected System.Web.UI.WebControls.Label lblTitle;

		private void Page_Load(object sender, System.EventArgs e)
		{
			if (!IsPostBack)
			{
			int RatedBy = 0;
			int Score = 0;
			string Title ="";
			
			// Put user code to initialize the page here
			string query = "SELECT * FROM " + ConfigurationSettings.AppSettings["MyPhotos"];  
			
			clsDataAccess mydataAccess  = new clsDataAccess();
			mydataAccess.openConnection();
			SqlDataReader mydr = mydataAccess.getData(query);

				if (mydr.HasRows)
				{
					while( mydr.Read())
					{
						if (mydr.GetValue(Convert.ToInt32(ConfigurationSettings.AppSettings["ScoreField"]))!=null)
							Score = Convert.ToInt32(mydr.GetValue(Convert.ToInt32(ConfigurationSettings.AppSettings["ScoreField"])).ToString());

						if (mydr.GetValue(Convert.ToInt32(ConfigurationSettings.AppSettings["RatedByField"]))!=null)
							RatedBy= Convert.ToInt32(mydr.GetValue(Convert.ToInt32(ConfigurationSettings.AppSettings["RatedByField"])).ToString());
			
						if (mydr.GetValue(Convert.ToInt32(ConfigurationSettings.AppSettings["TitleField"]))!=null) 
							Title  = mydr.GetValue(Convert.ToInt32(ConfigurationSettings.AppSettings["TitleField"])).ToString() ;

						int myid = Convert.ToInt32(mydr.GetValue(0));

						double myScore = Convert.ToDouble(Score);
						double myRatedBy = Convert.ToDouble(RatedBy);

						double ORating = 0.0;

						if (myRatedBy>0)
							ORating = myScore/myRatedBy;
			
						string myTotalRatingString = "";

						if ((ORating <1)&&(ORating>0))
							myTotalRatingString = ".5";
						else if (ORating ==1.0)
							myTotalRatingString = "1";
						else if ((ORating >1)&&(ORating<2))
							myTotalRatingString = "1.5";
						else if (ORating ==2.0)
							myTotalRatingString = "2";
						else if ((ORating >2)&&(ORating<3))
							myTotalRatingString = "2.5";
						else if (ORating ==3.0)
							myTotalRatingString = "3";
						else if ((ORating >3)&&(ORating<4))
							myTotalRatingString = "3.5";
						else if (ORating ==4.0)
							myTotalRatingString = "4";
						else if ((ORating >4)&&(ORating<5))
							myTotalRatingString = "4.5";
						else if (ORating ==5.0)
							myTotalRatingString = "5";
						else if (ORating ==0.0)
							myTotalRatingString = "0";

						string lblRatingAjax = "<IMG src='images/stars" + myTotalRatingString + ".gif'>" ;
					
						string DisplayStarsAjax="";
						string DisplayMsgAjax="";
					
						if (Request.Cookies["RatedAjax" + myid] == null) 
						{
							DisplayStarsAjax = "<script language='Javascript'>DisplayStarsAjax(" + myid + ", rating);</script>";
							DisplayMsgAjax = "<script language='Javascript'>DisplayMsgAjax(" + myid + ");</script>";
						}
						else
						{
							HttpCookie cookieAjax = Request.Cookies["RatedAjax" + myid];
							DisplayStarsAjax = "<img src = images/" + cookieAjax.Values[0] + "star.gif>";
							DisplayMsgAjax = "<img src = images/saved.gif>";
						}
						string lblRatingAmz;
						if (Request.Cookies["RatedAmz" + myid] == null) 
						{
							lblRatingAmz = "<iframe src='Rate.aspx?id=" + myid + "' width='310' Height='28' frameborder='0' bgcolor='#F2EFE0'></iframe>";
						}
						else
						{
							HttpCookie cookieAmz = Request.Cookies["RatedAmz" + myid];
						
							StringBuilder sb1 = new StringBuilder();
							string myAmzRated =  sb1.Append( @"<TABLE CELLPADDING=0 CELLSPACING=0><TR><TD>&nbsp;&nbsp;</TD><TD><table width='300' border='0' cellspacing='0' cellpadding='1'>" )
								.Append( @"<tr><td align='left' width='64'  height='26' valign='middle'>" )
								.Append( @"" + lblRatingAjax + "</td>" )
								.Append( @"<td align='left' height='26' width='101'><img src = images/" + cookieAmz.Values[0] + "star.gif></td>" )
								.Append( @"<td align='left' width='66'>" )
								.Append( @"<img src = images/saved.gif></td></tr></table></TD></TR></TABLE>")
								.ToString();
							lblRatingAmz = myAmzRated;
						}
					


					
						StringBuilder sb = new StringBuilder();
						string myString =  sb.Append( @"<TABLE cellSpacing='1' cellPadding='1' width='500' border='1'>" )
							.Append( @"<TR><TD vAlign='middle' Width=30%>&nbsp;<SPAN><FONT face='Arial'>" )
							.Append( "&nbsp;&nbsp;<STRONG>" + Title + "</STRONG><br>&nbsp;&nbsp;<a href='Photo.aspx?id=" + myid + "'>View>></a><br>")
							//.Append( @"&nbsp;&nbsp;<a href='Photo.aspx?id=" + myid + "'><img src ='image.aspx?id=" + myid + "&imgColumn=3'" + " Height='100px' Width='100px' style='BORDER-RIGHT: silver 4px solid; BORDER-TOP: silver 4px solid; BORDER-LEFT: silver 4px solid; BORDER-BOTTOM: silver 4px solid' ></a><BR>")
							//.Append( @"&nbsp;&nbsp;<FONT face='Arial' size='2'>Added By:" + AddedBy + "<BR>")
							.Append( @"</TD><TD vAlign='top'>")
							.Append( @"<STRONG><FONT face='Arial' size='2'>&nbsp;&nbsp;Rate:</FONT></STRONG>&nbsp;&nbsp;<FONT face='Arial' size='2'>Amazon	way - IFrames <BR>" + lblRatingAmz)
							.Append( @"<BR><STRONG><FONT face='Arial' size='2'>&nbsp;&nbsp;Rate:</FONT>&nbsp;</STRONG>&nbsp;<FONT face='Arial' size='2'>AJAX way&nbsp;- no refresh<BR>" )
							.Append( @"<table height='24' cellSpacing='4' cellPadding='4' width='300' bgColor='#f7f5f5' border='0'><tr><td>")
							.Append( @"<table height='24' cellSpacing='0' cellPadding='0' width='300' bgColor='#f7f5f5' border='0'><tr>")
							.Append( @"<td vAlign='middle' align='left' width='64'><DIV id='mytrating" + myid + "'>" + lblRatingAjax )
							.Append( @"</DIV></td>")
							.Append( @"<td align='left' width='101' height='26' valign='middle'>")
							.Append( @"<DIV id='ltlstars" + myid + "'>")
							.Append( @"" + DisplayStarsAjax + "")
							.Append( @"</DIV></td>")
							.Append( @"<td align='left' width='66' valign='middle'>")
							.Append( @"<DIV id='ltlMsg" + myid + "'>")
							.Append( @"" + DisplayMsgAjax + "")
							.Append( @"</DIV>")
							.Append( @"</td></tr></table></td></tr></table>")
							.Append( @"<table border = 0 width=300><tr><td><FONT face='Arial' size='2'><STRONG>Statistics&nbsp;&nbsp;</STRONG></FONT></td>")
							.Append( @"<td>")
							.Append( @"<FONT face='Arial' size='2' color=#006600><b><div id = 'lblVotes" + myid + "'>" + RatedBy.ToString())
							.Append( @"</div></b></font></td><td><FONT face='Arial' size='2'>&nbsp;rating(s)</FONT></td>")
							.Append( @"<td><FONT face='Arial' size='2'>&nbsp;&nbsp;Score:</STRONG>&nbsp;</FONT></td><td>")
							.Append( @"<FONT face='Arial' size='2' color=#006600><b><div id = 'lblScore" + myid + "'>" + Score.ToString())
							.Append( @"</div></b></font></td><td><b>&nbsp;/&nbsp;</b></td><td><FONT face='Arial' size='2' color=#006600><b><div id = 'lblTotal" + myid + "'>" + (RatedBy * 5).ToString())
							.Append( @"</div></b></font></td></tr></table></TD></TR></TABLE>")
							.ToString( ) ;



						ltlAll.Text = ltlAll.Text + myString;
					
					
					}
					mydr.Close();
					mydataAccess.closeConnection(); 

				}
			}
			
		}

		#region Web Form Designer generated code
		override protected void OnInit(EventArgs e)
		{
			//
			// CODEGEN: This call is required by the ASP.NET Web Form Designer.
			//
			InitializeComponent();
			base.OnInit(e);
		}
		
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{    
			this.Load += new System.EventHandler(this.Page_Load);

		}
		#endregion

	}
}

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License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Founder Teamcal AI
United States United States

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