AJAX Dirty-Panel

using System;
using System.Web.UI;
using System.Collections.Generic;
using System.Text;
using ASP = System.Web.UI.WebControls;
using Anthem;
namespace DirtyPanel
{
    public class DirtyPanel : Anthem.Panel
    {
      
        #region Private Members
        private string _onLeaveMessage = "";

        #endregion

        #region Public Properties
        public string OnLeaveMessage
        {
            get { return _onLeaveMessage; }
            set { _onLeaveMessage = value; }
        }
        #endregion

        #region Control State Management

        protected override object SaveControlState()
        {
            object[] state = new object[2];
            state[0] = base.SaveControlState();
            state[1] = this._onLeaveMessage;            
            return state;
        }

        protected override void LoadControlState(object savedState)
        {
            object[] state = (object[])savedState;
            base.LoadControlState(state[0]);
            this._onLeaveMessage = state[1].ToString();
        }
        #endregion

        #region Scripts
        private string GetCurrentValuesScript()
        {
            Dictionary<string, string> controls = new Dictionary<string, string>();            
            RegisterControl(this, controls);

            StringBuilder script = new StringBuilder();
            script.Append("var controls = new Array();");
            script.Append("var values = new Array();");

            int i = 0;
            foreach(KeyValuePair<string, string> control in controls)
            {
                script.Append(string.Format("controls[{0}] = '{1}';", i, control.Key));
                script.Append(string.Format("values[{0}] = {1};", i, control.Value));
                i++;
            }
            return string.Format("<script language=\"javascript\">{0}</script>", script.ToString());
        }

        private void RegisterControl(Control control, Dictionary<string, string> controls)
        {
            if (control.HasControls())
            {
                foreach (Control c in control.Controls)
                    RegisterControl(c, controls);
            }

            if (control is ASP.TextBox)
                controls.Add(control.ClientID, string.Format("'{0}'", ((ASP.TextBox)control).Text));
            else if(control is ASP.DropDownList)
                controls.Add(control.ClientID, ((ASP.DropDownList)control).SelectedIndex.ToString());
            else if (control is ASP.CheckBox)
                controls.Add(control.ClientID, ((ASP.CheckBox)control).Checked.ToString().ToLower());
            else if (control is ASP.RadioButton)
                controls.Add(control.ClientID, ((ASP.RadioButton)control).Checked.ToString().ToLower());
        }

        private string GetDefaultScript()
        {
            return @"<script language='javascript'>
           window.onbeforeunload = function (oEvent) 
           {
                if(IsDirty() == true)
                {
                    if(!oEvent) oEvent = window.event;
                    oEvent.returnValue = '" + this._onLeaveMessage + @"';
                }    
           }
           
           function IsDirty()
           {
                var i=0;
                for (i=0; i< controls.length; i++)
                {                    
                    var control = document.getElementById(controls[i]);
                    if(control.type == 'text' || control.type == 'textarea')
                    {
                        if(control.value != values[i])
                            return true;
                    }
                    else if(control.type == 'select-one')
                    {
                        if(control.selectedIndex != values[i])
                            return true;
                    }
                    else if(control.type == 'checkbox' || control.type == 'radio')
                    {
                        if(control.checked != values[i])
                            return true;
                    }
                }           
                return false;
           }
            </script>";
        }
        #endregion

        protected override void Render(HtmlTextWriter writer)
        {
            writer.Write(GetDefaultScript());
            writer.Write(GetCurrentValuesScript());
            base.Render(writer);
        }

        public void Reset()
        {
            this.UpdateAfterCallBack = true;
            Anthem.Manager.IncludePageScripts = true;
            
        }
    }
}