Manage ASP.NET Server Controls, Event Handlers, and Server-Side Validation Using XML and XSLT

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.XPath;
using System.Xml.Xsl;
using System.IO;
using System.Xml;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Init(object sender, EventArgs e)
    {
        ParseControls();
        BindInfo();
    }
    private void ParseControls()
    {
        BindDDL();
        //create argument list
        XsltArgumentList xslArg = new XsltArgumentList();
        xslArg.AddParam("employeeId", "", ddlEmployee.SelectedValue);

        //load the data
        XPathDocument xdoc = new XPathDocument(Server.MapPath("Address.xml"));
        //load Xslt
        XslCompiledTransform transform = new XslCompiledTransform();
        transform.Load(Server.MapPath("DynamicControls.xslt"));
        StringWriter sw = new StringWriter();
        //transform it
        transform.Transform(xdoc, xslArg, sw);
        string result = sw.ToString();

        //remove namespace
        result = result.Replace("xmlns:asp=\"remove\"", "");
        //parse control
        Control ctrl = Page.ParseControl(result);
        phEmployeeAddress.Controls.Add(ctrl);
    }
    private void BindInfo()
    {
        lblMessage.Text = "";
        
        //find dropdown control and update datasource
        try
        {
            DropDownList ddlCountry1 = phEmployeeAddress.FindControl("ddlCountry1") as DropDownList;
            string selectedValue1 = ddlCountry1.Items[0].Value.Trim();
            ddlCountry1.DataSource = GetCountryList();
            ddlCountry1.DataBind();

            DropDownList ddlCountry2 = phEmployeeAddress.FindControl("ddlCountry2") as DropDownList;
            string selectedValue2 = ddlCountry2.Items[0].Value.Trim();
            ddlCountry2.DataSource = GetCountryList();
            ddlCountry2.DataBind();

            //select the selected value
            ddlCountry1.SelectedValue = selectedValue1;
            ddlCountry2.SelectedValue = selectedValue2;
        }
        catch 
        { 
            //ex
            throw;
        }
        //find control to add event handler
        /*===============================================================
        Note: Event handler adding process should be after parsing 
         * the controls since controls will be available after parsing
        =================================================================*/
        Button btnSaveAddress = (Button)phEmployeeAddress.FindControl("btnSaveAddress");
        btnSaveAddress.Click += new EventHandler(btnSaveAddress_Click);
    }
    private void BindDDL()
    {
        if (Context.Request.QueryString["id"] != null)
        {
            ddlEmployee.SelectedValue = Context.Request.QueryString["id"];
        }
    }
    protected void btnLoadData_Click(object sender, EventArgs e)
    {
        string qryString = "?id=" + ddlEmployee.SelectedValue;
        Response.Redirect("Default.aspx" + qryString);
    }
    protected void btnSaveAddress_Click(object sender, EventArgs e)
    {
        XmlDocument doc = new XmlDocument();
        doc.Load(Server.MapPath("Address.xml"));
        XmlNodeList nodeList= doc.SelectNodes("/root/Employee");
        int ind1=1;
        int ind2=1;
        foreach (XmlNode parentNode in nodeList)
        {
            if (parentNode.Attributes.GetNamedItem("Id").Value.Equals(ddlEmployee.SelectedValue))
            {
                XmlNode sectionItem = parentNode.SelectSingleNode("Address");
                foreach (XmlNode node in sectionItem.ChildNodes)
                {
                    ind2 = 1;
                    foreach (XmlNode subNode in node.ChildNodes)
                    {
                        string ctrlId = subNode.Attributes.GetNamedItem("Caption").Value + "_" + ind1 + ind2;
                        ctrlId = ctrlId.Replace(' ', '_');
                        string ctrlType = subNode.Attributes.GetNamedItem("Type").Value;
                        if (ctrlType.Equals("CountryDDL"))
                        {
                            object ctrl = phEmployeeAddress.FindControl("ddlCountry"+ind1);
                            DropDownList ddlCountry = ctrl as DropDownList;
                            subNode.InnerText = ddlCountry.SelectedValue;
                        }
                        else
                        {
                            object ctrl = phEmployeeAddress.FindControl(ctrlId);
                            TextBox txtbox = ctrl as TextBox;
                            subNode.InnerText = txtbox.Text;
                        }
                        ind2 += 1;
                    }
                    ind1 += 1;
                }
            }
        }
        doc.Save(Server.MapPath("Address.xml"));
        lblMessage.Text = "Data Saved Successfully";
    }
    private ArrayList GetCountryList()
    {
        ArrayList al = new ArrayList();
        al.Add(new ListItem("Bangladesh", "BD"));
        al.Add(new ListItem("Japan", "JP"));
        al.Add(new ListItem("United States", "USA"));
        return al;
    }
}