using BusinessObjectAndData;
using System;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Web;
using System.Web.Services;
using System.Xml;

public class WebDataService : System.Web.Services.WebService
{
    public WebDataService()
    {
        InitializeComponent();
    }

    #region Component Designer generated code

    [WebMethod]
    public DataSet ExecuteQuery(
        string commandXml, string resultName)
    {
        SqlCommand  cmd = this.GetCommandFromXml(commandXml);
        IDataService oService =
            DataServiceFactory.GetDataService();
        return oService.ExecuteQuery(cmd,resultName);
    }

    [WebMethod]
    public void ExecuteNonQuery(string commandXml)
    {
        SqlCommand  cmd = this.GetCommandFromXml(commandXml);
        IDataService oService =
            DataServiceFactory.GetDataService();
        oService.ExecuteNonQuery(cmd);
    }

    [WebMethod]
    public object ExecuteScalar(string commandXml)
    {
        SqlCommand  cmd = this.GetCommandFromXml(commandXml);
        IDataService oService = 
            DataServiceFactory.GetDataService();
        return oService.ExecuteScalar(cmd);
    }

    [WebMethod]
    public bool IsValid()
    {
        IDataService oService =
            DataServiceFactory.GetDataService();
        return oService.IsValid();
    }

    private SqlCommand GetCommandFromXml(string commandXml)
    {
        SqlCommand cmd = new SqlCommand();
        XmlDocument xml = new XmlDocument();
        xml.LoadXml(commandXml);

        XmlNode nodeText = xml.SelectSingleNode("command/text");
        cmd.CommandText = nodeText.InnerText;

        XmlNode nodeType = xml.SelectSingleNode("command/type");
        if (nodeType.InnerText == "StoredProcedure")
        {
            cmd.CommandType = CommandType.StoredProcedure;
        }

        XmlNodeList parameters = 
            xml.SelectNodes("command/parameters/parameter");
        foreach(XmlNode nodePara in parameters)
        {
            XmlNode nodeName = nodePara.SelectSingleNode("@name");
            cmd.Parameters.Add(nodeName.InnerText,
                nodePara.InnerText);
        }
        return cmd;
    }
}