Cross Browser XHR

This works on all popular browsers ...

function sendRequest(url,callback,postData) {

var req = createXMLHTTPObject();

if (!req) return;

var method = (postData) ? "POST" : "GET";

req.open(method,url,true);

req.setRequestHeader('User-Agent','XMLHTTP/1.0');

if (postData)

req.setRequestHeader('Content-type','application/x-www-form-urlencoded');

req.onreadystatechange = function () {

if (req.readyState != 4) return;

if (req.status != 200 && req.status != 304) {

return;

}

callback(req);

}

if (req.readyState == 4) return;

req.send(postData);

}

var XMLHttpFactories = [

function () {return new XMLHttpRequest()},

function () {return new ActiveXObject("Msxml2.XMLHTTP")},

function () {return new ActiveXObject("Msxml3.XMLHTTP")},

function () {return new ActiveXObject("Microsoft.XMLHTTP")}

];

function createXMLHTTPObject() {

var xmlhttp = false;

for (var i=0;i

try {

xmlhttp = XMLHttpFactories[i]();

}

catch (e) {

continue;

}

break;

}

return xmlhttp;

}

call with ....

sendRequest('a-page.aspx',myCallback,"");

Data Layer Without Linq

A good n-tiered approach is to create a [ProjectName].Data class library.

Create a base class.

public class SqlDataCaller

{

private static SqlConnection getConnection()

{

return new SqlConnection(

ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString);

}

protected static DataSet ExecuteSPDataSet(String spName, SqlParameter[] parameters)

{

DataSet ds = new DataSet();

using (SqlConnection connection = getConnection())

{

try

{

connection.Open();

}

catch (SqlException ex)

{

throw ex;

}

SqlDataAdapter da = new SqlDataAdapter(spName, connection);

da.SelectCommand.CommandType = CommandType.StoredProcedure;

if (parameters != null)

da.SelectCommand.Parameters.AddRange(parameters);

try

{

da.Fill(ds);

}

catch (SqlException ex)

{

throw ex;

}

connection.Close();

}

return ds;

}

}

Then in their own namespaces, create classes to pass a DataTable to the business objects.

namespace [Project Name].Data.People

{

using System;

using System.Data;

using System.Data.SqlClient;

using System.Collections.Generic;

using System.Text;

using [Project Name].Data.Base;

///

/// Class responsible for all data access regarding people

///

public class PeopleDAC : SqlDataCaller

{

public const String ColName_PersonId = "PersonId";

public const String ColName_Name = "Name";

public const String ColName_Region = "RegionName";

public const String ColName_DateTime = "TimeDateStamp";

public static DataTable GetPerson(Int32 personId)

{

String spName = "example_GetPerson";

SqlParameter[] parameters = new SqlParameter[1];

parameters[0] = new SqlParameter("@PersonId", SqlDbType.Int, 4);

parameters[0].Value = count;

DataSet ds = ExecuteSPDataSet(spName, parameters);

return ds.Tables[0];

}

}

}