What is AJAX

Ajax (asynchronous JavaScript and XML), or AJAX, is a group of interrelated web development techniques used for creating interactive web applications.

It is about responsiveness

A primary characteristic is the increased responsiveness of web pages achieved by exchanging small amounts of data with the server "behind the scenes" so that entire web pages do not have to be reloaded each time there is a need to fetch data from the server.

Increasing Interactivity

This is intended to increase the web page's interactivity, speed, functionality and usability.

It is about doing long running tasks in the background

Ajax is asynchronous, in that extra data is requested from the server and loaded in the background without interfering with the display and behavior of the existing page.

What can you learn from the videos

• How to setup Vista and Visual Studio 2008

• Understanding LINQ

• How to create LINQ queries

• How to access relational data with LINQ

• How to access XML data with LINQ

• How to join XML data and relational data

• How to add a console project to test LINQ

• How to debug LINQ

• How to work with databases and the Server Explorer

• How to work with the LINQ DataContext object

• Understanding the "var" keyword and implicitly typed variables

• Looping through collections that result from LINQ queries

• How to work with the LINQ Designer in Visual Studio

• How to add tables and stored procedures to the LINQ Designer

• How to work with the debugger

• How to set breakpoints

• How to fix compiler errors

• How set references and use the "using" statement

• How to step through code using the debugger

• How to work with "Extension Methods" and Lambda Expressions and Anonymous Types

• How to calculate averages based on relational data

WCF Makes it all possible

Windows Communication Foundation (WCF) is the Microsoft unified programming model for building service-oriented applications.

JSON or XML Data Format

It supports ASP.NET AJAX and the JavaScript Object Notation (JSON) data format. XML format is also supported.

JavaScript Implementation

The model enables WCF services to expose functionality to Web pages that run ECMAScript (JavaScript) code and that can therefore access these services by using HTTP requests.

Adding endpoints to support AJAX through WCF

If you have already created WCF services, you can add endpoints to enable script in AJAX-enabled Web pages to access those services.

Automatic Proxy Class Generated

The .NET Framework automatically creates JavaScript proxy classes for the WCF services at page-load time and downloads the proxy class script to the browser.