·        Objective

o       Concept behind web services

o       How to use web service and deploy

 XML, SOAP and WSDL

·        XML

o       XML – Extensible Markup Language – provide a format for describing data

o       Similar to HTML – use concept of TAG

o       The different – XML can create own tags – HTML cannot

o       Tags – to define the structure and data types

o       //msdn.microsoft.com/xml

·        SOAP

o       XML based protocol for exchanging structured and type info on the web

o       Web service use SOAP protocol = TCP/IP and HTTP to communicate with clients

o       SOAP msgs sent to/from a web service must be in XML

·        WSDL

•  
  • Web Services Description Language which is an XML grammar that is used to create an XML document
  • www.w3.org/wsdl

Intro to web services

• Application that can access by other application via the web
• It provides small amounts of functionality that r specific
• To use the functionality of web service – client app must exist
• Client app must reference the web service and must understand what to present to web service and what will return

1. Introducing ASP.NET 2.0 server control
2. Synchronous vs Asynchronous web application
3. Intro to the ASP.NET AJAX architecture
   1. An overview of the AJAX Library
   2. The Microsoft AJAX Library and web services
   3. Javascript Object Notation (JSON)
   4. An overview of the ASP.NET 2.0 AJAX Extensions

Summary

A lot of this may not make much sense right now, but don’t worry if you didn’t understand all the details we’ve just discussed. As you work through the examples in this book and see how elegantly ASP.NET AJAX script interacts with the underlying HTML and understand how the server-side controls eliminate much of the manual scripting, it will

become much clearer.

In this chapter, you were introduced to the overall architecture of ASP.NET AJAX, given a tour of the various features the architecture offers, and introduced to how it can empower the development of richer browser-based clients.

ASP.NET AJAX is based on two pillars. The first pillar is the client-portion, Microsoft’s AJAX Library, which encapsulates many common functions, provides an OOP environment for JavaScript developers, and enables access to ASP.NET Web Services. The second pillar is the ASP.NET 2.0 AJAX Extensions, which is a set of server controls that implicitly generates the JavaScript code that is needed to implement your AJAX application on the client.

2) State

4 type of state :

- Control State

- View state

- Session State

- Application State

3) View State

- is the state of the page and all its control

- auto maintain via a form field – this technique works with all browsers

- the info save in the hidden field is based64 encoded but not encrypted

4) Session State

5) Application State