ASP.NET 3.5: A Beginner's Guide - www.mustafaof.com

Chapter 1: Introduction to ASP.NET 3.5 9From Client Side to Server SideAs you saw in Figure 1-2, all that the web browser does is make requests to the server andreceive web pages in the form of HTML. The browser takes the HTML and constructs apage for viewing on your browser. For the most part, that’s what will continue to occurwhen you adopt ASP.NET. The main difference is that by writing and executing serversidecode, you can generate HTML that effectively handles dynamic states so that you canuse and reuse a given state. Figure 1-3 shows the general flow when an ASPX file on aMicrosoft server receives a call from the client.In looking for an example, we need look no further than the original example of theHTML page with the form. With a server-side program to catch the data that is sent tothe server, lots of processes on the server are possible. Suppose the user enters the name,Willie B. Goode. The server-side file can use the property name, username, to extract avalue. In this case, it would extract the name Willie B. Goode and do something with it. Itmight run a SQL script to store the name in a database, compare it with a password, or itcould pass information about Willie B. Goode back to the browser in HTML.To get an idea of the differences and similarities between HTML and ASP.NET, wecan take the HTML form and add a calculated response from the server. In this nextexample, you will see two scripts. One is the ASP.NET script and the other is the C# codeusing a code behind file to serve as the event engine for the application. The form tagincludes a name and the coderunat="server"Data reference to ASPX fileASPX fileClientBrowserServer executescode; resultsconverted to HTMLand returned to clientReturns HTMLServerFigure 1-3 Server-side script