Creating a simple ASP page in VS .NET

Encoder UPC Symbol in VS .NET Creating a simple ASP page

This chapter won t tell you everything there is to know about ASP The main focus of this chapter is to show you can use ASP with FrontPage ASPNET For Dummies by Bill Hatfield (Wiley) provides a full explanation of all the ASPNET nuances The example is relatively simple so that everyone can use it without knowing a lot about ASP The example does show some ASP features though so you can see that FrontPage is a true ASP development environment

Working with ASP in FrontPage isn t as straightforward as it could be in some respects The problem is that FrontPage assumes every Web page you create has an HTM extension ASP requires use of the ASP extension To create other kinds of files, you must change the extension Here s how:

extension FrontPage creates a new ASP page The new ASP page has a different icon than a standard HTM page, so you can readily identify it The SimpleASPASP file included with the source code for this chapter on the Wiley Web site shows how this type of page appears in FrontPage

This is a situation where creating your own templates really pays off (See Book II, 5, for details) You can create a blank ASP page that includes the basic information these pages require It s also possible to create ASP pages with some content already defined Be sure to include a preview of the page as it appears to the end user rather than the script view you see when working with the page

Design the ASP page as you would any HTML page You can create blanks on the page that ASP automatically fills in for you (using script to do so) The page can also accept input and modify the data that the user provides As you design your Web page, think about the data you want to see displayed on the page rather than the technique used to display it Make sure you provide a means to read content as well as write it back out to the page Normally, you use a form and form controls to gain access to the information the user provides However, you can easily use other techniques to interact with the user When you want to display information rather than obtain information from the user you can rely on paragraph tags An ASP script can also interact with objects, so you can use standard FrontPage objects or create objects using the <object> tag Use this alternative carefully because it adds complexity to the Web page design and the scripting you need to perform This option also provides a lot of flexibility, and you can perform tasks, such as create interactive video, that simply isn t possible using any other technique

After you design your page, you make it dynamic by adding script elements to it A script element need not be complex or hard to understand All you need is the right keywords Microsoft provides a complete reference of ASP keywords at

Some of the most common keywords include those that request information from the client or the server Here s an example of a server request

Every ASP script appears within the <% %> characters This script tells the server to write some information to the client You use the Response Write() script command to write anything that ASP can write to the client The information this code writes is a server variable the server name Use the RequestServerVariables() command to discover information

about the server To discover all the keywords your server understands, ask for each keyword in turn, like this:

<% for each Value in RequestServerVariables %> <% if not RequestServerVariables(Value) = then %> <p> <%= Value %> :  <%= RequestServerVariables(Value) %> </p> <% end if %> <% next %>

This code tells IIS that you want to look at each value provided with the RequestServerVariables collection A collection is a set of information that you can access using the server The next statement tells IIS to ignore any server variable that is blank This line is necessary because when someone accesses your Web page in anonymous mode, many of the possible server variables are blank The variable Value has received a server variable name as part of the <% for each Value in RequestServerVariables %> statement The code can send this value as part of the response using the <%= Value %> statement The equal sign in this statement takes the place of the Response Write() script command Notice how the code uses a special character, the nonbreaking space ( ) to provide a space between the value name and the actual value The code also uses Value as input to the RequestServerVariables() script command, which prints out the value contained in that server variable Notice that the <% if %> statement ends with an <% end if %> statement, and the <% for each %> statement ends with a <% next %> statement You always tells ASP where a statement begins and ends so ASP knows when to start and stop a series of commands Figure 6-5 shows an example of some typical server variable values Some of this information is pretty interesting For example, the REMOTE_ADDR server variable tells you the client address so you can keep track of which client is requesting information The PATH_TRANSLATED server variable shows the actual path to this script on my server Sometimes you need to know this information so you can access files on the server s hard drive Move down the list and you can get a look at some information about the server The SERVER_SOFTWARE server variable tells you which operating system and Web server the server is running so you can address any compatibility needs