Active Server Pages (ASP) is Microsoft's server-side technology for dynamically-generated web pages that is marketed as an add-on to Internet Information Services (IIS).
Programming ASP websites is made easier by various built-in objects. Each object corresponds to a group of frequently-used functionality useful for creating dynamic web pages. In ASP 3.0 there are six such built-in objects: Application, ASPError, Request, Response, Server and Session. Session, for example, is a cookie-based session object that maintains variables from page to page. Application Test Center is also available for load testing.
Most ASP pages are written in VBScript. Other scripting languages can be selected by using the @Language directive. JScript (Microsoft's implementation of JavaScript) is the other language that is usually available. PerlScript (Perl) and others are available as third-party add-ons.
Versions
ASP has gone through four major releases:
- ASP 1.0 (distributed with IIS 3.0) in December 1996,
- ASP 2.0 (distributed with IIS 4.0) in March 1998,
- ASP 3.0 (distributed with IIS 5.0), and
- ASP.NET (part of the Microsoft .NET platform). The pre-.NET versions are currently referred to as "classic" ASP.
ASP.NET introduced the ability to replace in-HTML scripting with full-fledged support for .NET languages such as Visual Basic .NET and C#. In-page scripting can still be used (and is fully supported), but now pages can use VS.NET and C# classes to generate pages instead of code in HTML pages.
Examples
Pages can be generated by mixing server-side scripting code (including database access) with HTML and client-side code. For example:
<%
' this line does nothing its just a comment the next line does:
Response.write "Wikipedia" ' This code writes out Wikipedia to the browser
%>
<%
Dim x 'Make sure to always dim your variables
x = 1 'x is our variable in this example
If X = 1 Then
%>
<b>X equals one</b>
<% Else %>
<b>X is not one</b>
<% End If %>
For more efficiency its best not to open and close asp tags <% %> often this causes the ASP engine to have to turn on and off.
- For example, a more efficient solution would be:
<%
Dim strWikiPedia
strWikiPedia = "free"
'# this example uses pure ASP VBScript to get the job done...
If strWikiPedia = "free" then
Response.write "stick around and enjoy without entering in a credit card"
Else
Response.write "get out your credit card. Or click a banner."
End If
%>
The code between the <% ... %> delimiters will be processed by the server. The resulting HTML is <b>X equals one</b> when the server-side variable X = 1.
External links
