Active Server Pages

ASP has other meanings. See its disambiguation page.

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, it's 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, it is best not to open and close asp tags <% %> often, as 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

Wikibooks has more about this subject:

Active Server Pages

Categories: Internet | Microsoft