Peter Troon - Active Server Pages

Active Server Pages

The development of the internet during the last years required the possibility to create web pages with dynamic content. Many sites have pages with content that changes everyday or sometimes even every hour. For instance websites with stock shares or sites providing the latest news change all the time. You can understand that it would not be very practical to update all these pages manually, because this would be a time consuming job. Not to mention that the chance to make mistakes is much bigger if these pages are changed manually.

But not only news sites have dynamic content. Basically any page that has some kind of interaction with the user is dynamic. The page has to be dynamic, because nobody can predict what the user will do. The page will behave in a certain way depending on the reaction of the user accessing that page. The most common dynamic pages are pages that are used to validate forms. For instance: a page gives a visitor of that site to subscribe to the mailing list of that site. The visitor needs to fill in his name, his e-mail address and some other data. When the user submits the form (by pressing the submit button) the data is validated before the results of the submission are processed. If the visitor has to fill in his e-mail address the page will check if the e-mail address was filled in and if it's filled in in a proper way. Thus it checks for instance if the filled in e-mail address contains the @-sign. Depending on the checks performed after submission by the user a message will be displayed that the submitted information will be or has been processed or that the information provided is invalid or not complete with the possibility for the user to correct his mistakes.

The combination of the languages Perl/CGI made it possible to extend websites with the possibility to have pages with dynamic content. Perl/CGI have the major disadvantage not to be efficient with the available sources. Because CGI was one of the first languages, which made it possible to make page dynamic almost any webserver is able to execute CGI scripts. Later on other scripting languages such as ColdFusion and ASP became popular. ASP stands for Active Server Pages and was developed by MicroSoft.

Just like ColdFusion and PHP, ASP provides the possibility to fully integrate ASP code into HTML pages. The server on which the ASP template is stored needs to be able to execute ASP scripts. Microsoft provides webservers capable of executing ASP scripts. In more professional environments (such as Microsoft Windows NT or Microsoft Windows 2000) Microsoft Internet Information Server (IIS) is used. For Windows 98 Microsoft Personal Web Server (PWS) is available.

ASP uses Visual Basic Script (VBScript) or JScript to display dynamic content. So actually ASP in itself is not a real language. For persons with some programming experience ASP shouldn't be that hard to learn. ASP has a few standard objects which can be accessed by the programmer. A person new to ASP has to learn how to access these objects and what the purpose of each of those objects is. It is also possible to create additional objects, but in most cases this should not be necessary, because many custom made additions are available on the internet. Why write something that is already available and re-invent the wheel? Unless you have a very good reason to do so it is not recommended for a beginner to start creating custom made objects.

An ASP web application can be linked to a database. In many cases it is combined with a Microsoft Access database. If the application is quite small and not many people will be using the application this is a nice solution. For large applications this is not recommended though. Microsoft Access was never meant to be used as a database for large applications. In those situations you're better of using a professional database such as Microsoft SQL Server or Oracle.

This page just provides some general information about ASP. If you want to learn more about this language you should check out the links below.

Active Server Pages

Links

Note: This page is part of the Peter Troon Site.