Webnet :: Meeting Handout :: Microsoft Active Server Pages

Overview:

Microsoft Active Server Pages

Tim Heidinger, Pandelis Tiritas
University of California, Berkeley
Undergraduate Affairs

Overview

Microsoft® Active Server Pages (ASP) is a server-side scripting environment that you can use to create and run dynamic, interactive, high-performance Web server applications. When your scripts run on the server rather than on the client, your Web server does all the work involved in generating the Hypertext Markup Language (HTML) pages that you send to browsers.

Requirements

Active Server Pages is a feature of and can be used with the following Web servers:

Microsoft Internet Information Server version 3.0 on Windows NT Server
Microsoft Peer Web Services Version 3.0 on Windows NT Workstation
Microsoft Personal Web Server on Windows 95
OāReilly Website 2.0

A third party company is developing ASP support for a number of other Web servers. (Chili!Soft http://www.chilisoft.net/)

All the Web servers that support Active Server Pages require Windows NT or Windows 95, and as a result such a machine running one of the two operating systems is required to run Active Server Pages.

Database Connectivity

The most common method to access data with ASP scripts is to use the ASP Database Access component. The Database Access component uses ADO (ActiveXÔ Data Objects) to access information stored in a database or other tabular data structure. Any data source that has an ODBC driver can be accessed with ADO. The features supported for each data source depend on the capabilities of individual ODBC drivers. There are drivers for most database back-ends and desktop formats, including Oracle, MS SQL Server, Sybase, FoxPro, Paradox and dBase.

The ability to extend ASP with ActiveX controls opens some interesting possibilities for other methods of accessing data sources. For example, one could create a Visual FoxPro program that does all the data access using VFPās extremely fast database engine, save it as an ActiveX component and use it from within ASP to run queries against a FoxPro database.

Development Environment

Microsoft offers a product called Visual Interdev (Wareforce: License ~ $37, CD $17, Docs: On-line) , which is a visual integrated development environment for building ASP applications. Visual Interdev has the following features:

Visual design-time controls automatically generate the HTML and scripting logic necessary to create database-driven Web sites. This feature is not as complete as it is in other similar products and only covers a subset of the scripting that needs to be written for a complete internet application.
Query Designer feature allows developers to visually construct and test even the most complex SQL statements for your Web site.
Data Form Wizard lets developers quickly build customized, data-bound HTML forms in a matter of seconds.
FrontPage Editor Visual Interdev Edition facilitates visual editing of HTML files.
Text editor with syntax highlighting is ideal for editing ASP files and for finer-grain control over HTML files.
Content editing tools facilitate creating, editing and publishing Web images and musical effects.
Integrated site management and site visualization system makes it easy to deploy and manage complex Web sites. The "View Links in WWW" feature provides a graphical representation of a Web siteās structure indicating the relationship between the various files and making it easy to spot broken links.
Extensive samples, help, and online resources are available for rapid learning and quick answers to common questions. The help files provided cover ASP, the Visual Interdev Interface, MS SQL Server, HTML, ADO, Javascript and VBScript.
Data View feature provides a live view into all databases used in a Web site.
Database Designer feature provides point-and-click database administration for Microsoft SQL Server 6.5 databases.
Team development support allows multiple users to work on shared network Web sites at the same time, and includes optional integration with Microsoft® Visual SourceSafe for safe check-in and check-out of files, and revision management.
Works with Microsoft FrontPage 97 Web authoring and management tool so that non-programmers and programmers can work simultaneously on the same Web site, each using a tool tailored for their specific needs.

Pros

You can use ASP to include executable scripts directly in HTML files. HTML development and scripting development become the same process, enabling you to focus directly on the look and feel of your Web site, weaving dynamic elements into your pages as appropriate. ASP applications are:

Completely integrated with HTML files.
Easy to create, with no manual compiling or linking of programs required.
Object-oriented and extensible with ActiveX server components.

ASP applications are easy to develop because you use ASP scripting to develop them. With ASP scripting, you can use any scripting language for which you provide the appropriate scripting engine. ASP supplies scripting engines for Microsoft® Visual Basic® Scripting Edition (VBScript) and Javascript. You can incorporate sophisticated functionality using ActiveX server to process data and generate useful information.

Unlike the limited macro-like languages found in other products, ASP can use real scripting languages such as VBScript and Javascript, which offer the programmer a lot of power. The ability to choose between different languages and the popularity of the two included by default increases the chance that you already know how to program in ASP.

ASP solves the notorious problem of "keeping state" by sending a session id in the form of an HTTP cookie each time a browser calls an ASP application for the first time. The interface allows programmers to maintain session-scope variables (including data-bound objects) that are maintained between successive hits.

ASP-generated content is compatible with standard Web browsers.

Cons

Even though ADO is extremely powerful, it is not as easy to use at first as similar interfaces in other products such as WebDBC. Users need to gain a fairly complete knowledge of the ADO object model in order to use the interface effectively. The upside is that ADO exposes the full power of ODBC to the programmer so there is almost nothing that can not be done with a little bit of programming.
The script generating wizards of Visual Interdev are not as extensive as the ones found in other products. Fortunately Microsoft exposed the wizard interface to third party developers, so more wizards should begin to appear in the future.
Nobody should realistically expect direct support from Microsoft given the size of the company and it current practices. Fortunately there are several other sources of information and at least one very busy newsgroup devoted exclusively to ASP.

The Future

Microsoft IIS 4.0, currently in beta 3 will add new features to Active Server Pages that will make it even easier to deploy reliable and scalable multi-user Web based applications:

Crash Protection - Crash Protection allows customers to run multiple applications reliably on the Web server. If one application crashes, the Web server and other applications will continue to run, and the failed application restarts upon the next request.

Transacted Active Server Pages - IIS 4.0 introduces Transactional Active Server Pages, which allows applications with scripts and components to perform multiple actions, with all actions committed together, or none at all. This is critical for database applications.

Script Debugging - IIS 4.0 provides an integrated solution for debugging Active Server Pages scripts and applications making it easier to develop ASP applications.

Integrated Message Queuing - Microsoft Message Queue Server (MSMQ) provides an easy way for applications to reliably send and receive messages over a network - even in the event that part of the application or the network becomes unavailable.

Support for Java - IIS 4.0 Beta 3 includes a set of Java classes to build server-side components and Microsoftās Java Virtual Machine, which has been tuned for them. Using Active Server Pages and Microsoft Transaction Server, you can easily build server applications using Java and run them efficiently in the demanding server environment.

ASP Code Sample

The following code sample opens a connections to an ODBC data source called ADOSamples, creates a record set based on a SELECT statement, loops through the fields to display field names, and then loops through each record, displaying all fields in an HTML table. Finally it closes the record set and the connection, and exits. Notice how ADO allows looping through a record set without prior knowledge of field names by using the fieldās index number. Alternatively, the code could specify the field name in the form RecordSetName("FieldName").

Text in bold type is VBScript code. Text following a "ā" is a comment.

<HTML>
<HEAD>
<TITLE>ActiveX Data Object (ADO)</TITLE>
</HEAD>
<BODY BGCOLOR=#FFFFFF>
<H3>ActiveX Data Object (ADO)</H3>
<%
Set Conn = Server.CreateObject("ADODB.Connection")
Conn.Open "ADOSamples" 'ADOSamples is the name of ODBC the Data Source
Set RS = Conn.Execute("SELECT * FROM Orders") 'Create record set
%>
<P>
<TABLE BORDER=1>
<TR>
<% For i = 0 to RS.Fields.Count - 1 'Loop through fields%>
<TD><B><% = RS(i).Name 'Display field name%></B></TD>
<% Next %>
</TR>
<% Do While Not RS.EOF 'Loop through each record%>
<TR>
<% For i = 0 to RS.Fields.Count - 1 %>
<TD VALIGN=TOP><% = RS(i) %></TD>
<% Next %>
</TR>
<%
RS.MoveNext
Loop
RS.Close
Conn.Close
%>
</TABLE>
<BR>
<BR>

</BODY>
</HTML>

Undergraduate Affairs ASP Applications

Student Registration Status on the Web

http://registrar.berkeley.edu:4202/regweb.html

Displays registration status for any UCB student, replacing the registration sticker on student id cards. Functionality includes password protection for restricted display options, limiting restricted options to ".berkeley.edu". (VisualFoxPro and Oracle)

Career Center

http://career.berkeley.edu/

Calendar and event applications. Staff data-entry pages to update the database. Using ASPMail to provide SMTP mail functionality to an application that allow students to subscribe to constituent groups. (MS SQL Server) Developed jointly with the Computer Assistance Program (http://www-oms.berkeley.edu/cap/).

UGA Report Factory

Currently underdevelopment in pilot status. Provides authorized staff with a web-based reporting tool that generates HTML reports, formatted 3 up address labels, and simple e-mail interface. (Oracle)

Kerberos Authentication

We are currently attempting to develop a way to easily add Kerberos authentication to ASP applications.

URLs

ASP Support:

About ASP:

About ADO:

Tutorials: