Beyond HTML: Tools for Interactivity

Tool #4: Cold Fusion, ASP and PHP

Allaire’s Cold Fusion is a server-side solution for creating interactive, database-driven Web sites, as well as simpler built-in support for database queries. Cold Fusion is an application server, meaning it works in conjunction with a Web server to deliver Web applications, not just plain Web pages. You build Web pages that include special tags, which must be hosted on an application server that supports Cold Fusion. When a Web browser requests one of those pages, the application server first interprets the special tags, replaces those tags with the results of whatever calculations or database queries are specified, and then sends the completed page to the Web server, which finally sends it to the browser.

Cold Fusion uses a tag-based language—you mingle normal HTML tags with those of Cold Fusion Markup Language  (CFML). CFML includes tags for querying databases and outputting text, and interacting with other Web services such as email. Instead of ending your filenames with .htm or .html, you use the .cfm extension instead.

Microsoft's Active Server Pages (ASP), is a popular competing Microsoft product with similar functionality. Like Cold Fusion, ASP involves writing Web pages with mixed HTML and scripts. In ASP, those scripts can be written either in Microsoft's variation of JavaScript, called JScript, or in VBScript. ASP requires Netscape 4.x or above or IE 4.0, and works best with IE 4.0 and above.

PHP is a popular open-source tool with similar functionality, based on scripts embedded within HTML docouments. PHP distinguishes itself from both Cold Fusion and ASP in that it is entirely free.

Browser Support

• Cold Fusion and PHP do not have any browser limitations, unless you combine them with JavaScript.
• If ASP is run on the server side (most common), it is browser independent. If it is tied in with VBScript for client side applications, it is dependent on users viewing pages in IE.

What can these tools do?

Create dynamic data-driven web sites:

1. Interact with databases
   
   Example--University Programs Council Short Courses (ASP - Access Db)
   http://web.virginia.edu/upc-sc/courses.asp
   choose dance category, click on the + next to Irish Dancing
   
   Example--ITC Software Central (PHP - MySQL Db)
   http://www.itc.virginia.edu/desktop/central/
   Choose Windows 2000 Software, WS_FTP and Winzip Software Links
   
   
2. Create guest books, shopping carts, and order entry systems, including credit card processing
   
   Example--
   
   
3. Interact with a combination of Database and LDAP directory service (ASP - Access Db - LDAP)
   
   Example--ITC Research Center's statistical software license registration page:
   https://www.web.virginia.edu/rescomp/ldb/login.asp
   Login with your SSN and Last Name

Pitfalls

• Creating Cold Fusion or requires a strong understanding of both relational database design principles and HTML coding—a big leap for either database designers who haven’t done much web work or web designers who haven’t built many databases
• Cold Fusion and ASP require hosting on special servers that  have application server support—these are available at UVa, but require special accounts and in some cases, fees for hosting.
• Cold Fusion, ASP and PHP all require creating a relational database in another product— these products serve as the front-end  of a web database, not as the database itself. All interact with a number of database formats, including Access, Sybase, Oracle, SQL Server and MySQL.
• ASP is currently a PC-only solutions. PHP is commonly used on the UNIX platform, and Filemaker Pro is an option for Mac web database support.

Effect on System Performance

• Complex queries can slow response time.

Cold Fusion Resources

1. ITC provides a Windows 2000-based Cold Fusion Application Server for instructional content delivery, research, and departmental projects:
   http://www.web.virginia.edu
   
   
2. The introductory book favored by Cold Fusion professionals:
   The Coldfusion 4.0 Web Application Construction Kit, by Ben Forta
   
   
3. Macromedia has an extensive site, with help from experts, tutorials, and free downloads:
   http://www.macromedia.com/software/coldfusion

ASP Resources

1. ITC provides a Windows 2000-based ASP Application Server for instructional content delivery, research, and departmental projects:
   http://www.web.virginia.edu
   
   
2. ITC offers an Introduction to ASP course:
   http://www.web.virginia.edu/DOTWeb/itccourselist.cfm
   
   
3. There is a whole cottage industry of ASP books on the market:
   http://www.aspobjects.com/ASP_Books_Media/
   
   
4. Microsoft has an extensive site, with help from experts, tutorials, and free downloads:
   http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnanchor/html/activeservpages.asp

PHP Resources

1. ITC offers PHP Application Support on many of it's UNIX servers, including www.people.virginia.edu
   http://www.itc.virginia.edu/desktop/web/php.html
   
   
2. There are a wide range of PHP books available on the market:
   http://www.php.net/books.php
   
   
3. Extensive PHP support on the web is available at:
   http://www.php.net

Additional Web Database Resources

Go on to Tool #5 Java

Introduction | Tool Types
JavaScript | DHTML | CGI/Perl | Cold Fusion | Java