Web Whiz Bang: The Pros and Cons of Adding FLASH to your site

Interaction, Changing the page dynamically

There are two approaches to making a web page interactive:

1. embed interactive objects in an otherwise static page (plug-in, java applet)
   • embed a java applet
   • embed a plug-in file (e.g. Director, QuickTime Virtual Reality, ToolBook, SuperCard)
2. include a program in, or call on a program from, the page (javascript, cgi)
   • call a CGI script from your page
   • include a JavaScript script in your page
     

   Java

   is a programming language whose programs browsers can run
   allows browser to download and run programs as needed instead of downloading and configuring a certain plug-in and then downloading the program files

   • author has to know how to program in Java, which is more difficult for most people than scripting languages like JavaScript
   • to minimize code size: requires good programming practices
   • server has to be configured to serve java applets
   • user has to have version 3 or 4 browser, but no additional downloading, configuring or RAM
   • the java applet(s) can be quite large (100s of Kilobytes)
     

   *Plug-In Environment

   a version of a different program that is embedded in your browser
   adds functionality to the browser, allowing it to display files it otherwise couldn't handle
   used to create interactions or animations as specialized or sophisticated as the source program

   • author has to own the appropriate authoring program and know how to create material in it; possible to exploit existing material and programming expertise
   • to minimize code size: requires good programming practices
   • server has to be configured to serve the material's file type
   • user has to download the appropriate plug-in and configure his or her browser
   • the plug-in can be large to download and require lots of RAM to work (e.g. Shockwave, the plug-in for Director, requires 2.5 megabytes in addition to what the browser already requires)
   • the file containing the material can be quite large (100's of Kilobytes)
     

   CGI (Common Gateway Interface)

   A program that exists on the server. Information is sent from your page (usually from a form) to the server where it is acted on and then the results are sent back to the page. Typically used to search databases and return text or an html page, and not to change the existing page dynamically. Appropriate where you have a large amount of data that you want available for searching (e.g. text summaries of an audio/video collection with call number of original tapes). Not appropriate for typical "interactive" language learning exercises.
   

   *JavaScript

   designed to control elements and interact with form input on a web page, rather than create a separate special object (programmable environment) embedded in the page
   allows programs to be included with the page, rather than as a separate downloaded file.

   • author has to know how to write JavaScript - scripting
   • no problems with server
   • user has to run version 3 or 4 of Navigator or Explorer for some JavaScript features

   JavaScript can control browser behaviour and content but cannot draw graphics or perform networking. Java has little control over the browser, but can do graphics and networking.