Making Active Web Pages

Making Active Web Pages

Some web pages are very static. They just sit there and display information. Their interaction with the user is limited to working with the scroll bar(s), and eventually clicking on a link or the back-button to go somewhere else. There is no great kinetic sense in using such pages. Other pages change, either by themselves, or by encouraging user actions and by providing prompt responses. Such active web pages try to engage to user.

• Active Web Pages
  • Provide text or images:
    • With content that depends on user input; or
    • With content that changes without user input
  • Animations
  • Interactive forms
  • Database queries
  • Drill programs
  • Choice of pages to display that depend on prior user activities
  • Makes web browsing more varied and interesting than walking through static trees of web pages
  • If overdone can be distracting and confusing
• Actions supported on the client
  • Built-in browser functions
    • Animated GIFs
      See Web Diner GIF Animation Tips
    • Timed redirections
    • Mailto:
  • Helper applications
    • Keyed to file extensions
    • Music, Movie and graphics applications
    • Word processing
    • Can create security holes
  • Plugins
    • More intimately tied to the browser than helper applications
    • Music, Movie and graphics applications
    • Acrobat
    • Flash
    • QuickTime
  • Javascript
    ( see w3schools JavaScript Tutorial.)
    • A simplified java interpreted as part of each web page
    • Solid text, minimal graphics (canned images only)
    • Can rewrite the html text of the web page on the fly
    • Can prompt for information or extract it from forms
  • Java
    • A full programming language with sound security model
    • Works with its own sub-windows of the main window
    • Complex text manipulations
    • Makes interesting animation
  • Other client-side active web page support
    • Visual Basic, VBScript, ActiveX
    • ...
• Actions supported on the server
  • Common Gateway Interface (cgi-bin)
    • Any script or application that can run on the host
    • Perl, Java, ...
    • See CGI Forms
    • See Apache CGI Tutorial
  • Server-Side Include (SSI)
    • Server rewrites web page before sending it
    • Used for counters, date/time displays
    • Can invoke cgi-bin scripts
    • See Apache SSI Tutorial
  • Java Server Pages (JSP) and servlets
    • Build web pages on the fly
    • De facto standard for database interactions
    • java-based
    • Complex, powerful system
    • Needs a hefty server
    • See Marty Hall's Servlet Tutorial
    • See www.jsptut.com
    • See Apache Tomcat Tutorial
  • Cascading Style Sheets (CSS)
  • Other server-side support
    • Active Server Pages (ASP)