5.  What goes on my page?

What can I do on my own?

• Documents based on existing printed publications. Depending on the word processor or desktop publishing software used to create them, you may be able to perform the initial translation to HTML by an appropriate choice within the "Save As..." dialog box. At worst, you will need to copy and paste from another application into your growing HTML file in your word processor.

• New text documents you create, just for the Web.

• Standard graphic images can be included by typing the correct references into the HTML file.

• Shortcuts for navigation among your files can be included in text form as just another link within your HTML file. Shortcuts in imagemap form will require just a little bit more work on your part, above and beyond the creation of the image to be used.

• You can create and use very simple forms as part of your HTML file.

What can I do with an artist's help?

• Fancier and custom graphics may call for image manipulation software you don't have, or for skills that you don't have for using the software, or for aesthetic judgement you have not yet acquired.

• Images to serve for shortcut imagemaps will usually benefit from preparation with Photoshop or a comparable advanced image manipulation package that has multiple layers in the working file, even though the final image is of course a single layer. Keeping the text overlay in its own layer makes revision much easier.

• A scanner can be used with a wide variety of image manipulation software to create image files from drawings and photographs.

• Sound clips need to be captured or recorded with care, bearing in mind the limitations of the equipment that may be used to reproduce them.

• Video clips likewise need to be captured or recorded with care, bearing in mind the limitations of the equipment that may be used to reproduce them. Limitations to be aware of include
  • Frame size (320 x 240 pixels is also known as "quarter-screen," for example);

  • Colors per pixel (256 colors are provided by 8 bits per pixel; it takes 16 bits per pixel to even come close to matching the color discrimination of the human eye);

  • Frame rate (30 frames per second will provide smooth motion).

What about CGI and JAVA?

When you work with a programmer on a web-based project, there are two possibilities:

1. The program may be executed on the server, with the web browser providing the user interface. This is routinely provided under the name "CGI scripting."

   CGI scripting works well in a situation that will involve a modest number of simultaneous browsers. If too many people run the program at the same time, the server system will be brought to its knees, slowing down or even preventing the presentation of other web pages from that server.

   The CGI program may execute on the server with the identity of the web server, in which case it will have access to a great many files on the system. In such a case, there will need to be appropriate precautions to ensure the integrity of the system.

   The CGI program may execute on the server with the identity of the individual authorized user who wrote it. In this case, the CGI program will have access to all files on that server that are owned by that user, including any personal E-mail files that are kept on that system.

2. The program may be executed on the browsing computer. This is available with some recent browsers using Sun Computer's "JAVA."

   JAVA has the advantage over CGI that the available resources for executing the program grow in exact proportion to the number of people running it, instead of being constant.

   The disadvantages of JAVA include the following:

   • Browsers run on all sorts of hardware and software, so providing access to the intended functionality will depend on the availability of a JAVA-capable browser for the particular hardware and operating system that the user already has on his or her desktop. Many people will continue to use pre-JAVA versions of browsers because they have too little RAM or because they only have free access to the old version.

   • The JAVA program will be executed on the browsing system. It is a real computer program, and will therefore be able to try to do anything. If the browser has been flawlessly written, it will prevent the JAVA program from doing anything nasty. Many people who have JAVA-capable browsers will configure them to leave JAVA turned off because they don't trust the browser to be bug-free. This is a realistic fear. At least one version of Netscape has been released that permitted a JAVA program to erase files from the user's hard disk.

What can I do with a programmer's help?

Full-blown forms: in general, the information provided by the user of a form is processed by a CGI computer program. In some cases, such as search engines, the resulting output is sent back to the browser as HTML, to be formatted for display. In other cases, such as a guestbook, the information can just be stored away for use by the publisher of the Web page.

The CGI program may provide database access for updates, for revisions, or for reports, such as the class schedule we looked at earlier. These "Real Applications" may well be a trend for some time to come, permitting application programmers to concentrate on their application, and using the web browser as a universal user interface.

Dick Piccard revised this file (http://ouvaxa.cats.ohiou.edu/~piccard/oacrao/pages.html) on November 12, 1996.

Please send comments or suggestions to piccard@ohiou.edu.