Elements of Hypermedia Design - 39.3 Automation of the Development Process

39.3 Automation of the Development Process

Timeliness is a critical feature for conference proceedings, as conference attendees are used to getting printed proceedings at the beginning of the conference. This means, that talks to be disseminated should not appear years after the conference, but be published weeks to at most months after the conference. Turnaround-time for the CD-ROM-based DAGS'92 and DAGS'93 multimedia proceedings was at least one-year. For DAGS'95 we intended to greatly speed up the development process. This was possible because we now knew much better what material to collect based on previous experience. Additionally, the burden of hypertext (HTML) authoring was placed on the author and not on the production team. Also, we tried to automate the development process as much as possible by developing some production tools. The most important tool we implemented was "A Web Conference Factory" (AWCF), a HyperCard stack that automatically creates all of the HTML and auxiliary files for the digital talks.
Talks screen design: static versus dynamic approach
To emulate the "random talk access" feature of the DAGS'92 and DAGS'93 proceedings, we considered both static and dynamic approaches. The dynamic approach would have included the use of CGI/Perl scripts to generate HTML on the fly to display a particular slide. The CPU load on the server would have increased with the number of users accessing the talks, thus slowing down response times. The static approach, on the other hand, entails advance generation of many short HTML files, one per slide. As the HTML files are easily computed in advance, and as performance on the web is usually poor anyway, we opted for placing static short documents on the server instead of relying on dynamic page generation.
Talks screen design: final implementation
Our final screen design required that each slide would be mounted on a separate page (see figure IV.16), i.e., a different HTML file. The HTML file displays the actual slide title in the list of contents in italics, and also brings up appropriate control panel and slide images. The control panel (an image in interlaced GIF format) has to be produced for every slide because the correct number of sound buttons and the title of the slide have to be displayed. Besides HTML files, a WWW page relying on an imagemap also requires a ".map" file to correctly react to clicks within the image. For the generation of HTML, imagemap references (text), and dummy control panel files we developed the "AWCF" HyperCard stack (see below).
A typical one-hour talk in which 30 slides are shown requires the following:

Around 90 sound clips.
30 interlaced GIF images of slides (our screen design allowed for a maximal image width of 287 pixels with at most 256 different colors).
30 control panel GIF images.
30 HTML files.
30 map files (which contain individual sets of URLs for each slide).
AWCF ("A Web Conference Factory") functionality
Out of the totally 210 files, 30 HTML, 30 map and 30 dummy control panel files are generated by AWCF. This means that AWCF relieves electronic proceedings editors from having to manually edit HTML text and from having to use an imagemap tool to manually assign links to clickable areas of an image. Furthermore, it associates each slide with a set of sound clips.
To generate the GIF control panel image files demands the extra step of using dummy files created by AWCF to compute the final images. The dummy files contain the slide title, the number of sound icons required for the slide, and the slide number. The actual control panel images are generated in an additional batch process using the commercial graphics manipulation program DeBabelizer(TM).

Figure IV.24 AWCF user interface

AWCF requires the following input:

Title of the talk.
Full name and home page URL of the speaker.
Table of contents of the slide titles.
Number of sound files for each slide.
File name suffix for the files to be generated.
Path information to define an appropriate directory structure on the designated server.
Path information to tell AWCF where to place the generated files.

The output path can be selected individually for the HTML files, the map files, and the graphics files. Final production preparation requires the slide images to be resized to fit below the control panel and the format to be changed to interlaced GIF. This process can also be executed automatically by DeBabelizer(TM).