Clipping the Web so it fits in the palm of your hand

Last week, Gearhead enthused about the way-cool 3Com Palm VII with built-in wireless e-mail and Web access. For corporate use, this could be a phenomenal tool to keep mobile users up to date and provide access to corporate resources.

As we discussed, the problem with accessing Web content on the Palm via wireless services is that the average Web page is just a bit overweight for a device with 2M bytes of memory.

Just to make the constraints on the system really tricky, the content display area for HTML pages is only 153 by 144 pixels. Using the normal Palm font, only 11 lines can be displayed at a time. Add to that the limitations of Palm's wireless data transfer rate (8K bit/sec) and the cost of the wireless service, and some serious optimization is required.

3Com's answer is a technology called Web Clipping. Web Clipping defines a Web page variant to ensure that the Palm's memory and communications resources aren't exhausted or otherwise abused. The system consists of the Web Clipping application in Palm VIIs (in effect, a Web browser) and a proxy server that mediates access to Web sites. The Web Clipping system not only supports HTTP access, but also provides secure access using HTTPS.

The process of Web Clipping uses something called Palm Query Applications (PQA). PQAs are applications loaded onto the Palm VII that define how to access a specific Web site. PQAs are easily built: They consist of HTML pages and associated graphics compiled using a utility called the Query Application Builder (this is really easy to use). The HTML content retrieved from the Web and in the PQAs is actually a subset of HTML 3.2 that excludes JavaScript, nested tables, frames, cookies and Java applets.

When you run a PQA (in fact, the PQA is read and interpreted by the Palm VII's Web Clipping application), the initial content you see is local, so there's no associated access cost. The PQA usually also includes the Help and About pages. The index page content is usually structured so you choose a link and go to live information out on the Web.

The only problem with this approach is that if you have new content you want people to see, you need to distribute a new PQA or include the link somewhere in your live content.

There are four special HTML metatags that Web pages need to use to provide Web Clipping-suitable content: The PalmComputingPlatform tag identifies a page as a Palmfriendly page; without this tag, inline images will not be rendered and only the first 1,024 bytes of text will display.

The HistoryListText specifies the name of the page to be displayed in the history pop-up menu, and PalmLauncherRevision sets the version for a query application.

The metatag LocalIcon is used only in PQAs and indicates to the Query Application Builder that an image or a Web page is to be stored in the PQA. Content retrieved from the Web can refer to the local content stored in PQAs.

Other Web Clipping features include a cookie-type system; the ability to determine the zip code of the wireless base station the Palm is accessing; and special tags including SMALLSCREENIGNORE, which marks areas in Web content to be removed by the Clipping proxy server so they aren't displayed, and BUTTON, which produces a labeled hyperlink button on the Palm screen.

There are a few more Web Clipping features, but we've covered the major details. What Gearhead really likes about this technology is that it is simple and works well. If you have mobile users, you might think about getting them Palm VIIs so you can give them instant and simple access to corporate systems.

If you generate a cool PQA, tell Gearhead about it. Flip a clip to gh@gibbs.com.