|WebTV Frames Things a Different Way
Frames-based pages can work great for WebTV users, but a few eccentricities can sneak up on an unwary developer, rendering some pages dramatically different than what the author intended. This article will attempt to explain both the reasoning behind the WebTV browser's interpretation of frames as well as the specific issues that this implementation evokes.
Optimizing web pages for a television screen makes it very difficult for WebTV to support frames in the same way that a computer browser does. Due to navigation and television resolution issues1, it became clear that the WebTV browser would need to modify frames for the sake of a pleasant user experience.
WebTV supports frames by "breaking them out" into a table. This means that all of the content within the frames will be displayed, but no individual frame will remain static. Here is an illustration of what a user might see on a frames-based page that she visits.
1. Frames are turned into a table.
Since the frames were essentially turned into table cells, the top frame scrolls off the top when the user pages down. The content of the left-hand frame has gone off the top as well.
2. Frame sizes are determined by content.
The WebTV browser allocates frame size according to a given frame's content. To see an example of this, let's look at an example where the green and blue frames are "content-heavy":
WebTV Classic boxes have some eccentricities.
There are several different versions of the WebTV box, the WebTV Classic and the WebTV Plus. While the browsers that the two boxes use are very similar, there are occasionally discrepancies in how they perform. The "Classic" box is much more sensitive to "content-light" frames, and will truncate frames accordingly. Example:
Some Guidelines for WebTV and Frames
In the vast majority of cases, the WebTV browser handles frames
admirably, with a minimum of mangling. There are, however, a few guidelines that you may
want to consider as you design your frames-based site:
1 There are two main reasons why the WebTV browser does not implement "scrolling" frames. First, the poor resolution of a television does not happily lend itself to having its real-estate divided up into even smaller frames. Second, The WebTV interface does not use a cursor. Thus, there is no convenient way to scroll through or resize individual frames. WebTV users navigate the Web with a selection box that highlights the links on a page, or with scroll buttons that can page through content. Only on imagemaps, where a cursor is absolutely necessary, will WebTV users see a "traditional" pointer. It is then controlled with the arrow keys. Moving out of the image map will cause this pointer to disappear. Back to where you were.
2 The astute reader will note that I did not tell you the name of this WebTV proprietary tag. The main reason for this is that once you start publicizing these things, you've got to answer all the questions about them. For this reason, it remains undocumented. That being said, its use has leaked out over time, and the adventurous reader may be able to hunt down this tag (among many others) for late night HTML experimentation. Just don't say I didn't warn you.