Web Design in a Nutshell, 3rd Edition

The object element began as a proprietary element in Internet Explorer to support ActiveX and later Java applets. Netscape Navigator initially supported only embed and applet (discussed later in this chapter) for embedding media, but added limited object support in its Version 4 release, and improved (yet still improperly implemented) support in Version 6. The W3C intends the object element, now part of the HTML 4.01 and XHTML Recommendations, to be a replacement for the more specific img and applet elements as well as the nonstandard embed and bgsound (used for background sounds).

The attributes required for the object element vary with the type of content it is placing. The object element may also contain a number of param elements that pass important information to the object when it displays or plays. Not all objects require additional parameters.

The object and param elements work together to allow authors to specify three types of information:

The implementation of the object.

That is, the executable code that runs in order to render the object. This may be a tool or player required to display an external file (such as the QuickTime plug-in for showing a .mov file), or it may be the object itself, such as a self-contained clock applet. The implementation is specified with the classid attribute.

The data to be rendered.

The data attribute specifies the URL of the data; in most cases, an external file, such as a movie or a PDF file. According to the HTML 4.01 spec, the data attribute ...