Summary

Embedded objects provide the means with which you can expand the capabilities of your pages to include advanced processing, network, and multimedia tasks. Web browsers support Java applets and ActiveX controls and/or Netscape plug-ins. JavaScript can interact with all forms of embedded objects to some degree. Typically, the object handling the embedded content is addressable under the Document object (as its id or name). When embedding content, it is recommended to write cross-browser scripts capable of interacting with both ActiveX controls and plug-ins.

This chapter served as an introduction to what is possible with embedded objects. A large part of ActiveX and plug-in capabilities are specific to the browser, vendor, and platform, so the best way to find information about these technologies is from the ActiveX control or plug-in vendors themselves. Because of the large number of browser bugs and documentation inconsistencies, often interaction with embedded objects is best carried out through a JavaScript library written with these subtleties in mind. Many such libraries can be found on the Web.

Embedded objects provide a way to enhance your site, not replace it. Pages should always degrade gracefully, so that they can be used by those on alternative platforms or who choose not to install plug-in, ActiveX, or Java technology. Sites that require a specific technology are very frustrating to use for the segment of the population that prefers an operating system and browser configuration other than Windows/Internet Explorer. As we discussed in the last chapter, detection techniques should always be employed to avoid locking users out of sites based upon technology limitations or client differences.