JavaScript and Embedded Objects

Suppose you have written some custom JavaScript to harness the capabilities provided by a specific plug-in. When users visit your page without the plug-in they are prompted to install it because you have included the proper pluginspage attribute in your <embed>. Unfortunately, if a user visits your page without the plug-in, agrees to download and install it, and then returns to your page, your JavaScript will not detect that the browser has the required plug-in. The reason is that the plugins[] array needs to be refreshed whenever a new plug-in is installed (a browser restart will work as well).

Refreshing the plugins[] array is as simple as invoking its refresh()method. Doing so causes the browser to check for newly installed plug-ins and to reflect the changes in the plugins[] and mimeTypes[]arrays. This method takes a Boolean argument indicating whether the browser should reload any current documents containing an <embed>.If you supply true, the browser causes any documents (and frames) that might be able to take advantage of the new plug-in to reload. If false is passed to the method, the plugins[] array is updated, but no documents are reloaded. A typical example of the method’s use is found here:

<em>If you have just installed the plugin, please <a href="javascript:navigator.plugins.refresh(true)">reload the page with plugin support</a></em>

Of course, this should be presented only to users of Netscape, Opera, or Mozilla-based browsers where plug-ins are supported in the first place.