Positioned Elements and OS Controls, Applets and Plug-ins

IFRAMEs

IFRAMEs are supported by all browsers except for NS4, which ignores the tag. IFRAME visibility persists through HTML elements except in newer versions of IE for Windows starting with IE5.5. See the first page of this article.

Type	HTML	Problem in...
IFRAME element	<IFRAME SRC="iframe.html"></IFRAME>	NS6.x Opera IE4.x IE5.0x	IE4.x IE5.x
Rendering

Active-X Controls

In IE for Windows, the term "Active-X Control" covers a great range of objects that can be included in an HTML page. Plug-ins, applets, media players, and more, are all regarded as Active-X. Again, a complete discussion is beyond our present scope. Windows, however, ships with many controls that can be included in your page. These built-in controls have no one persistence rule. Below are two examples of built-in Active-X controls, the Microsoft Form 2.0 TabStrip and the Microsoft Web Browser:

Type	HTML	Problem in...
Microsoft Form 2.0 TabStrip	<OBJECT    ID="TabStrip"    CLASSID="CLSID:EAE50EB0-4A62-11CE-BED6-00AA00611080"    WIDTH=230    HEIGHT=50>    <PARAM NAME="BackColor" VALUE="16777215">    <PARAM NAME="Items" VALUE="File;Edit;View;Favorites;Tools;Help;"> </OBJECT>	none	n/a
Renders as...
Microsoft Web Browser	<OBJECT    ID="WebBrowser"    CLASSID="CLSID:8856F961-340A-11D0-A96B-00C04FD705A2"    WIDTH=300    HEIGHT=100>    <PARAM NAME="Location" VALUE="http://www.dhtml.com/diner/seethru/browser.html"> </OBJECT>	IE4.x IE5.x IE6.x	n/a
Renders as...

Notice that one persists while the other does not. As far as built-in Active-X is concerned, therefore, it is trial and error.

What to Do?

As we have seen, there is nothing we can do.

We can, however, build our pages with this limitation in mind:

1. For example, if you are using our hierarchical menus script, ensure that the menus never appear over an applet or plug-in, by positioning them away from the menus if possible. If the menus appear from a left navigation frame, place your applets/plug-ins to the right of the main frame.
   
   
2. With form elements, consider placing the form in a positioned element that can have visibility toggled. Then "hide" the form when other positioned elements are being dragged, and "show" it only when necessary.
   
   
3. Improvise.

In a future article, we'll discuss programmable workarounds.