I am trying to use iframes as a way of re-using (transcluding) visual modules across multiple web pages. So I have one small web page for the main header and navbar, one for a side navbar and a third for the page footer. I then have a template for the rest of the pages, which invokes each of these navigation pages in a separate iframe.
Problem is, if I leave the iframe unstyled then a blank bar half an inch or more deep is added to the bottom of the transcluded page. So I get these blank bars underneath the header and footer in every page. Wastes screen space, looks bad, etc.
I can get rid of it by styling each iframe in the template with a height attribute, but that may not be robust across browsers as it ignores the actual page it contains, and will also need ny css stylesheet updating every time the navigation module changes size.