HTML and CSS Reference
In-Depth Information
browser can determine the object type from the object's URL or server.
You must supply a
type
attribute if you don't include the
src
attribute.
It may seem odd to use an
<embed>
tag without an
src
attribute reference
to some object, but this is common if the plug-in requires no data or
retrieves its data dynamically after it is started. In these cases, the
type
attribute is required so that the browser knows which plug-in to invoke.
12.2.4.8. The units attribute
Pixels are the default unit of measure for the
height
and
width
attributes
that control the
<embed>
display space. The
units
attribute lets you expli-
citly state that the absolute measure is
pixels
, or change it to the relat-
ive
en
, which is one-half the current point size of text in the document.
With the
en
units, you tailor the object's viewing area (
viewport
) to be
proportional to its immediately surrounding content, the size of which is
varied by the user.
For example, this tag creates a viewport of 200 x 320 pixels:
<embed src=movie.avi height=200 width=320 units=pixels>
By changing
units
to
en
, that same viewport, when included within a
flow of 12-point text, becomes 1200 x 1920 pixels.
12.2.5. The <noembed> Tag (Extension)
The
<noembed>
tag, although not part of the standards, is supported by
the popular browsers; they consequently ignore the
<noembed>
enclosed
text. On the other hand, browsers that do not recognize
<embed>
ignore
<noembed>
, too, consequently displaying the latter tag's enclosed text
and thereby supplying alternative content to tell users what they are
missing in the
<embed>
content.