HTML and CSS Reference
In-Depth Information
12.2. Embedded Content
In this section, we cover three tags that support embedded content. The
<object>
tag is in the HTML 4 and XHTML standards. It is a generalized
hybrid of the deprecated
<applet>
tag for embedding applets, particularly
Java applets, and the
<embed>
tag extension that lets you include an ob-
ject whose Multipurpose Internet Mail Extension (MIME) type references
the plug-in needed to process and possibly display that object.
The latest standards strongly encourage you to use the
<object>
tag to
incorporate applets and other discrete inclusions in your documents, in-
cluding images (although the standards do not go so far as to deprecate
the
<img>
tag). Use
<object>
with the
classid
attribute to insert Java and
other applets into a document, along with their execution parameters as
contents of the associated
<param>
tag. Use
<object>
with the
data
attrib-
ute to download and display non-HTML/XHTML content, such as multi-
media, in the user's computing environment. Object data may be pro-
cessed and rendered by an included applet, by utilities that come with
your browser, or by a plug-in (helper) application that the user supplies.
For applets, the browser creates a display region in the containing text
flow exactly like an inline image or an
<iframe>
: without line breaks and
as a single large entity. The browser then downloads and executes the
applet's program code, if specified, and downloads and renders any in-
cluded data just after download and display of the document. Execution
of the applet continues until the code terminates itself or when the user
stops viewing the page containing the applet.
With data, the browser decodes the object's data type and either handles
its rendering directly, such as with GIF, PNG, and JPEG images, or in-
vokes an associated plug-in application for the job.
12.2.1. The <object> Tag
The
<object>
tag was originally implemented by Microsoft to support its
ActiveX controls. Only later did Microsoft add Java support. In a similar
