Information Technology Reference
In-Depth Information
14
Figure 14.1
The Document Object Model (DOM)
<html>
<head>
<body>
<title>
<h1>
<a_>
Tex t
Heading…
href“”…
Rendering Engines
A rendering (or layout) engine like Gecko is the power under the hood of a Web browser. A browser
provides the toolbars and menus that allow you to see web content in a familiar context, similar to
other desktop applications. A layout engine translates all those HTML tags, image files, cascading
style sheets and video links into what we think of as a web page.
Layout engines can be used in any application that displays HTML graphically. Gecko is the engine
behind all the Mozilla products; not just Firefox, but the Seamonkey browser suite and
Thunderbird email client as well.
Other prominent layout engines include: Trident (used in Microsoft Internet Explorer and some ver-
sions of Outlook), WebKit (used in Apple Safari and Google Chrome), and Presto (used in the
Opera browser).
Writing HTML-Friendly XHTML in WordPress
We described in Chapter 6 some of the ways that the WordPress visual editor takes care of most of
the XHTML-specific issues without you having to think about it. Besides handling the proper tag-
ging of italic and bold text, the editor covers some of the housekeeping functions of a well-formed
XHTML page:
•
Declaring a DOCTYPE and namespace in the page header
•
Making sure all tags are closed out with the
</tag>
•
Using lowercase for tags
•
Putting quotes around link URLs and other tag attributes
