Contents
This section is normative.
This module defines all of the basic text container elements, attributes, and their content models that are structural in nature.
Element | Attributes | Content Model |
---|---|---|
address | Common | (PCDATA | Text)* |
blockcode | Common | (PCDATA | Text | Heading | Structural | List)* |
blockquote | Common | (PCDATA | Text | Heading | Structural | List)* |
div | Common | (PCDATA | Flow)* |
h | Common | (PCDATA | Text)* |
h1 | Common | (PCDATA | Text)* |
h2 | Common | (PCDATA | Text)* |
h3 | Common | (PCDATA | Text)* |
h4 | Common | (PCDATA | Text)* |
h5 | Common | (PCDATA | Text)* |
h6 | Common | (PCDATA | Text)* |
p | Common | (PCDATA | Text | List | blockcode | blockquote | pre | table )* |
pre | Common | (PCDATA | Text)* |
section | Common | (PCDATA | Flow)* |
separator | Common | EMPTY |
The content model for this module defines some content sets:
Implementation: RELAX NG
The address element may be used by authors to supply contact information for a document or a major part of a document such as a form.
Attributes
Example
<address href="mailto:webmaster@example.net">Webmaster</address>
This element indicates that its contents are a block of "code" (see the code element). This element is similar to the pre element, in that whitespace in the enclosed text has semantic relevance. As a result, the default value of the layout attribute is relevant.
Attributes
Example of a code fragment:
<blockcode class="Perl"> sub squareFn { my $var = shift; return $var * $var ; } </blockcode>
Here is how this might be rendered:
sub squareFn {
my $var = shift;
return $var * $var ;
}
This element designates a block of quoted text.
Attributes
An excerpt from 'The Two Towers', by J.R.R. Tolkien, as a blockquote
<blockquote cite="http://www.example.com/tolkien/twotowers.html"> <p>They went in single file, running like hounds on a strong scent, and an eager light was in their eyes. Nearly due west the broad swath of the marching Orcs tramped its ugly slot; the sweet grass of Rohan had been bruised and blackened as they passed.</p> </blockquote>
The div element, in conjunction with the id, class and role attributes, offers a generic mechanism for adding extra structure to documents. This element defines no presentational idioms on the content. Thus, authors may use this element in conjunction with style sheets, the xml:lang attribute, etc., to tailor XHTML to their own needs and tastes.
Attributes
For example, suppose you wish to make a presentation in XHTML, where each slide is enclosed in a separate element. You could use a
div element, with a
class of slide
:
div with a class of slide
<body> <h>The meaning of life</h> <p>By Huntington B. Snark</p> <div class="slide"> <h>What do I mean by "life"</h> <p>....</p> </div> <div class="slide"> <h>What do I mean by "mean"?</h> ... </div> ... </body>
A heading element briefly describes the topic of the section it introduces. Heading information may be used by user agents, for example, to construct a table of contents for a document automatically.
Attributes
There are two styles of headings in XHTML: the numbered versions h1, h2 etc., and the structured version h, which is used in combination with the section element.
There are six levels of numbered headings in XHTML with h1 as the most important and h6 as the least.
Structured headings use the single h element, in combination with the section element to indicate the structure of the document, and the nesting of the sections indicates the importance of the heading. The heading for the section is the one that is a child of the section element.
Example
<body> <h>This is a top level heading</h> <p>....</p> <section> <p>....</p> <h>This is a second-level heading</h> <p>....</p> <h>This is another second-level heading</h> <p>....</p> </section> <section> <p>....</p> <h>This is another second-level heading</h> <p>....</p> <section> <h>This is a third-level heading</h> <p>....</p> </section> </section> </body>
Sample style sheet for section levels
h {font-family: sans-serif; font-weight: bold; font-size: 200%} section h {font-size: 150%} /* A second-level heading */ section section h {font-size: 120%} /* A third-level heading */
Numbered sections and references
XHTML does not itself cause section numbers to be generated from headings. Style sheet languages such as CSS however allow authors to control the generation of section numbers.
The practice of skipping heading levels is considered to be bad practice. The series h1 h2 h1 is acceptable, while h1 h3 h1 is not, since the heading level h2 has been skipped.
The p element represents a paragraph.
In comparison with earlier versions of HTML, where a paragraph could only contain inline text, XHTML2's paragraphs represent the conceptual idea of a paragraph, and so may contain lists, blockquotes, pre's and tables as well as inline text. Note however that they may not contain directly nested p elements.
Attributes
Example
<p>Payment options include: <ul> <li>cash</li> <li>credit card</li> <li>luncheon vouchers.</li> </ul> </p>
The pre element indicates that whitespace in the enclosed text has semantic relevance. As such, the default value of the layout attribute is relevant.
Note that all elements in the XHTML family preserve their whitespace in the document, which is only removed on rendering, via a style sheet, according to the rules of CSS [CSS3-TEXT]. This means that in principle any elements may preserve or collapse whitespace on rendering, under control of a style sheet.
Attributes
A bad poem where whitespace matters
<pre> If I had any talent I would be a poet </pre>
Here is how this might be rendered:
If I had any talent I would be a poet
Note that while historically one use of the pre element has been as a container for source code, the blockcode element is intended for that.
The section element, in conjunction with the h element, offers a mechanism for structuring documents into sections. This element defines content to be block-level but imposes no other presentational idioms on the content, which may otherwise be controlled from a style sheet.
Attributes
By representing the structure of documents explicitly using the section and h elements gives the author greater control over presentation possibilities than the traditional implicit structuring using numbered levels of headings. For instance, it is then possible to indicate the nesting of sections by causing a border to be displayed to the left of sections.
Example
<body> <h>Events</h> <section> <h>Introduction</h> <p>....</p> <h>Specifying events</h> <p>...</p> <section> <h>Attaching events to the handler</h> <p>...</p> </section> <section> <h>Attaching events to the listener</h> <p>...</p> </section> <section> <h>Specifying the binding elsewhere</h> <p>...</p> </section> </section> </body>
The separator element separates parts of the document from each other.
Attributes
Example
<p>This is some lead in text</p> <separator /> <p>This is some additional, but separate text.</p>
Example
<nl> <label>Navigation</label> <li href="/">Home</li> <li><separator/></li> <li href="prev">Previous</li> <li href="..">Up</li> <li href="next">Next</li> </nl>
[XHTML2] How are UAs to interpret <h> and <hx> elements?
PR #7820
State: Open
Resolution: None
User: None
Notes:
[XHTML2] How are UAs to interpret <h> and <hx> elements?
PR #7830
State: Open
Resolution: None
User: None
Notes:
block@kind vs elt@structure
PR #7874
State: Open
Resolution: None
User: None
Notes:
redundant content model
PR #7875
State: Open
Resolution: None
User: None
Notes:
Agreed - should change these to be Flow.
headings -- numbered vs bare
PR #7877
State: Open
Resolution: None
User: None
Notes:
You are correct - there is nothing but good taste to prevent people doing silly
things. However, we need better wording to clarify that the content model does
indeed support bad taste.
What is the scope of a header?
PR #7878
State: Approved
Resolution: Accepted
User: None
Notes:
Group agrees that the scope needs a better explanation.