csswg-drafts/css-style-attr/Overview.src.html at dba044388c174592a6b8a17f6afa1430b6f9a219 · w3c/csswg-drafts · GitHub

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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  <title>CSS Styling Attributes Level 1</title>
  <link rel="stylesheet" type="text/css" href="default.css">

  <link rel="stylesheet" type="text/css" href="http://www.w3.org/StyleSheets/TR/W3C-ED">
</head>

<div class="head">
<!--logo-->

<h1>CSS Styling Attributes Level 1</h1>

<h2 class="no-num no-toc">[LONGSTATUS] [DATE]</h2>
<dl>
  <dt>This version:</dt>
    <dd><dd><a href="http://www.w3.org/TR/[YEAR]/WD-css-style-attr-[CDATE]/">http://www.w3.org/TR/[YEAR]/WD-css-style-attr-[CDATE]/</a></dd>
    <!-- <dd><a href="http://dev.w3.org/csswg/css-style-attr/">http://dev.w3.org/csswg/css-style-attr/</a> -->
  <dt>Latest version:
    <dd><a href="http://www.w3.org/TR/css-style-attr">http://www.w3.org/TR/css-style-attr</a>
  <dt>Previous version:
    <dd><a href="http://www.w3.org/TR/2002/WD-css-style-attr-20020515">http://www.w3.org/TR/2002/WD-css-style-attr-20020515</a>
  <dt>Editor:
    <dd><a href="http://fantasai.inkedblade.net/contact">Elika J. Etemad</a>
  <dt>Previous Editors:
  <dd><span lang="tr">Tantek &Ccedil;elik</span> (<a href="http://www.microsoft.com/">Microsoft</a>), &lt;<a href="mailto:tantekc@microsoft.com">tantekc@microsoft.com</a>&gt;
  <dd><a href="http://www.w3.org/People/Bos/">Bert Bos</a> (<a href="http://www.w3.org/">W3C</a>), &lt;<a href="mailto:bert@w3.org">bert@w3.org</a>&gt;
  <dd>Marc Attinasi (AOL/Netscape), &lt;<a href="mailto:attinasi@netscape.com">attinasi@netscape.com</a>&gt;
</dl>
<!--begin-copyright-->
<p>[Here will be included the file "../copyright.inc"]</p>
<!--end-copyright-->

<hr title="Separator for header">
</div>

<h2 class="no-num no-toc" id="abstract">Abstract</h2>

<p>Markup languages such as HTML [[HTML40]] and SVG [[SVG11]] provide a styling
attribute on most elements, to hold inline style information that applies
to those elements. One of the possible style sheet languages is CSS. This
draft describes the syntax and interpretation of the CSS fragment that can
be used in such styling attributes.

<h2 class="no-num no-toc" id="status">Status of this document</h2>
<!--status-->
  <p>This specification is a <strong>Last Call Working Draft</strong>. All
   persons are encouraged to review this document and <strong>send comments
   to the <a
   href="http://lists.w3.org/Archives/Public/www-style/">www-style</a>
   mailing list</strong> as described above. The <strong>deadline for
   comments</strong> is <strong>9 February 2010</strong>.

  <p>A CSS Styling Attribute <a href="http://www.w3.org/Style/CSS/Test/">Test
   Suite</a> will be developed during the Candidate Recommendation phase of
   this CSS Styling Attribute specification.

<h2 class="no-num no-toc" id="contents">Table of contents</h2>
<!--toc-->

<h2 id="intro">Introduction</h2>

<p>Some document formats have a <dfn>styling attribute</dfn> to permit
the author to directly apply style information to specific elements
in documents. If a document format defines a styling attribute and the
attribute accepts CSS as its value, then this specification defines that
<dfn>CSS styling attribute</dfn>&rsquo;s syntax and interpretation.

<div class="example">
  <p>The following example shows the use of the <code>style</code> attribute
  in HTML [[HTML40]]:</p>
  <pre>&lt;p style="<em>color: #090; line-height: 1.2</em>"&gt;...&lt;/p&gt;</pre>
</div>

<h2 id="conformance">Conformance</h2>

<p>A document or implementation cannot conform to CSS Styling Attributes
Level 1 alone, but can claim conformance to CSS Styling Attributes Level 1
if it satisfies the conformance requirements in this specification when
implementing CSS together with styling attribute handling as defined in a
document language that has CSS styling attributes.</p>

<p>Conformance to CSS Styling Attributes Level 1 is defined for two
classes:
<dl>
  <dt><dfn>document</dfn></dt>
    <dd>A document represented in a document language that defines a styling
      attribute for one or more of its elements.
  <dt><dfn>interpreter</dfn></dt>
    <dd>Someone or something that interprets the semantics of a document and
      its associated style information.
      (Most CSS <a href="http://www.w3.org/TR/CSS21/conform.html#user-agent">user
      agents</a> fall under this category.)</dd>
</dl>

<p>The conformance requirements are expressed with a combination of
  descriptive assertions and RFC 2119 terminology. The key words "MUST",
  "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT",
  "RECOMMENDED", "MAY", and "OPTIONAL" in the normative parts of this
  document are to be interpreted as described in RFC 2119.
  However, for readability, these words do not appear in all uppercase
  letters in this specification. All of the text of this specification is
  normative except sections explicitly marked as non-normative, examples,
  and notes. [[!RFC2119]]</p>

<p>Examples in this specification are introduced with the words "for example"
  or are set apart from the normative text with <code>class="example"</code>,
  like this:

<div class="example">
  <p>This is an example of an informative example.</p>
</div>

<p>Informative notes begin with the word "Note" and are set apart from the
  normative text with <code>class="note"</code>, like this:

<p class="note">Note, this is an informative note.</p>

<h2 id="syntax">Syntax and Parsing</h2>

<p>The value of the styling attribute must match the syntax of the contents of
a CSS <a href="http://www.w3.org/TR/CSS21/syndata.html#rule-sets">declaration
block</a>, whose formal grammar is given below in the terms and conventions of the
<a href="http://www.w3.org/TR/CSS21/syndata.html#syntax">CSS core grammar</a>:

<pre>
declaration-list
  : S* declaration? [ ';' S* declaration? ]*
  ;
</pre>

<p class="note">Note that following the CSS2.1 convention, comment tokens
are not shown in the rule above.

<p>The interpreter must parse the styling attribute's value using the
same forward-compatible parsing rules that apply to parsing declaration block
contents in a normal CSS style sheet. See
<a href="http://www.w3.org/TR/CSS21/syndata.html">chapter 4 of the CSS2.1
specification</a> for details. [[!CSS21]]

<p class="note">Note that because there is no open brace delimiting the
declaration list in the CSS styling attribute syntax, a close brace
(<code>}</code>) in the styling attribute's value does not terminate the
style data: it is merely an invalid token.</p>

<h2 id="interpret">Cascading and Interpretation</h2>

<p>The declarations in a styling attribute apply to the element to which
the attribute belongs. In the cascade, these declarations are considered
to have author origin and a specificity higher than any selector.
CSS2.1 <a href="http://www.w3.org/TR/CSS21/cascade.html#specificity">defines</a>
how style sheets and styling attributes are cascaded together. [[!CSS21]]
Relative URLs in the style data must be resolved relative to the styling
attribute's element (or to the document if per-element resolution is not
defined) when the attribute's value is parsed<!-- so dynamic changes to
the base URL don't affect the CSS ~Hixie -->.

<p>Aside from the differences in cascading, the declarations in a styling
attribute must be interpreted exactly as if they were given in a CSS
style rule that applies to the element.

<p>The CSS Working Group strongly recommends that document languages do
not allow multiple CSS styling attributes on a single element. If a document
language allows multiple CSS styling attributes, each must be parsed
independently and treated as a separate style rule, the ordering of which
should be defined by the document language, else is undefined.

<h2 id="ack">Acknowledgments</h2>

<p>Thanks to feedback from Daniel Glazman, Ian Hickson, Eric A. Meyer,
Bj&ouml;rn H&ouml;hrmann.

<h2 id="references">References

<h3 class="no-num" id="normative-references">Normative references</h3>

<!--begin-normative-->
<p>[Here will be inserted the file "normative.inc"]</p>
<!--end-normative-->

<h3 class="no-num" id="informative-references">Informative references</h3>

<!--begin-informative-->
<p>[Here will be inserted the file "informative.inc"]</p>
<!--end-informative-->

</body>
</html>
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