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| <title>Associating Style Sheets with XML documents</title> | |
| <link rel="stylesheet" type="text/css" href="http://www.w3.org/StyleSheets/TR/W3C-REC"> | |
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| <a href="http://www.w3.org/"><img src="http://www.w3.org/Icons/WWW/w3c_home" alt="W3C" height="48" width="72"></a> | |
| <h1>Associating Style Sheets with XML documents<br>Version 1.0</h1> | |
| <h2>W3C Recommendation 29 June 1999</h2> | |
| <dl> | |
| <dt>This version:</dt> | |
| <dd> | |
| <a href="http://www.w3.org/1999/06/REC-xml-stylesheet-19990629">http://www.w3.org/1999/06/REC-xml-stylesheet-19990629</a> | |
| <br> | |
| </dd> | |
| <dt>Latest version:</dt> | |
| <dd> | |
| <a href="http://www.w3.org/TR/xml-stylesheet">http://www.w3.org/TR/xml-stylesheet</a> | |
| <br> | |
| </dd> | |
| <dt>Previous version:</dt> | |
| <dd> | |
| <a href="http://www.w3.org/TR/1999/xml-stylesheet-19990428">http://www.w3.org/TR/1999/xml-stylesheet-19990428</a> | |
| <br> | |
| </dd> | |
| <dt>Editor:</dt> | |
| <dd> | |
| James Clark | |
| <a href="mailto:jjc@jclark.com"><jjc@jclark.com></a> | |
| <br> | |
| </dd> | |
| </dl> | |
| <p class="copyright"> | |
| <a href="http://www.w3.org/Consortium/Legal/ipr-notice.html#Copyright"> | |
| Copyright</a> © 1999 <a href="http://www.w3.org">W3C</a> | |
| (<a href="http://www.lcs.mit.edu">MIT</a>, | |
| <a href="http://www.inria.fr/">INRIA</a>, | |
| <a href="http://www.keio.ac.jp/">Keio</a> ), All Rights Reserved. W3C | |
| <a href="http://www.w3.org/Consortium/Legal/ipr-notice.html#Legal Disclaimer">liability,</a><a href="http://www.w3.org/Consortium/Legal/ipr-notice.html#W3C Trademarks">trademark</a>, | |
| <a href="http://www.w3.org/Consortium/Legal/copyright-documents.html">document use </a>and | |
| <a href="http://www.w3.org/Consortium/Legal/copyright-software.html">software licensing </a>rules apply. | |
| </p> | |
| <hr title="Separator for header"> | |
| </div> | |
| <h2> | |
| <a name="abstract">Abstract</a> | |
| </h2> | |
| <p>This document allows a style sheet to be associated with an XML | |
| document by including one or more processing instructions with a | |
| target of <code>xml-stylesheet</code> in the document's prolog.</p> | |
| <h2> | |
| <a name="status">Status of this document</a> | |
| </h2> | |
| <p>This document has been reviewed by W3C Members and other interested | |
| parties and has been endorsed by the Director as a W3C <a href="http://www.w3.org/Consortium/Process/#RecsW3C">Recommendation</a>. It | |
| is a stable document and may be used as reference material or cited as | |
| a normative reference from other documents. W3C's role in making the | |
| Recommendation is to draw attention to the specification and to | |
| promote its widespread deployment. This enhances the functionality and | |
| interoperability of the Web.</p> | |
| <p>The list of known errors in this specifications is available at | |
| <a href="http://www.w3.org/1999/06/REC-xml-stylesheet-19990629/errata">http://www.w3.org/TR/1999/xml-stylesheet-19990629/errata</a>.</p> | |
| <p>Comments on this specification may be sent to <<a href="mailto:www-xml-stylesheet-comments@w3.org">www-xml-stylesheet-comments@w3.org</a>>. The archive of public | |
| comments is available at <a href="http://www.w3.org/Archives/Public/www-xml-stylesheet-comments">http://w3.org/Archives/Public/www-xml-stylesheet-comments</a>.</p> | |
| <p>A list of current W3C Recommendations and other technical documents | |
| can be found at <a href="http://www.w3.org/TR">http://www.w3.org/TR</a>.</p> | |
| <p>The Working Group expects additional mechanisms for linking style | |
| sheets to XML document to be defined in a future specification.</p> | |
| <p>The use of XML processing instructions in this specification should | |
| not be taken as a precedent. The W3C does not anticipate recommending | |
| the use of processing instructions in any future specification. The | |
| <a href="#rationale">Rationale</a> explains why they were used in | |
| this specification.</p> | |
| <p>This document was produced as part of the <a href="http://www.w3.org/XML/Activity">W3C XML Activity</a>.</p> | |
| <h2> | |
| <a name="contents">Table of contents</a> | |
| </h2>1 <a href="#The xml-stylesheet processing instruction">The xml-stylesheet processing instruction</a> | |
| <br> | |
| <h3>Appendices</h3>A <a href="#References">References</a> | |
| <br>B <a href="#rationale">Rationale</a> | |
| <br> | |
| <hr> | |
| <h2> | |
| <a name="The xml-stylesheet processing instruction"></a>1 The <code>xml-stylesheet</code> processing instruction</h2> | |
| <p>Style Sheets can be associated with an XML<a href="#XML">[XML10]</a> | |
| document by using a processing instruction whose target is | |
| <code>xml-stylesheet</code>. This processing instruction follows the | |
| behaviour of the HTML 4.0 <code><LINK | |
| REL="stylesheet"></code><a href="#HTML">[HTML40]</a>.</p> | |
| <p>The <code>xml-stylesheet</code> processing instruction is parsed in | |
| the same way as a start-tag, with the exception that entities other | |
| than predefined entities must not be referenced.</p> | |
| <p>The following grammar is given using the same notation as the | |
| grammar in the XML Recommendation<a href="#XML">[XML10]</a>. Symbols in the | |
| grammar that are not defined here are defined in the XML | |
| Recommendation.</p> | |
| <h5>xml-stylesheet processing instruction</h5> | |
| <table class="scrap"> | |
| <tbody> | |
| <tr valign="baseline"> | |
| <td> | |
| <a name="NT-StyleSheetPI"></a>[1] </td> | |
| <td>StyleSheetPI</td> | |
| <td> ::= </td> | |
| <td>'<?xml-stylesheet' (<a href="http://www.w3.org/TR/REC-xml#NT-S">S</a> <a href="#NT-PseudoAtt">PseudoAtt</a>)* <a href="http://www.w3.org/TR/REC-xml#NT-S">S</a>? '?>'</td> | |
| <td> | |
| </td> | |
| </tr> | |
| <tr valign="baseline"> | |
| <td> | |
| <a name="NT-PseudoAtt"></a>[2] </td> | |
| <td>PseudoAtt</td> | |
| <td> ::= </td> | |
| <td> | |
| <a href="http://www.w3.org/TR/REC-xml#NT-Name">Name</a> <a href="http://www.w3.org/TR/REC-xml#NT-S">S</a>? '=' <a href="http://www.w3.org/TR/REC-xml#NT-S">S</a>? <a href="#NT-PseudoAttValue">PseudoAttValue</a> | |
| </td> | |
| <td> | |
| </td> | |
| </tr> | |
| <tr valign="baseline"> | |
| <td> | |
| <a name="NT-PseudoAttValue"></a>[3] </td> | |
| <td>PseudoAttValue</td> | |
| <td> ::= </td> | |
| <td>('"' ([^"<&] | <a href="http://www.w3.org/TR/REC-xml#NT-CharRef">CharRef</a> | <a href="#NT-PredefEntityRef">PredefEntityRef</a>)* '"'</td> | |
| <td> | |
| </td> | |
| </tr> | |
| <tr valign="baseline"> | |
| <td> | |
| </td> | |
| <td> | |
| </td> | |
| <td> | |
| </td> | |
| <td>| "'" ([^'<&] | <a href="http://www.w3.org/TR/REC-xml#NT-CharRef">CharRef</a> | <a href="#NT-PredefEntityRef">PredefEntityRef</a>)* "'")</td> | |
| <td> | |
| </td> | |
| </tr> | |
| <tr valign="baseline"> | |
| <td> | |
| </td> | |
| <td> | |
| </td> | |
| <td> | |
| </td> | |
| <td>- (<a href="http://www.w3.org/TR/REC-xml#NT-Char">Char</a>* '?>' <a href="http://www.w3.org/TR/REC-xml#NT-Char">Char</a>*)</td> | |
| <td> | |
| </td> | |
| </tr> | |
| <tr valign="baseline"> | |
| <td> | |
| <a name="NT-PredefEntityRef"></a>[4] </td> | |
| <td>PredefEntityRef</td> | |
| <td> ::= </td> | |
| <td>'&amp;' | '&lt;' | '&gt;' | '&quot;' | '&apos;'</td> | |
| <td> | |
| </td> | |
| </tr> | |
| </tbody> | |
| </table> | |
| <p>In <a href="#NT-PseudoAttValue">PseudoAttValue</a>, a <a href="http://www.w3.org/TR/REC-xml#NT-CharRef">CharRef</a> or a <a href="#NT-PredefEntityRef">PredefEntityRef</a> is interpreted in the | |
| same manner as in a normal XML attribute value. The actual value of | |
| the pseudo-attribute is the value after each reference is replaced by | |
| the character it references. This replacement is not performed | |
| automatically by an XML processor.</p> | |
| <p>The <code>xml-stylesheet</code> processing instruction is allowed | |
| only in the prolog of an XML document. The syntax of XML constrains | |
| where processing instructions are allowed in the prolog; the | |
| <code>xml-stylesheet</code> processing instruction is allowed anywhere | |
| in the prolog that meets these constraints.</p> | |
| <blockquote> | |
| <b>NOTE: </b>If the <code>xml-stylesheet</code> processing instruction | |
| occurs in the external DTD subset or in a parameter entity, it is | |
| possible that it may not be processed by a non-validating XML | |
| processor (see <a href="#XML">[XML10]</a>).</blockquote> | |
| <p>The following pseudo attributes are defined</p> | |
| <pre>href CDATA #REQUIRED | |
| type CDATA #REQUIRED | |
| title CDATA #IMPLIED | |
| media CDATA #IMPLIED | |
| charset CDATA #IMPLIED | |
| alternate (yes|no) "no"</pre> | |
| <p>The semantics of the pseudo-attributes are exactly as with | |
| <code><LINK REL="stylesheet"></code> in HTML 4.0, with the | |
| exception of the <code>alternate</code> pseudo-attribute. If | |
| <code>alternate="yes"</code> is specified, then the processing | |
| instruction has the semantics of <code><LINK REL="alternate | |
| stylesheet"></code> instead of <code><LINK | |
| REL="stylesheet"></code>.</p> | |
| <blockquote> | |
| <b>NOTE: </b>Since the value of the <code>href</code> attribute is a URI | |
| reference, it may be a relative URI and it may contain a fragment | |
| identifier. In particular the URI reference may contain only a | |
| fragment identifier. Such a URI reference is a reference to a part of | |
| the document containing the <code>xml-stylesheet</code> processing | |
| instruction (see <a href="#RFC2396">[RFC2396]</a>). The consequence is that the | |
| <code>xml-stylesheet</code> processing instruction allows style sheets | |
| to be embedded in the same document as the <code>xml-stylesheet</code> | |
| processing instruction.</blockquote> | |
| <p>In some cases, style sheets may be linked with an XML document by | |
| means external to the document. For example, earlier versions of HTTP | |
| <a href="#RFC2068">[RFC2068]</a> (section 19.6.2.4) allowed style sheets to be | |
| associated with XML documents by means of the <code>Link</code> | |
| header. Any links to style sheets that are specified externally to the | |
| document are considered to occur before the links specified by the | |
| <code>xml-stylesheet</code> processing instructions. This is the same | |
| as in HTML 4.0 (see <a href="http://www.w3.org/TR/REC-html40/present/styles.html#h-14.6">section | |
| 14.6</a>).</p> | |
| <p>Here are some examples from HTML 4.0 with the corresponding | |
| processing instruction:</p> | |
| <pre><LINK href="mystyle.css" rel="style sheet" type="text/css"> | |
| <?xml-stylesheet href="mystyle.css" type="text/css"?> | |
| <LINK href="mystyle.css" title="Compact" rel="stylesheet" | |
| type="text/css"> | |
| <?xml-stylesheet href="mystyle.css" title="Compact" type="text/css"?> | |
| <LINK href="mystyle.css" title="Medium" rel="alternate stylesheet" | |
| type="text/css"> | |
| <?xml-stylesheet alternate="yes" href="mystyle.css" title="Medium" | |
| type="text/css"?></pre> | |
| <p>Multiple <code>xml-stylesheet</code> processing instructions are | |
| also allowed with exactly the same semantics as with <code>LINK | |
| REL="stylesheet"</code>. For example,</p> | |
| <pre><LINK rel="alternate stylesheet" title="compact" href="small-base.css" | |
| type="text/css"> | |
| <LINK rel="alternate stylesheet" title="compact" href="small-extras.css" | |
| type="text/css"> | |
| <LINK rel="alternate stylesheet" title="big print" href="bigprint.css" | |
| type="text/css"> | |
| <LINK rel="stylesheet" href="common.css" type="text/css"></pre> | |
| <p>would be equivalent to:</p> | |
| <pre><?xml-stylesheet alternate="yes" title="compact" href="small-base.css" | |
| type="text/css"?> | |
| <?xml-stylesheet alternate="yes" title="compact" href="small-extras.css" | |
| type="text/css"?> | |
| <?xml-stylesheet alternate="yes" title="big print" href="bigprint.css" | |
| type="text/css"?> | |
| <?xml-stylesheet href="common.css" type="text/css"?></pre> | |
| <hr title="Separator from footer"> | |
| <h2> | |
| <a name="References"></a>A References</h2> | |
| <dl> | |
| <dt> | |
| <a name="HTML">HTML40</a> | |
| </dt> | |
| <dd>World Wide Web | |
| Consortium. <i>HTML 4.0 Specification.</i> W3C Recommendation. See | |
| <a href="http://www.w3.org/TR/REC-html40">http://www.w3.org/TR/REC-html40</a> | |
| </dd> | |
| <dt> | |
| <a name="RFC2068">RFC2068</a> | |
| </dt> | |
| <dd>R. Fielding, J. Gettys, J. Mogul, | |
| H. Frystyk Nielsen, and T. Berners-Lee. <i>Hypertext Transfer | |
| Protocol -- HTTP/1.1.</i>. IETF RFC 2068. See <a href="http://www.ietf.org/rfc/rfc2068.txt">http://www.ietf.org/rfc/rfc2068.txt</a>.</dd> | |
| <dt> | |
| <a name="RFC2396">RFC2396</a> | |
| </dt> | |
| <dd>T. Berners-Lee, R. Fielding, and | |
| L. Masinter. <i>Uniform Resource Identifiers (URI): Generic | |
| Syntax</i>. IETF RFC 2396. See <a href="http://www.ietf.org/rfc/rfc2396.txt">http://www.ietf.org/rfc/rfc2396.txt</a>.</dd> | |
| <dt> | |
| <a name="XML">XML10</a> | |
| </dt> | |
| <dd>World Wide Web Consortium. <i>Extensible | |
| Markup Language (XML) 1.0.</i> W3C Recommendation. See <a href="http://www.w3.org/TR/1998/REC-xml-19980210">http://www.w3.org/TR/1998/REC-xml-19980210</a> | |
| </dd> | |
| </dl> | |
| <h2> | |
| <a name="rationale"></a>B Rationale</h2> | |
| <p>There was an urgent requirement for a specification for style sheet | |
| linking that could be completed in time for the next release from | |
| major browser vendors. Only by choosing a simple mechanism closely | |
| based on a proven existing mechanism could the specification be | |
| completed in time to meet this requirement.</p> | |
| <p>Use of a processing instruction avoids polluting the main document | |
| structure with application specific processing information.</p> | |
| <p>The mechanism chosen for this version of the specification is not a | |
| constraint on the additional mechanisms planned for future versions. | |
| There is no expectation that these will use processing instructions; | |
| indeed they may not include the linking information in the source | |
| document.</p> | |
| </body> | |
| </html> |