This link has been bookmarked by 74 people . It was first bookmarked on 24 Jun 2006, by mazyar hedayat.
-
29 Apr 14
-
XHTML (Extensible HyperText Markup Language) is a family of XML markup languages that mirror or extend versions of the widely used Hypertext Markup Language (HTML), the language in which Web pages are written.
While HTML (prior to HTML5) was defined as an application of Standard Generalized Markup Language (SGML), a very flexible markup language framework, XHTML is an application of XML, a more restrictive subset of SGML. Because XHTML documents need to be well-formed, they can be parsed using standard XML parsers, unlike HTML, which requires a lenient HTML-specific parser.
XHTML 1.0 became a World Wide Web Consortium (W3C) Recommendation on January 26, 2000. XHTML 1.1 became a W3C Recommendation on May 31, 2001. The standard known as XHTML5 is being developed as an XML adaptation of the HTML5 specification.
-
XHTML 1.0 is "a reformulation of the three HTML 4 document types as applications of XML 1.0".[3] The World Wide Web Consortium (W3C) also continues to maintain the HTML 4.01 Recommendation, and the specifications for HTML5 and XHTML5 are being actively developed. In the current XHTML 1.0 Recommendation document, as published and revised to August 2002, the W3C commented that, "The XHTML family is the next step in the evolution of the Internet. By migrating to XHTML today, content developers can enter the XML world with all of its attendant benefits, while still remaining confident in their content's backward and future compatibility.
-
There are various differences between XHTML and HTML. The Document Object Model is a tree structure that represents the page internally in applications, and XHTML and HTML are two different ways of representing that in markup (serializations). Both are less expressive than the DOM (for example, "--" may be placed in comments in the DOM, but cannot be represented in a comment in either XHTML or HTML), and generally XHTML's XML syntax is a little more expressive than HTML (for example, arbitrary namespaces are not allowed in HTML). First off, one source of differences is immediate: XHTML uses an XML syntax, while HTML uses a pseudo-SGML syntax (officially SGML for HTML 4 and under, but never in practice, and standardised away from SGML in HTML5). Secondly however, because the expressible contents of the DOM in syntax are slightly different, there are some changes in actual behavior between the two models
-
In the early 2000s, some Web developers began to question why Web authors ever made the leap into authoring in XHTML.[26][27][28] Others countered that the problems ascribed to the use of XHTML could mostly be attributed to two main sources: the production of invalid XHTML documents by some Web authors and the lack of support for XHTML built into Internet Explorer 6.[29][30] They went on to describe the benefits of XML-based Web documents (i.e. XHTML) regarding searching, indexing and parsing as well as future-proofing the Web itself.
-
The root element of an XHTML document must be
html, and must contain anxmlnsattribute to associate it with the XHTML namespace. The namespace URI for XHTML ishttp://www.w3.org/1999/xhtml. The example tag below additionally features anxml:langattribute to identify the document with a natural language:<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"> -
DOCTYPEs[edit]
Main article: DOCTYPEIn order to validate an XHTML document, a Document Type Declaration, or DOCTYPE, may be used. A DOCTYPE declares to the browser the Document Type Definition (DTD) to which the document conforms. A Document Type Declaration should be placed before the root element.
The system identifier part of the DOCTYPE, which in these examples is the URL that begins with http://, need only point to a copy of the DTD to use, if the validator cannot locate one based on the public identifier (the other quoted string). It does not need to be the specific URL that is in these examples; in fact, authors are encouraged to use local copies of the DTD files when possible. The public identifier, however, must be character-for-character the same as in the examples.
-
A character encoding may be specified at the beginning of an XHTML document in the XML declaration when the document is served using the
application/xhtml+xmlMIME type. (If an XML document lacks encoding specification, an XML parser assumes that the encoding is UTF-8 or UTF-16, unless the encoding has already been determined by a higher protocol.)For example:
<?xml version="1.0" encoding="UTF-8" ?>
The declaration may be optionally omitted because it declares as its encoding the default encoding. However, if the document instead makes use of XML 1.1 or another character encoding, a declaration is necessary. Internet Explorer prior to version 7 enters quirks mode, if it encounters an XML declaration in a document served as
text/html.
-
-
07 Jun 13
-
- Most prominently, behavior on parse errors differ. A fatal parse error in XML (such as an incorrect tag structure) causes document processing to be aborted.
- Most content requiring namespaces will not work in HTML, except the built-in support for SVG and MathML in the HTML5 parser along with certain magic prefixes such as
xlink. - JavaScript processing is a little different in XHTML, with minor changes in case sensitivity to some functions, and further precautions to restrict processing to well-formed content. Scripts must not use the
document.write()method; it is not available for XHTML. TheinnerHTMLproperty is available, but will not insert non-well-formed content. On the other hand, it can be used to insert well-formed namespaced content into XHTML. - CSS is also applied slightly differently. Due to XHTML's case-sensitivity, all CSS selectors become case sensitive for XHTML documents.[14] Some CSS properties, such as backgrounds, set on the
<body>element in HTML are 'inherited upwards' into the<html>element; this appears not to be the case for XHTML.[15]
-
As long as support is not widespread, most web developers avoid using XHTML that is not HTML-compatible,[23] so advantages of XML such as namespaces, faster parsing and smaller-footprint browsers do not benefit the user.
-
In October 2006, HTML inventor and W3C chair Tim Berners-Lee, introducing a major W3C effort to develop a new HTML specification, posted in his blog that, "The attempt to get the world to switch to XML … all at once didn't work. The large HTML-generating public did not move … Some large communities did shift and are enjoying the fruits of well-formed systems … The plan is to charter a completely new HTML group."[29]
-
The current HTML5 working draft says "special attention has been given to defining clear conformance criteria for user agents in an effort to improve interoperability
-
the W3C announced that it does not intend to recharter the XHTML2 WG,[49] and closed the WG in December 2010,
-
XHTML5
-
WHATWG, or Web Hypertext Application Technology Working Group
-
The key motive of the group was to create a platform for dynamic web applications;
-
they considered XHTML 2.0 to be too document-centric, and not suitable for the creation of internet forum sites or online shops.[54]
-
HTML5 has both a regular
text/htmlserialization and an XML serialization, which is known as XHTML5. In addition to the markup language, the specification includes a number of application programming interfaces. -
The Document Object Model is extended with APIs for editing, drag-and-drop, data storage and network communication.
-
-
10 Nov 12
-
<h1 id="firstHeading" class="firstHeading"><span dir="auto">XHTML</span></h1><br/> <!-- /firstHeading --><br/> <!-- bodyContent --><br/> <div id="bodyContent"><br/> <!-- tagline --><br/> <div id="siteSub">From Wikipedia, the free encyclopedia</div><br/> <!-- /tagline --><br/> <!-- subtitle --><br/> <div id="contentSub"></div><br/> <!-- /subtitle --><br/> <!-- jumpto --><br/> <div id="jump-to-nav" class="mw-jump"><br/> Jump to: <a rel="nofollow" href="#mw-head">navigation</a>, <a rel="nofollow" href="#p-search">search</a><br/> </div><br/> <!-- /jumpto --><br/> <!-- bodycontent --><br/> <div lang="en" id="mw-content-text" class="mw-content-ltr" dir="ltr"><table style="border-spacing: 3px; width:22em;" class="infobox" cellspacing="3"><br/><caption style="" class="">XHTML</caption><br/><tbody><tr class=""><br/><td style="text-align:center;" class="" colspan="2"><a rel="nofollow" href="/wiki/File:XHTML.svg" class="image"><img width="200" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/00/XHTML.svg/300px-XHTML.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/00/XHTML.svg/400px-XHTML.svg.png 2x" height="228" alt="XHTML.svg" src="//upload.wikimedia.org/wikipedia/commons/thumb/0/00/XHTML.svg/200px-XHTML.svg.png"></a></td><br/></tr><br/><tr class=""><br/><th style="text-align:left;" scope="row"><a rel="nofollow" href="/wiki/Filename_extension" title="Filename extension">Filename extension</a></th><br/><td style="" class=""><code>.xhtml, .xht,<br><br/>.xml, .html, .htm</code></td><br/></tr><br/><tr class=""><br/><th style="text-align:left;" scope="row"><a rel="nofollow" href="/wiki/Internet_media_type" title="Internet media type">Internet media type</a></th><br/><td style="" class=""><code>application/xhtml+xml</code></td><br/></tr><br/><tr class=""><br/><th style="text-align:left;" scope="row">Developed by</th><br/><td style="" class=""><a rel="nofollow" href="/wiki/World_Wide_Web_Consortium" title="World Wide Web Consortium">World Wide Web Consortium</a></td><br/></tr><br/><tr class=""><br/><th style="text-align:left;" scope="row">Initial release</th><br/><td style="" class="">26 January 2000<span style="display:none"> (<span class="bday dtstart published updated">2000-01-26</span>)</span></td><br/></tr><br/><tr class=""><br/><th style="text-align:left;" scope="row"><a rel="nofollow" href="/wiki/Software_release_life_cycle" title="Software release life cycle">Latest release</a></th><br/><td style="" class="">1.1 (Second Edition) / 23 November 2010<span class="noprint">; 23 months ago</span><span style="display:none"> (<span class="bday dtstart published updated">2010-11-23</span>)</span></td><br/></tr><br/><tr class=""><br/><th style="text-align:left;" scope="row">Type of format</th><br/><td style="" class=""><a rel="nofollow" href="/wiki/Markup_language" title="Markup language">Markup language</a></td><br/></tr><br/><tr class=""><br/><th style="text-align:left;" scope="row">Extended from</th><br/><td style="" class=""><a rel="nofollow" href="/wiki/XML" title="XML">XML</a>, <a rel="nofollow" href="/wiki/HTML" title="HTML">HTML</a></td><br/></tr><br/><tr class=""><br/><th style="text-align:left;" scope="row"><a rel="nofollow" href="/wiki/International_standard" title="International standard">Standard(s)</a></th><br/><td style="" class=""><br/><p><a rel="nofollow" href="http://www.w3.org/TR/2000/REC-xhtml1-20000126/" class="external text" rel="nofollow">1.0 (Recommendation)</a>,<br><br/><a rel="nofollow" href="http://www.w3.org/TR/2002/REC-xhtml1-20020801/" class="external text" rel="nofollow">1.0 SE (Recommendation)</a>,<br><br/><a rel="nofollow" href="http://www.w3.org/TR/2001/REC-xhtml11-20010531/" class="external text" rel="nofollow">1.1 (Recommendation)</a>,<br><br/><a rel="nofollow" href="http://www.w3.org/TR/2010/REC-xhtml11-20101123/" class="external text" rel="nofollow">1.1 SE (Recommendation)</a>,<br></p><br/><a rel="nofollow" href="http://www.w3.org/TR/html5/" class="external text" rel="nofollow">5 (Working Draft)</a></td><br/></tr><br/></tbody></table><br/><table style="float: right; clear: right; background-color: #f9f9f9; border: 1px solid #aaa; width:22em; margin: 0 0 1em 1em; padding: 0.2em; border-spacing: 0.4em 0; text-align: center; line-height: 1.4em; font-size: 88%;" class="vertical-navbox nowraplinks" cellspacing="5" cellpadding="0"><br/><tbody><tr><br/><th style="padding: 0.2em 0.4em 0.2em; font-size: 145%; line-height: 1.2em;" class=""><a rel="nofollow" href="/wiki/HTML" title="HTML">HTML</a></th><br/></tr><br/><tr><br/><td style="padding-top: 0.2em; padding-bottom: 0.2em; text-align: left;" class=""><br/><ul><br/><li><a rel="nofollow" href="/wiki/HTML" title="HTML">HTML</a> and <a rel="nofollow" href="/wiki/HTML5" title="HTML5">HTML5</a>; <a rel="nofollow" href="/wiki/HTML_editor" title="HTML editor">HTML editor</a></li><br/><li><a rel="nofollow" href="/wiki/Dynamic_HTML" title="Dynamic HTML">Dynamic HTML</a></li><br/><li><strong class="selflink">XHTML</strong><br/><ul><br/><li><a rel="nofollow" href="/wiki/XHTML_Basic" title="XHTML Basic">XHTML Basic (Mobile)</a></li><br/><li><a rel="nofollow" href="/wiki/XHTML_Mobile_Profile" title="XHTML Mobile Profile">XHTML Mobile Profile</a> and <a rel="nofollow" href="/wiki/C-HTML" title="C-HTML">C-HTML</a></li><br/></ul><br/></li><br/><li><a rel="nofollow" href="/wiki/HTML_element" title="HTML element">HTML element</a></li><br/><li><a rel="nofollow" href="/wiki/Character_encodings_in_HTML" title="Character encodings in HTML">Character encodings</a>; <a rel="nofollow" href="/wiki/Unicode_and_HTML" title="Unicode and HTML">Unicode</a></li><br/><li><a rel="nofollow" href="/wiki/Language_code" title="Language code">Language code</a></li><br/><li><a rel="nofollow" href="/wiki/Document_Object_Model" title="Document Object Model">Document Object Model</a></li><br/><li><a rel="nofollow" href="/wiki/Browser_Object_Model" title="Browser Object Model">Browser Object Model</a></li><br/><li><a rel="nofollow" href="/wiki/Style_sheet_(web_development)" title="Style sheet (web development)">Style sheets</a> and <a rel="nofollow" href="/wiki/Cascading_Style_Sheets" title="Cascading Style Sheets">CSS</a></li><br/><li><a rel="nofollow" href="/wiki/Font_family_(HTML)" title="Font family (HTML)">Font family</a> and <a rel="nofollow" href="/wiki/Web_colors" title="Web colors">Web colors</a></li><br/><li><a rel="nofollow" href="/wiki/HTML_scripting" title="HTML scripting">HTML scripting</a> and <a rel="nofollow" href="/wiki/JavaScript" title="JavaScript">JavaScript</a></li><br/><li><a rel="nofollow" href="/wiki/World_Wide_Web_Consortium" title="World Wide Web Consortium">W3C</a>, <a rel="nofollow" href="/wiki/WHATWG" title="WHATWG">WHATWG</a>, and <a rel="nofollow" href="/wiki/W3C_Markup_Validation_Service" title="W3C Markup Validation Service">validator</a></li><br/><li><a rel="nofollow" href="/wiki/Quirks_mode" title="Quirks mode">Quirks mode</a></li><br/><li><a rel="nofollow" href="/wiki/Framing_(World_Wide_Web)" title="Framing (World Wide Web)">HTML Frames</a></li><br/><li><a rel="nofollow" href="/wiki/Canvas_element" title="Canvas element">HTML5 Canvas</a>, <a rel="nofollow" href="/wiki/WebGL" title="WebGL">WebGL</a>, and <a rel="nofollow" href="/wiki/WebCL" title="WebCL">WebCL</a></li><br/><li><a rel="nofollow" href="/wiki/HTML5_Audio" title="HTML5 Audio">HTML5 Audio</a> and <a rel="nofollow" href="/wiki/HTML5_video" title="HTML5 video">HTML5 video</a></li><br/><li><a rel="nofollow" href="/wiki/Web_storage" title="Web storage">Web storage</a></li><br/><li><a rel="nofollow" href="/wiki/Web_browser_engine" title="Web browser engine">Web browser (layout) engine</a></li><br/><li>Comparison of<br/><ul><br/><li><a rel="nofollow" href="/wiki/Comparison_of_document_markup_languages" title="Comparison of document markup languages">document markup languages</a></li><br/><li><a rel="nofollow" href="/wiki/Comparison_of_web_browsers" title="Comparison of web browsers">web browsers</a></li><br/><li><a rel="nofollow" href="/wiki/Comparison_of_web_browser_engines" title="Comparison of web browser engines">layout engine support</a> for<br/><ul><br/><li><a rel="nofollow" href="/wiki/Comparison_of_layout_engines_(HTML)" title="Comparison of layout engines (HTML)">HTML</a>; <a rel="nofollow" href="/wiki/Comparison_of_layout_engines_(non-standard_HTML)" title="Comparison of layout engines (non-standard HTML)">Non-standard HTML</a></li><br/><li><a rel="nofollow" href="/wiki/Comparison_of_layout_engines_(XHTML)" title="Comparison of layout engines (XHTML)">XHTML</a> (<a rel="nofollow" href="/wiki/Comparison_of_layout_engines_(XHTML_1.1)" title="Comparison of layout engines (XHTML 1.1)">1.1</a>)</li><br/><li><a rel="nofollow" href="/wiki/Comparison_of_layout_engines_(HTML5)" title="Comparison of layout engines (HTML5)">HTML5</a>; <a rel="nofollow" href="/wiki/Comparison_of_layout_engines_(HTML5_canvas)" title="Comparison of layout engines (HTML5 canvas)">HTML5 canvas</a>,<br/><ul><br/><li><a rel="nofollow" href="/wiki/Comparison_of_layout_engines_(HTML5_media)" title="Comparison of layout engines (HTML5 media)">HTML5 media (Audio, Video)</a></li><br/></ul><br/></li><br/></ul><br/></li><br/></ul><br/></li><br/></ul><br/></td><br/></tr><br/><tr><br/><td style="text-align: right; font-size: 115%;"><br/><div style="" class="noprint plainlinks hlist navbar mini"><br/><ul><br/><li class="nv-view"><a rel="nofollow" href="/wiki/Template:HTML" title="Template:HTML"><span style="" title="View this template">v</span></a></li><br/><li class="nv-talk"><a rel="nofollow" href="/wiki/Template_talk:HTML" title="Template talk:HTML"><span style="" title="Discuss this template">t</span></a></li><br/><li class="nv-edit"><a rel="nofollow" href="//en.wikipedia.org/w/index.php?title=Template:HTML&action=edit" class="external text"><span style="" title="Edit this template">e</span></a></li><br/></ul><br/></div><br/></td><br/></tr><br/></tbody></table><br/><p><b>XHTML (E<u>x</u>tensible <u>H</u>yper<u>T</u>ext <u>M</u>arkup <u>L</u>anguage)</b> is a family of <a rel="nofollow" href="/wiki/XML" title="XML">XML</a> <a rel="nofollow" href="/wiki/Markup_language" title="Markup language">markup languages</a> that mirror or extend versions of the widely used <a rel="nofollow" href="/wiki/Hypertext_Markup_Language" class="mw-redirect" title="Hypertext Markup Language">Hypertext Markup Language</a> (HTML), the language in which <a rel="nofollow" href="/wiki/Web_page" title="Web page">web pages</a> are written.</p><br/><p>While HTML (prior to <a rel="nofollow" href="/wiki/HTML5" title="HTML5">HTML5</a>) was defined as an application of <a rel="nofollow" href="/wiki/Standard_Generalized_Markup_Language" title="Standard Generalized Markup Language">Standard Generalized Markup Language</a> (SGML), a very flexible markup lang</p></div></div>
-
age framework, XHTML is an application of XML, a more restrictive subset of SGML. Because XHTML documents need to be well-formed, they can be parsed using standard XML parsers—unlike HTML, which requires a lenient HTML-specific parser.
XHTML 1.0 became a World Wide Web Consortium (W3C) Recommendation on January 26, 2000. XHTML 1.1 became a W3C Recommendation on May 31, 2001. XHTML5 is undergoing development as of September 2009, as part of the HTML5 specification.
-
- Broadly, the XML rules require that all elements be closed, either by a separate closing tag or using self-closing syntax (e.g.
<br />), while HTML syntax permits some elements to be unclosed because either they are always empty (e.g.<input>) or their end can be determined implicitly ("omissibility", e.g.<p>). - XML is case-sensitive for element and
Relationship to HTML
There are various differences between XHTML and HTML. The Document Object Model is a tree structure that represents the page internally in applications, and XHTML and HTML are two different ways of representing that in markup (serializations). Both are less expressive than the DOM (for example, "--" may be placed in comments in the DOM, but cannot be represented in a comment in either XHTML or HTML), and generally XHTML's XML syntax is a little more expressive than HTML (for example, arbitrary namespaces are not allowed in HTML). So, firstly one source of differences is immediate: XHTML uses an XML syntax, while HTML uses a pseudo-SGML syntax (officially SGML for HTML 4 and under, but never in practice, and standardised away from SGML in HTML5). Secondly however, because the expressible contents of the DOM in syntax are slightly different, there are some changes in actual behavior between the two models.
First, there are some differences in syntax:[12]
- Broadly, the XML rules require that all elements be closed, either by a separate closing tag or using self-closing syntax (e.g.
-
- attribute names, while HTML is not.
- Some shorthand features in HTML are omitted in XML, such as (1) attribute minimization, where attribute values or their quotes may be omitted (e.g.
<option selected>or<option selected=selected>, while XML this must be expressed as<option selected="selected">); (2) element minimization may be used to remove elements entirely (such as<tbody>inferred in a table if not given); and (3) the rarely used SGML syntax for element minimization ("shorttag"), which most browsers do not implement.[13] - There are numerous other technical requirements surrounding namespaces and precise parsing of whitespace and certain characters and elements. The exact parsing of HTML in practice has been undefined until recently; see the HTML5 specification ([HTML5]) for full details, or the working summary (HTML vs. XHTML).
Secondly, in contrast to these minor syntactical differences, there are some behavioral differences, mostly
-
- Most prominently, behavior on parse errors differ. A fatal parse error in XML (such as an incorrect tag structure) causes document processing to be aborted.
- Most content requiring namespaces will not work in HTML, except the built-in support for SVG and MathML in the HTML5 parser along with certain magic prefixes such as
xlink.
arising from the underlying differences in serialization. For example:
-
- JavaScript processing is a little different in XHTML, with minor changes in case sensitivity to some functions, and further precautions to restrict processing to well-formed content. Scripts must not use the
document.write()method; it is not available for XHTML. TheinnerHTMLproperty is available, but will not insert non-well-formed content. On the other hand, it can be used to insert well-formed namespaced content into XHTML. - CSS is also applied slightly differently. Due to XHTML's case-sensitivity, all CSS selectors become case sensitive for XHTML documents.[14] Some CSS properties, such as backgrounds, set on the
<body>element in HTML are 'inherited upwards' into the<html>element; this appears not to be the case for XHTML.[15]
[edit] Adoption
- JavaScript processing is a little different in XHTML, with minor changes in case sensitivity to some functions, and further precautions to restrict processing to well-formed content. Scripts must not use the
-
-
18 Jul 12
-
namespaces are not allowed in HTML
-
Most content requiring namespaces will not work in HTML, except the built-in support for SVG and MathML in the HTML5 parser along with certain magic prefixes such as
xlink.
-
-
01 Jun 12
-
XHTML uses an XML syntax, while HTML uses a pseudo-SGML syntax
-
-
12 Aug 11
-
XHTML was developed to make HTML more extensible and increase interoperability with other data formats
-
By shifting to an XML format, it was hoped HTML would become compatible with common XML tools
-
servers and proxies would be able to transform content, as necessary, for constrained devices such as mobile phones.
-
XHTML and HTML are two different ways of representing that in markup
-
XHTML's XML syntax is a little more expressive than HTML
-
XHTML uses an XML syntax, while HTML uses a pseudo-SGML syntax
-
the XML rules require that all elements be closed,
-
XML is case-sensitive for element and attribute names, while HTML is not.
-
Some shorthand features in HTML are omitted in XML,
-
causes document processing to be aborted
-
behaviour on parse errors differ. A fatal parse error in XML
-
document.write()method, which is not available in XHTML pages so the scripts fail on pages served as XHTML -
The
innerHTMLproperty is available on XML pages
-
-
26 May 11
-
19 Apr 11
-
10 Apr 11
-
mirror or extend versions of the widely-used Hypertext Markup Language (HTML)
-
n application of Standard Generalized Markup Language (SGML)
-
HTML documents need to be well-formed
-
an application of XML, a more restrictive subset of SGML
-
-
13 Sep 10
Dante-Gabryell MonsonBecause XHTML documents need to be well-formed, they can be parsed using standard XML parsers
-
02 Apr 10
Max Limitz"XHTML (Extensible Hypertext Markup Language) is a family of XML markup languages that mirror or extend versions of the widely used Hypertext Markup Language (HTML), the language in which web pages are written. While HTML (prior to HTML5) was defined as a
-
12 Mar 10
Chris inCaXHTML (Extensible Hypertext Markup Language) is a family of XML markup languages that mirror or extend versions of the widely used Hypertext Markup Language (HTML), the language in which web pages are written.
-
17 Feb 10
-
09 Feb 10
-
18 Jan 10
-
05 Dec 09
-
23 Oct 09
-
07 Apr 09
Thành BùiXHTML Basic and XHTML-MP
-
09 Feb 09
-
XHTML
-
XHTML
-
-
25 Sep 08
-
17 Aug 08
-
29 Jul 08
-
Because they need to be well-formed, true XHTML documents allow for automated processing to be performed using standard XML tools
-
The Extensible Hypertext Markup Language, or XHTML, is a markup language that has the same depth of expression as HTML, but also conforms to XML syntax
-
true XHTML documents allow for automated processing to be performed using standard XML tools—unlike HTML, which requires a relatively complex, lenient, and generally custom parser. XHTML can be thought of as the intersection of HTML and XML in many respects, since it is a reformulation of HTML in XML
-
The need for a reformulated version of HTML was felt primarily because World Wide Web content now needs to be delivered to many devices (like mobile devices) apart from traditional desktop computers, where extra resources cannot be devoted to support the additional complexity of HTML syntax.[citation needed] In practice, however, HTML-supporting browsers for such constrained devices have emerged faster than XHTML support has been added to the desktop browser
-
Another goal for XHTML and XML was to reduce the demands on parsers and user agents in general.
-
With HTML, user agents increasingly took on the burden of "correcting" errant documents. Instead, XML requires user agents to give a "fatal" error when encountering malformed XML. In theory, this allows for vendors to produce leaner browsers, without the obligation to work around author errors. A side effect of this behavior is that those authoring XHTML documents and testing in conformant browsers should be more readily alerted to errors that may have gone otherwise unnoticed if the browser had attempted to render or ignore the malformed markup.
-
A feature XHTML inherits from its XML underpinnings is XML namespaces.[citation needed] With namespaces, authors or communities of authors can define their own XML elements, attributes and content models to mix within XHTML documents.
-
The changes from HTML to first-generation XHTML 1.0 are minor and are mainly to achieve conformance with XML. The most important change is the requirement that the document must be well-formed and that all elements must be explicitly closed as required in XML.
-
-
11 Mar 08
-
01 Mar 08
-
26 Jan 08
-
31 Dec 07
-
17 Oct 07
-
12 Jul 07
-
27 Mar 07
Mark pearsonUseful overview of the genesis of XHTML. XHTML 2.0 draft specification is very inteesting.
Of particular value is the Common errors section which outlines where the specification differs radically from HTML 4.01 and gives egs of mistakes. -
14 Feb 07
-
26 Nov 06
avivajazz jazzavivaThe Extensible HyperText Markup Language, or XHTML, is a markup language that has the same expressive possibilities as HTML, but a stricter, more verbose syntax. Whereas HTML is an application of SGML, a very flexible markup language, XHTML is an applicat
-
07 Nov 06
-
07 Aug 06
-
02 Mar 06
Would you like to comment?
Join Diigo for a free account, or sign in if you are already a member.