Difference between revisions of "class-design-pattern"

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(Referenced naming principles)
(update with references to semantic-xhtml and class-names pages, add more detail to steps, and reorder/collapse)
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= Class design pattern =
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<h1> Class design pattern </h1>
  
 
== Purpose ==
 
== Purpose ==
Use the [[class-design-pattern]] to indicate semantic meaning about XHTML elements
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Use the [[class-design-pattern]] to indicate semantic meaning about XHTML elements.  See the discussion of [[semantic-class-names]] for background.
  
 
== How to use it ==
 
== How to use it ==
* add semantics to (X)HTML by using [http://www.w3.org/TR/REC-html40/struct/global.html#adef-class class names].  The <code>class</code> attribute is a space sepearted list of class names.
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* always use the most appropriately [[semantic-xhtml|semantic (X)HTML]] element for the content. if an appropriate semantic element is not available, use <code>span</code> or <code>div</code>. always avoid [[presentational-xhtml|presentational (X)HTML]].
* if an appropriate semantic element is not available, use <code>span</code> or <code>div</code>.
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* add semantics to (X)HTML by using [[semantic-class-names]].  The <code>class</code> attribute is a space separated list of class names.
 
* always choose names following the [[naming-principles|microformats naming principles]].
 
* always choose names following the [[naming-principles|microformats naming principles]].
  
 
== Description ==
 
== Description ==
  
This is one of the most frequently occurring design patterns in microformats. Semantic meaning can be indicated on XHTML content by using the <code>class</code> attribute of an enclosing element. For example, [[hcard]] adds information indicating that certain elements are a vCard URL, a Full Name and Organization by the class design pattern:
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This is one of the most frequently occurring design patterns in microformats. Semantic meaning can be indicated on XHTML content by using the <code>class</code> attribute of an enclosing element. For example, [[hcard|hCard]] adds information indicating that certain elements represent vCard person or organization, its URL, Formatted Name, and Organization by the class design pattern:
  
 
<pre><nowiki>
 
<pre><nowiki>
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</nowiki></pre>
 
</nowiki></pre>
  
Note especially the preceding example:
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Note in particular:
  
 
* the section of the XHTML document that the microformat is being applied to is defined by <code>class="vcard"</code>. This is very common among non-trivial microformats.
 
* the section of the XHTML document that the microformat is being applied to is defined by <code>class="vcard"</code>. This is very common among non-trivial microformats.
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** single elements to have multiple meanings
 
** single elements to have multiple meanings
 
** allows adding semantics to existing presentation
 
** allows adding semantics to existing presentation
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== Related ==
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* [[semantic-xhtml]]
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* [[semantic-class-names]]
  
 
== See Also ==
 
== See Also ==
 
* [[Main_Page#Design_Patterns|All microformat design patterns]]
 
* [[Main_Page#Design_Patterns|All microformat design patterns]]
 
* John Udell [http://weblog.infoworld.com/udell/2004/02/09.html writes] about multiple class names
 
* John Udell [http://weblog.infoworld.com/udell/2004/02/09.html writes] about multiple class names
* [http://www.w3.org/TR/REC-html40/struct/global.html#adef-class HTML 4.0 defintion of 'class'], including notes about multiple class names
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* [http://www.w3.org/TR/html401/struct/global.html#adef-class HTML 4.01 definition of the 'class' attribute], including notes about multiple class names

Revision as of 19:00, 29 January 2007

Class design pattern

Purpose

Use the class-design-pattern to indicate semantic meaning about XHTML elements. See the discussion of semantic class names for background.

How to use it

Description

This is one of the most frequently occurring design patterns in microformats. Semantic meaning can be indicated on XHTML content by using the class attribute of an enclosing element. For example, hCard adds information indicating that certain elements represent vCard person or organization, its URL, Formatted Name, and Organization by the class design pattern:

<div class="vcard">
 <a class="url fn" href="http://tantek.com/">Tantek Çelik</a>,
 <span class="org">Technorati</span>
</div>

Note in particular:

  • the section of the XHTML document that the microformat is being applied to is defined by class="vcard". This is very common among non-trivial microformats.
  • the use of both inline (<a> and <span>) and block (<div>) level elements. This provides the microformat designer with a range of options for inserting semantic information without interfering with existing presentation
  • the use of multiple class names on a single element (such as "url fn"). This allows:
    • single elements to have multiple meanings
    • allows adding semantics to existing presentation

Related

See Also