XML namespace: Difference between revisions

Revision as of 22:00, 20 March 2008

Revision as of 17:55, 17 April 2008

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== Namespace declaration ==

A namespace is declared using the reserved XML attribute <code>xmlns</code>, the value of which must be a [[Uniform Resource Identifier|URI]] (Uniform Resource IdentifierURI) reference.

For example:

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<pre><nowiki>xmlns="http://www.w3.org/1999/xhtml"</nowiki></pre>

Note, however, that the URI is not actually read as an online address; it is simply treated by an XML parser as a string. For example, the pagedocument at [http://www.w3.org/1999/xhtml http://www.w3.org/1999/xhtml] itself does not contain any code,. itIt simply describes the [[xhtmlXHTML]] namespace to human readers. Using a URLURI (such as <nowiki>"http://www.w3.org/1999/xhtml"</nowiki>) to identify a namespace, rather than a simple string (such as "xhtml"), reduces the possibility of different namespaces using duplicate identifiers.

It is also possible to map namespaces to prefixes in namespace declarations. For example: