namespaces in xml

XML Namespaces provide a method to avoid element name conflicts.

A namespace is a collection of all the names of elements, types, and attributes in a specific schema

• In XML, element names are defined by the developer.
• This often results in a conflict when trying to mix XML documents from different XML applications.
• Namespaces let the parser know which DTD or schema you’re using so you can use the markup from several different DTDs or schemas in one document.
• Namespaces are also called vocabularies because they consist of a collection of names and definitions.

namespace xml

Namespace Declaration

When using prefixes in XML, a namespace for the prefix must be defined.

			
					<element 
      xmlns:name = "URL">

			
	

			
	
			

		
	

• With the c: prefix a qualified namespace.
• When a namespace is defined for an element, all child elements with the same prefix are associated with the same namespace.

			
					<root>
  <c:article 
      xmlns:c="https://codejagd.com/xml-namespaces">
    <c:title>XML NameSpaces</c:title>
    <c:author>CJ</c:author>
    <c:date>2022</c:date>
  </c:article>
</root>

			
	

			
	
			

		
	

namespaces xml

• The purpose of using an URI is to give the namespace a unique name.

			
					<?xml version="1.0"?>
<book 
      xmlns='urn:loc.gov:books' 
      xmlns:isbn='urn:ISBN:0-395-36341-6'>
    <title>Cheaper by the Dozen</title>
    <isbn:number>1568491379</isbn:number>
</book>

			
	

			
	
			

		
	

What is URI ?

• A Uniform Resource Identifier (URI) is a string of characters which identifies an Internet Resource.
• The most common URI is the Uniform Resource Locator (URL) which identifies an Internet domain address.

References

• XML NameSpaces