XPointer

XPointer is a system for addressing components of XML based internet media.

XPointer is divided among four specifications: a "framework" which forms the basis for identifying XML fragments, a positional element addressing scheme, a scheme for namespaces, and a scheme for XPath-based addressing. XPointer Framework is a recommendation since March 2003.^[1] ^[2]

The XPointer language is designed to address structural aspects of XML, including text content and other information objects created as a result of parsing the document. Thus, it could be used to point to a section of a document highlighted by a user through a mouse drag action.

XPointer is covered by a royalty-free technology patent held by Sun Microsystems.^[3]

Positional Element Addressing

The element() scheme introduces positional addressing of child elements. This is similar to a simple XPath address, but subsequent steps can only be numbers representing the position of a descendant relative to its branch on the tree.

For instance, given the following fragment:

<foobar id="foo">
  <bar/>
  <baz>
    <bom a="1"/>
  </baz>
  <bom a="2"/>
</foobar>

results as the following examples:

 xpointer(id("foo")) => foobar
 xpointer(/foobar/1) => bar
 xpointer(//bom) => bom (a=1), bom (a=2)
 element(/1/2/1) => bom (a=1) (/1 descend into first element (foobar),
                               /2 descend into second child element (baz),
                               /1 select first child element (bom))

References

^ "XPointer Framework". Retrieved April 13, 2009.
^ "XML and Semantic Web W3C Standards Timeline" (PDF).
^ XPointer royalty-free patent statement

External links

[W3C-xptr-framework-1] "XPointer Framework". Retrieved April 13, 2009.

[timelinehistory-2] "XML and Semantic Web W3C Standards Timeline" (PDF).

[3] XPointer royalty-free patent statement

[1]

[2]

[3]

Positional Element Addressing

See also

References

External links