XPointer is a system for addressing components of XML
XML
Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
based internet media.
XPointer is divided among four specifications: a "framework
Software framework
In computer programming, a software framework is an abstraction in which software providing generic functionality can be selectively changed by user code, thus providing application specific software...
" which forms the basis for identifying XML fragments, a positional element addressing scheme, a scheme for namespaces
Namespace (computer science)
A namespace is an abstract container or environment created to hold a logical grouping of unique identifiers or symbols . An identifier defined in a namespace is associated only with that namespace. The same identifier can be independently defined in multiple namespaces...
XPath is a language for selecting nodes from an XML document. In addition, XPath may be used to compute values from the content of an XML document...
-based addressing. XPointer Framework is a recommendation since March 2003.
The XPointer language is designed to address structural aspects of XML, including text content and other information objects created as a result of parsing
Parsing
In computer science and linguistics, parsing, or, more formally, syntactic analysis, is the process of analyzing a text, made of a sequence of tokens , to determine its grammatical structure with respect to a given formal grammar...
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
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
.
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:
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))
In computer hypertext, a fragment identifier is a short string of characters that refers to a resource that is subordinate to another, primary resource...
Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
HyTime is a markup language that is an "application" of SGML. HyTime defines a set of hypertext-oriented element types that, in effect, supplement SGML and allow SGML document authors to build hypertext and multimedia presentations in a standardized way.HyTime is an international standard...
The Text Encoding Initiative is a text-centric community of practice in the academic field of digital humanities. The community runs a mailing list, meetings and conference series, and maintains a technical standard, a wiki and a toolset....
