iPedia Free Information Center

Information about Xml Schema

This article is about XML schemas in general. For information on the W3C-recommended schema language for XML, see XML Schema (W3C).


An XML schema is a description of a type of XML document, typically expressed in terms of constraints on the structure and content of documents of that type, above and beyond the basic syntax constraints imposed by XML itself. An XML schema provides a view of the document type at a relatively high level of abstraction.

There are languages developed specifically to express XML schemas. The Document Type Definition (DTD) language, which is native to the XML specification, is a schema language that is of relatively limited capability, but that also has other uses in XML aside from the expression of schemas. Two other very popular, more expressive XML schema languages are XML Schema (W3C) and RELAX NG.

The mechanism for associating an XML document with a schema varies according to the schema language. The association may be achieved via markup within the XML document itself, or via some external means.

Validation

The process of checking to see if an XML document conforms to a schema is called validation, which is separate from XML's core concept of syntactic well-formedness. All XML documents must be well-formed, but it is not required that a document be valid unless the XML parser is "validating", in which case the document is also checked for conformance with its associated schema. DTD-validating parsers are most common, but some support W3C XML Schema or RELAX NG as well.

Documents are only considered valid if they satisfy the requirements of the schema with which they have been associated. These requirements typically include such constraints as:
  • Elements and attributes that must/may be included, and their permitted structure;
  • The structure is specified by a regular expression syntax ;
  • How character data is to be interpreted, e.g. as a number, a date, a URL, a Boolean, etc.
XML Schema validations can be effectively performed using specialized parsers, like JAXB or SAX.

XML schema languages

See also

External links

XML Schema (W3C)

File extension: .xsd
MIME type: application/xml, text/xml
Developed by: World Wide Web Consortium
Type of format: Schema language
Extended from: XML
Standard(s): 1.0, Part 1 Structures (Recommendation) ,
1.
..... Click the link for more information.
Extensible Markup Language

File extension: .xml
MIME type: application/xml, text/xml (deprecated)
Uniform Type Identifier: public.xml
Developed by: World Wide Web Consortium
Type of format: Markup language
Extended from: SGML
..... Click the link for more information.
Document Type Definition (DTD), defined slightly differently within the XML and SGML (the language XML was derived from) specifications, is one of several SGML and XML schema languages, and is also the term used to describe a document or portion thereof that is authored in
..... Click the link for more information.
XML Schema (W3C)

File extension: .xsd
MIME type: application/xml, text/xml
Developed by: World Wide Web Consortium
Type of format: Schema language
Extended from: XML
Standard(s): 1.0, Part 1 Structures (Recommendation) ,
1.
..... Click the link for more information.
In computing, RELAX NG (REgular LAnguage for XML Next Generation) is a schema language for XML, based on Murata Makoto's RELAX and James Clark's TREX. A RELAX NG schema specifies a pattern for the structure and content of an XML document.
..... Click the link for more information.
The XML Validation (eXtensible Markup Language) checks a document in XML language if it is well formed and it is adjusted to a defined structure. A well formed document follows the basic rules of XML established for the design of documents.
..... Click the link for more information.
In computing, a regular expression is a string that is used to describe or match a set of strings, according to certain syntax rules.

Regular expressions are used by many text editors, utilities, and programming languages to search and manipulate text based on patterns.
..... Click the link for more information.
number is an abstract idea used in counting and measuring. A symbol which represents a number is called a numeral, but in common usage the word number is used for both the idea and the symbol.
..... Click the link for more information.
date in a calendar is a reference to a particular day represented within a calendar system. The calendar date allows the specific day to be identified. The number of days between two dates may be calculated.
..... Click the link for more information.
Uniform Resource Locator (URL) formerly known as Universal Resource Locator, is a technical, Web-related term used in two distinct meanings:
  • In popular usage, many technical documents, it is a synonym for Uniform Resource Identifier (URI);

..... Click the link for more information.
In computer science, the Boolean datatype, sometimes called the logical datatype, is a primitive datatype having two values: one and zero (which are equivalent to true and false).
..... Click the link for more information.
Sax or sax may refer to:
  • Saxophone
  • Sax, Alicante, a municipality in Spain
  • Simple API for XML
  • a X configuration tool by SUSE Linux
  • Saxony Hotel, Miami Beach
  • Doctor Sax, a novel by Jack Kerouac

..... Click the link for more information.
Document Definition Markup Language (DDML) is an XML schema language proposed in 1999 by various contributors from the xml-dev electronic mailing list. It was published only as a W3C Note, not a Recommendation, and never found favor with developers.
..... Click the link for more information.
Document Schema Definition Languages (DSDL) is a framework within which multiple validation tasks of different types can be applied to an XML document in order to achieve more complete validation results than just the application of a single technology.
..... Click the link for more information.
Document Structure Description, or DSD, is a schema language for XML, that is, a language for describing valid XML documents. It's an alternative to DTD or the W3C XML Schema.

An example of DSD in its simplest form:

<dsd xmlns="http://www.brics.dk/DSD/2.
..... Click the link for more information.
Document Type Definition (DTD), defined slightly differently within the XML and SGML (the language XML was derived from) specifications, is one of several SGML and XML schema languages, and is also the term used to describe a document or portion thereof that is authored in
..... Click the link for more information.
In its simplest form, a Namespace Routing Language (NRL) schema consists of a mapping from namespace URIs to schema URIs. An NRL schema is written in XML.

It has been decided in December 2003 that DSDL Part 4 (ISO/IEC 19757-4) will be based on NRL.
..... Click the link for more information.
In computing, RELAX NG (REgular LAnguage for XML Next Generation) is a schema language for XML, based on Murata Makoto's RELAX and James Clark's TREX. A RELAX NG schema specifies a pattern for the structure and content of an XML document.
..... Click the link for more information.
Relax may refer to:
  • "Relax" (song) by Frankie Goes to Hollywood
  • "Relax, Take It Easy", a 2006 song by Mika
  • Relax (film), a Tamil film
  • Relax...

..... Click the link for more information.
The word Trex has the following meanings:
  • Trex a composite material.
  • Trex a card game.
  • TREX, a search engine in SAP NetWeaver.
  • Trex was a multi-user-chat bulletin board system in the San Francisco area.
  • Trex brand of cooking fat.

..... Click the link for more information.
Standard Generalized Markup Language

File extension: none
MIME type: application/sgml, text/sgml
Uniform Type Identifier: public.xml
Type of format: metalanguage
Extended from: GML
Extended to: HTML, XML
Standard(s): ISO 8879
..... Click the link for more information.
Schema for Object-Oriented XML, or SOX, is an XML schema language developed by Commerce One. In 1998 a SOX specification was submitted to the World Wide Web Consortium and published as a W3C Note. A revised version, SOX 2.0, was published as a W3C Note in 1999.
..... Click the link for more information.
highly specialized aspect of its associated subject.
Please help [ improve this article] by adding more general information.
The Schematron is an XML structure validation language for making assertions about the presence or absence of patterns in trees.
..... Click the link for more information.
XML Schema (W3C)

File extension: .xsd
MIME type: application/xml, text/xml
Developed by: World Wide Web Consortium
Type of format: Schema language
Extended from: XML
Standard(s): 1.0, Part 1 Structures (Recommendation) ,
1.
..... Click the link for more information.
data structure is a way of storing data in a computer so that it can be used efficiently. Often a carefully chosen data structure will allow the most efficient algorithm to be used. The choice of the data structure often begins from the choice of an abstract data type.
..... Click the link for more information.
Information architecture (IA) is the science of expressing a model or concept for information. Information architecture is used in library systems, web development, user interactions, database development, programming, technical writing, enterprise architecture, critical
..... Click the link for more information.
This is a list of XML schemas in use on the Internet sorted by purpose. XML schemas can be used to create XML documents for a wide range of purposes such as syndication, general exchange, and storage of data in a standard format.

Bookmarks

  • XBEL http://pyxml.sourceforge.

..... Click the link for more information.
XML Information Set (Infoset) is a W3C specification describing an abstract data model of an XML document in terms of a set of information items. The definitions in the XML Information Set specification are meant to be used in other
..... Click the link for more information.
An XML schema is a description of a type of XML document, typically expressed in terms of constraints on the structure and content of documents of that type, above and beyond the basic syntax constraints imposed by XML itself.
..... Click the link for more information.


This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.
Herod_Archelaus


page counter