Darwin Information Typing Architecture

The Darwin Information Typing Architecture (DITA) is an XML data model for authoring and, with the DITA Open Toolkit, publishing. It is a standard^[1] that is defined and maintained by the OASIS DITA Technical Committee.^[2]

The name derives from the following components:

• Darwin: it uses the principles of specialization and inheritance, which is in some ways analogous to the naturalist Charles Darwin's concept of evolutionary adaptation,
• Information,
• Typing,
• Architecture: DITA is an extensible set of structures.^[3]

Features and limitations

Content reuse

Topics can be reused across multiple publications. Fragments of content within topics can be reused through the use of content references (conref), a transclusion mechanism.^[4]

Information typing

DITA includes three specialized topic types: Task, Concept, and Reference. Each of these three topic types is a specialization of a generic Topic type, which contains a title element, a prolog element for metadata, and a body element. The body element contains paragraph, table, and list elements, similar to HTML.

• A (General) Task topic is intended for a procedure that describes how to accomplish a task. A Task topic lists a series of steps that users follow to produce an intended outcome. The steps are contained in a taskbody element, which is a specialization of the generic body element. The steps element is a specialization of an ordered list element.
• Concept information is more objective, containing definitions, rules, and guidelines.
• A Reference topic is for topics that describe command syntax, programming instructions, and other reference material, and usually contains detailed, factual material.

Maps

A DITA map is a container for topics used to transform a collection of content into a publication. It gives the topics sequence and structure. A map can include relationship tables (reltables) that define hyperlinks between topics.^[5] Maps can be nested. Maps can reference topics or other maps, and can contain a variety of content types and metadata.

Metadata

DITA includes extensive metadata elements and attributes, both at topic level and within elements.^[6] Conditional text allows filtering or styling content based on attributes for audience, platform, product, and other properties. The conditional processing profile (.ditaval file) is used to identify which values are to be used for conditional processing.^[7]

Specialization

DITA allows adding new elements and attributes through specialization of base DITA elements and attributes. Through specialization, DITA can accommodate new topic types, element types, and attributes as needed for specific industries or companies. Specializations of DITA for specific industries, such as the semiconductor industry, are standardized through OASIS technical committees or subcommittees. Many organizations using DITA also develop their own specializations.

The extensibility of DITA permits organizations to specialize DITA by defining specific information structures and still use standard tools to work with them. The ability to define company-specific information architectures enables companies to use DITA to enrich content with metadata that is meaningful to them, and to enforce company-specific rules on document structure.^[4]

Topic orientation

DITA content is created as topics, each an individual XML file. Typically, each topic covers a specific subject with a singular intent, for example, a conceptual topic that provides an overview, or a procedural topic that explains how to accomplish a task.^[8] Content should be structured to resemble the file structure in which it is contained.^[9][10][11]

Creating content in DITA

DITA map and topic documents are XML files. As with HTML, any images, video files, or other files that must appear in the output are inserted via reference. Any XML editor or even text editor can be used to write DITA content, depending on the level of support required while authoring. Aids to authoring featured in specialized editors includes WYSIWYG preview rendering, validation, and integration with the DITA-OT. Third-party editors that support authoring DITA include Arbortext, FontoXML, FrameMaker, Oxygen XML Editor, PublishOne, Quark XML Author, SDL Xopus, and XMetaL, which are supported by several content management systems. DITA is natively supported by a number of CCMSs like Componize, DITAworks,^[12] easyDITA,^[13] IXIASOFT,^[14] and Syntext Serna.^[15]

Publishing content written in DITA

DITA is designed as an end-to-end architecture. In addition to indicating what elements, attributes, and rules are part of the DITA language, the DITA specification includes rules for publishing DITA content in HTML, online Help, print, and other formats.

For example, the DITA specification indicates that if the conref attribute of element A contains a path to element B, the contents of element B will display in the location of element A. DITA-compliant publishing solutions, known as DITA processors, must handle the conref attribute according to the specified behaviour. Rules also exist for processing other rich features such as conditional text, index markers, and topic-to-topic links. Applications that transform DITA content into other formats, and meet the DITA specification's requirements for interpreting DITA markup, are known as DITA processors.

Localization

DITA provides support for translation via the localization-atts attribute group. Element attributes can be set to indicate whether the content of the element should be translated. The language of the element content can be specified, as can the writing direction.^[16] A DITA project can be converted to an XLIFF file and back into its original maps and topics, using the DITA-XLIFF Roundtrip Tool for DITA-OT^[17][18] and computer-assisted translation (CAT) tools, like Swordfish Translation Editor.

History

• March 2001 Introduction by IBM of the core DTD and XML Schema
• May 2002 Domain specialization added to topic specialization
• April 2004 OASIS Technical Committee for DITA formed
• February 2005 SourceForge begins DITA Open Toolkit support
• June 2005 DITA v1.0 approved as an OASIS standard
• August 2005 DITA Open Toolkit v1.1 is released
• March 2006 OASIS launches DITA.XML.org
• August 2007 DITA V1.1 is approved by OASIS, including Bookmap specialization
• December 2010 DITA V1.2 is approved by OASIS, includes:
  • Indirect linking with keys
  • New content reuse features
  • Enhanced glossary support, including acronyms
  • New industry specializations (Training, Machinery)
  • New support for controlled values / taxonomies (Subject Scheme specialization)

Code samples

Ditamap file (table of contents) sample

<?xml version="1.0" encoding="utf-8" standalone="no"?>
<!DOCTYPE map PUBLIC "-//OASIS//DTD DITA Map//EN" "map.dtd">
<map id="map" xml:lang="en">
 <topicref format="dita" href="sample.dita" navtitle="Sample" type="topic"/>
</map>

Hello World (topic DTD)

<?xml version="1.0" encoding="utf-8" standalone="no"?>
<!DOCTYPE topic PUBLIC "-//OASIS//DTD DITA Topic//EN" "topic.dtd">
<topic xml:lang="en" id="sample">
 <title>Sample</title>
 <body>
 <p audience="foo">Hello World!</p>
 </body>
</topic>

.ditaval file sample (for conditionalizing text)

<?xml version="1.0" encoding="UTF-8"?>
<val>
 <prop att="audience" val="foo" action="include"/>
 <prop att="audience" val="bar" action="exclude"/>
</val>

See also

• Comparison of document markup languages
• List of document markup languages

References

External links

• DITA specification
• OASIS
• SourceForge
• DITA.XML.org