Almost three years of work of the OASIS DITA Technical Committee has
gone into the development of version 1.2 of the DITA standard. DITA 1.2
introduces a number of innovations that open the door to powerful new features
in authoring and publishing tools. Amongst the new 1.2 features are keyref
(allowing link targets to be specific to the ditamap), extensions to the way in
which content references (conref) can be used, glossary and terminology
processing, new learning information types, and constrained information types
to simplify the authoring learning curve.
The improvements in DITA 1.2 will make new functionality possible, but
it will be up to authoring and publishing tool vendors to take advantage of the
new standard. Some functionality improvements will arise out of new features,
while others are made possible by changes to existing features.
Indirection and the Keyref Feature
Cross-references and other forms of links are quite simple: the link
references the location of the target of the link. However, there are cases
where the target of the link within a topic will be different depending on the
document or publication in which the topic is used. DITA 1.2 introduces
indirect linking, where a link in a topic only references a key, and the target
of the link is defined in a keys section within the ditamap. In this way, the
target of a link can be defined in the ditamap (at the document level) rather
than in the topic.
For example, a link in a topic may reference a key named "local_law".
When the topic is used in a ditamap for the German market, the "local_law" key
could be specified in the ditamap to reference a German government Web site.
When the same topic is used in a different ditamap for the Austrian market, the
key in that ditamap could reference an Austrian government site.
Changes to the Way Conref Works
The content reference (conref) mechanism in DITA is the main enabler
of content re-use. An element of nearly any type can be re-used, or
"transcluded", from its source location to another location. DITA 1.2 has
extended the possibilities for transclusion by allowing a group of sibling
elements (such as a group of steps) to be re-used in one simple process. This
change has been implemented by the addition of a conrefend attribute, which
specifies the id of the last sibling element in the group to be transcluded.
Another interesting addition in DITA 1.2 is "conref push", where
information in one topic can be inserted in another, without the target topic
having to be modified at all. For example, a wholesaler may produce topics that
are regularly updated and provided to retailers. A retailer wanting to use the
topics in their own publication might choose to "push" some customised content
into the wholesaler's topics without actually editing them.
Glossary and Terminology Management and Processing
At the heart of the new terminology management features in DITA 1.2 is
a new information type of glossentry. Glossary terms and their definitions are
defined individually in simple, glossentry topics with rich semantics. As well
as the term and definition, the author can define short forms of the term,
synonyms, alternative forms, and even parts of speech. The glossary entry
topics can be collected together in a ditamap using a new glossref alternative
to the standard topicref element.
A new keyref attribute in the term element will make it possible for
terms in within the body text of topics to be automatically linked to the
corresponding glossary definition during the publishing process.
Learning Specialisation Information Types
One of the interesting new developments is that some specialised
information types designed by subcommittees of the DITA Technical Committee are
being incorporated into the base DITA standard. The new Learning
specialisations, devised by the Learning and Training Subcommittee, provide
information structures to suit training materials. Topic types such as
learningPlan, learningOverview, LearningContent, learningSummary, and
learningAssessment, make it easier to produce learning objects. New elements
for interaction semantics, such as those for true/false, multiple choice, and
sequencing questions, make it easy to use DITA as assessment content.
The General Task Information Type
One of the criticisms of DITA's content model has been that it does
not specifically provide for upper level processes, or informal procedures.
That issue has been addressed by the addition of a general task information
type, which is much less strict than the task information type (which is now
referred to as "strict task").
There are a number of other changes in
DITA 1.2 that are aim to further improve the usefulness of DITA. These include:
- subject schemes, where
lists of acceptable values for attributes can be defined;
- changes to structure of
the schema and DTD files to make it easier to specialise;
- the "constraints"
mechanism, which allows restrictions to be applied to information types to make
the author's life easier by having fewer choices of elements;
- new sectiondiv and bodydiv
elements, to make it easier to apply metadata to multiple elements at the one
Although it has been a very long time coming, the improvements
embodied in DITA 1.2 make an even stronger case for migration to DITA. As
software vendors embrace the opportunities to add greater functionality to
their products, DITA authors will enjoy a richer authoring environment, and
readers will benefit from better information products.