Overview of the approach

Specialization by example makes use of design examples, a representation of the DITA model, and a method for producing artifacts for standard XML infrastructure from the model representation.

The essential characteristics of the approach are as follows:

• A method similar to Examplotron to define a specialization module by annotating an example of the base module with design attributes, leveraging the base design as much as possible.
• A method similar to ODD for representing the DITA model with a specialized map that establishes relationships over reference topics.

  The representation uses a specialized DITA map rather than a specialized DITA topic because inheritance, containment, and dependency are all easily expressed as relationships over definitional topics (the reference topics that define the elements, sets, and attributes).

• A method for converting the design example to the model representation and for generating the DTD, XSD, and documentation outputs from the model representation.

  The reference implementation uses Ant files to drive XSLT transforms. Because of the specialization dependencies, Ant is helpful for processing designs in dependency order. Because specializations can have wildcards to inherit portions of the base model, it's important to process the base definition before the specialization and to refresh the specialization when the base changes. The specialized maps for DITA By Example themselves are themselves produced by the process.