XML in TC 184 SC4
The STEP standard for the exchange of product model data utilises a data definition
language known as EXPRESS to define its data models. EXPRESS can be mapped to a variety
of data exchange and sharing forms, such as flat files, databases, language bindings and
XML/XML schema. Thus any EXPRESS data model - in STEP, PLIB or any of the other SC4 standards
has a direct mapping to XML - although it has been a general experience that the file sizes of
the XML representations have been grossly inflated.
The key publication is therefore one of our series of implementation methods ISO 10303-28:
Implementation methods: XML representations of EXPRESS schemas and data
This standard provides a representation according to the syntax of Extensible Markup Language
(XML) of product data defined using ISO 10303-11 (the EXPRESS language) and/or for EXPRESS schemas.
The mappings from the EXPRESS language to the syntax of the representation are specified. Any
EXPRESS schema or schemas and the data they describe can be represented.
The first edition provides a choice of early binding and a single late binding, and is currently
under publication. The second edition will define a single default mapping from EXPRESS to an
XML-schema based binding, which will use XML reference rather than XML containment and will
define a configuration language that allows control over some aspects of the XML structure.