ISO/TS 10303-28:2003

TECHNICAL ISO/TS
SPECIFICATION 10303-28
First edition
2003-08-01

Industrial automation systems and
integration — Product data
representation and exchange —
Part 28:
Implementation methods: XML
representations of EXPRESS schemas
and data
Systèmes d'automatisation industrielle et intégration — Représentation
et échange de données de produits —
Partie 28: Méthodes d'implémentation: représentations XML de
schémas et de données EXPRESS




Reference number
ISO/TS 10303-28:2003(E)
©
ISO 2003

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ISO/TS 10303-28:2003(E)
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ISO/TS 10303-28:2003(E)
Content Page
Foreword.viii
Introduction.ix
1 Scope.1
2 Normative references.2
3 Terms, definitions, and abbreviations.3
3.1 Terms defined in ISO 10303-1.3
3.2 Other terms and definitions.3
3.3 Abbreviations.5
3.4 Terminology.5
4 Fundamental concepts, assumptions, and limitations.6
4.1 Early and late binding .6
4.2 Mapping between bindings .6
4.2.1 Use of Architectural forms .7
4.2.2 Use of XSLT.8
4.3 XML markup declaration sets and Document Type Declarations .9
4.4 XML names.9
4.4.1 Name restrictions in XML.9
4.4.2 Use of case in XML element type names .9
4.5 Use of ID, IDREF and the reftype XML attribute .9
4.6 Character coding limitations .10
5 Conformance.10
5.1 Conformance of an XML document .11
5.1.1 Binding conformance .11
5.1.2 Architectural conformance .11
5.1.3 XML document representation categories.11
5.2 Conformance of an XML document element.12
5.3 Conformance of a pre-processor .13
5.4 Conformance of a post-processor.13
5.5 Conformance of a markup declaration generator.13
6 Document level elements.13
6.1 The iso_10303_28 element .14
6.2 Document header information.14
6.2.1 The iso_10303_28_header element .14
6.2.2 The document_name element.14
6.2.3 The time_stamp element.15
6.2.4 The author element .15
6.2.5 The originating_organization element.15
6.2.6 The authorization element .15
6.2.7 The originating_system element.16
6.2.8 The preprocessor_version element .16
6.2.9 The purpose element.16
6.2.10 The documentation element .16
6.3 The schema_population element.16
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6.4 EXPRESS schema descriptive information .18
6.4.1 The express_schema element .18
6.4.2 The schema_text element .19
6.4.3 The schema_decl element.19
6.5 Data descriptive information.19
6.5.1 The express_data element.19
6.5.2 The data_section_header element.20
6.6 Inter-XML document reference information.21
6.6.1 References to remote XML resources .21
6.6.2 Referencing a remote XML element .21
6.6.3 Including components in documents .22
7 Late-bound markup declarations for EXPRESS-defined data.24
7.1 Representation of a schema instance.25
7.2 Representation of an EXPRESS entity instance.26
7.2.1 Representation using the entity_instance element.26
7.2.2 Representation using entity_instance_as_group.27
7.3 Representation of EXPRESS attributes.28
7.3.1 Representation of EXPRESS mandatory explicit attributes.29
7.3.2 Representation of EXPRESS OPTIONAL explicit attributes.30
7.3.3 Representation of EXPRESS INVERSE attributes .30
7.3.4 Representation of DERIVEd attributes .30
7.3.5 Representation of redeclared attributes .31
7.3.6 Representation of explicit attributes redeclared as DERIVEd .31
7.3.7 Representation of attributes redeclared as INVERSE .31
7.4 Representation of EXPRESS attribute values.31
7.4.1 Representation of primitive data types .32
7.4.2 Representation of aggregate data types .34
7.4.3 Representation of defined data types.37
7.4.4 Representation of EXPRESS attribute values that are EXPRESS entity instance
references .39
8 EXPRESS-typed Early Binding (ETEB).41
8.1 Fundamental concepts and assumptions.41
8.1.1 Preconditions .41
8.1.2 EXPRESS entity referencing.41
8.1.3 Multiple supertypes .42
8.1.4 Unmapped EXPRESS concepts.43
8.1.5 Late binding architectural form .43
8.1.6 Inter-subtype constraints.43
8.2 XML markup declaration set.44
8.2.1 Element naming.44
8.2.2 Schema independent declarations.44
8.2.3 EXPRESS schema declaration .46
8.2.4 Defined data types .48
8.2.5 EXPRESS entity data type declarations .51
8.2.6 EXPRESS explicit attribute declarations .55
8.2.7 Subtypes and supertypes.59
8.2.8 Aggregate data types .63
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ISO/TS 10303-28:2003(E)

8.2.9 Interface specifications .66
8.2.10 Constants.69
8.2.11 Derived attributes.70
8.2.12 Declaration set optimizations.70
8.3 Data encoding.70
8.3.1 Representation of EXPRESS entity instances .70
8.3.2 Representation of EXPRESS explicit attributes.71
8.3.3 Representation of DERIVEd attributes .71
8.3.4 Representation of EXPRESS attribute values .71
9 Object Serialization Early Binding (OSEB) .74
9.1 Fundamental Concepts and Assumptions .74
9.1.1 Preconditions .74
9.1.2 Unmapped EXPRESS concepts.74
9.2 OSEB element naming.75
9.2.1 Mapping EXPRESS identifiers to XML.75
9.2.2 Names resulting from EXPRESS named data types.75
9.3 EXPRESS schema-independent element types.76
9.3.1 Elements for simple types.76
9.3.2 Elements for aggregate types.78
9.3.3 The unset element.79
9.3.4 The uos element.79
9.3.5 The external identification elements.80
9.3.6 The spath element.80
9.4 XML declarations for EXPRESS named data types .81
9.4.1 EXPRESS ENUMERATION types .81
9.4.2 EXPRESS SELECT types.81
9.4.3 EXPRESS entity data types.82
9.4.4 EXPRESS non-constructed defined data types .86
9.5 XML declarations for EXPRESS attributes .88
9.5.1 Attribute naming.88
9.5.2 Explicit attributes.90
9.5.3 INVERSE attributes .90
9.5.4 DERIVEd attributes.91
9.5.5 Redeclared attributes .92
9.6 XML attribute types for EXPRESS attributes.92
9.6.1 NUMBER, REAL, INTEGER attributes.92
9.6.2 BOOLEAN attributes .93
9.6.3 LOGICAL attributes.93
9.6.4 STRING attributes.94
9.6.5 BINARY attributes .94
9.6.6 ENUMERATION-typed attributes.95
9.6.7 SELECT-typed attributes .95
9.6.8 EXPRESS entity instance-valued attributes .96
9.6.9 Attributes with non-constructed defined types.96
9.6.10 Attributes with aggregate data types .97
9.7 Creation of express_data content .99
9.7.1 Unit of serialization .99
9.7.2 Representation of EXPRESS entity instances .105
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9.7.3 Representation of the unset element.106
9.8 Representation of EXPRESS attribute values.106
9.8.1 Representation of INTEGER values.106
9.8.2 Representation of REAL and NUMBER values .107
9.8.3 Representation of BOOLEAN values.108
9.8.4 Representation of LOGICAL values .109
9.8.5 Representation of STRING values .110
9.8.6 Representation of BINARY values .111
9.8.7 Representation of ENUMERATION items.111
9.8.8 Representation of EXPRESS entity instances as values of attributes .112
9.8.9 Representation of values of SELECT types .112
9.8.10 Representation of aggregate values.115
9.8.11 Representation of values of non-constructed defined data types .123
10 XML document creation.128
10.1 General XML document structure using binding representation.128
10.2 Representation of EXPRESS schemas.128
10.3 Representation of data .129
10.3.1 Late binding XML documents .129
10.3.2 EXPRESS-typed Early Binding XML documents.130
10.3.3 Object Serialization Early Binding XML documents .132
10.3.4 Mixed representation XML documents.132
10.4 Use of XML Namespaces.133
Annex A (normative) Information object registration.135
Annex B (normative) The XML markup declaration set for late bound data .136
Annex C (normative) Representing EXPRESS schemas .140
Annex D (normative) Base architecture document type definition.168
Annex E (normative) Universal Resource Names for bindings of EXPRESS schemas .169
Annex F (normative) Valid populations of EXPRESS entity instances.170
Annex G (informative) Computer interpretable listings .180
Annex H (informative) Technical Discussions .181
Annex I (informative) Examples.187
Annex J (informative) User Guide to XML Encodings in 10303-28.295
Annex K (informative) Mapping of Object Serialization Early Binding to Late Binding using XSLT301
Annex L (informative) Mapping of EXPRESS-Typed Early Binding to Late Binding using XSLT 313
Annex M (informative)  Mapping from the EXPRESS Typed Early Binding to the Object
Serialization Early Binding .323
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ISO/TS 10303-28:2003(E)

Annex N (informative)  Mapping from the Late Binding to the Object Serialization Early Binding 334
Bibliography.351
Index.352

Figures
Figure 1 - Relationship between markup declaration sets.7

Tables
Table J.1 Data encoding size comparison .299
Table J.2 Binding approaches to design issues .300

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ISO/TS 10303-28:2003(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has
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International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
In other circumstances, particularly when there is an urgent market requirement for such documents, a
technical committee may decide to publish other types of normative document:
— an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in
an ISO working group and is accepted for publication if it is approved by more than 50 % of the members
of the parent committee casting a vote;
— an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical
committee and is accepted for publication if it is approved by 2/3 of the members of the committee
casting a vote.
An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a
further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is
confirmed, it is reviewed again after a further three years, at which time it must either be transformed into an
International Standard or be withdrawn.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO/TS 10303-28 was prepared by Technical Committee ISO/TC 184, Industrial automation systems and
integration, Subcommittee SC 4, Industrial data.
This International Standard is organized as a series of parts, each published separately. The parts of
ISO 10303 fall into one of the following series: description methods, integrated resources, application
interpreted constructs, application protocols, abstract test suites, implementation methods, and conformance
testing. The series are described in ISO 10303-1. A complete list of parts of ISO 10303 is available from the
Internet:
.
This part of ISO 10303 is a member of the implementation methods series.
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ISO/TS 10303-28:2003(E)
Introduction
ISO 10303 is an International Standard for the computer-interpretable representation of product
information and for the exchange of product data. The objective is to provide a neutral mechanism
capable of describing products throughout their life cycle. This mechanism is suitable not only for
neutral file exchange, but also as a basis for implementing and sharing product databases, and as a
basis for archiving.
This part of ISO 10303 specifies means by which schemas specified using the EXPRESS language
(ISO 10303-11) and data governed by EXPRESS schemas can be represented as an XML document
(Extensible Markup Language W3C Recommendation). Readers of this part of ISO 10303 should
have knowledge of the EXPRESS language, XML and XML-related standards in order to understand
its technical content.
For the representation of EXPRESS schemas, this part of ISO 10303 specifies an XML markup
declaration set based on the syntax of the EXPRESS language. EXPRESS text representation of
schemas is also supported.
For the representation of data corresponding to an EXPRESS schema, this part of ISO 10303 takes
two broad approaches. One approach is to specify a single markup declaration set that is independent
of the EXPRESS schema and can represent data for any schema. This approach is calle
...