ISO/IEC 19757-3:2016
(Main)Information technology — Document Schema Definition Languages (DSDL) — Part 3: Rule-based validation — Schematron
Information technology — Document Schema Definition Languages (DSDL) — Part 3: Rule-based validation — Schematron
ISO/IEC 19757-3:2016 specifies Schematron, a schema language for XML. This part of ISO/IEC 19757 establishes requirements for Schematron schemas and specifies when an XML document matches the patterns specified by a Schematron schema.
Technologies de l'information — Langages de définition de schéma de documents (DSDL) — Partie 3: Validation de règles orientées — Schematron
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INTERNATIONAL ISO/IEC
STANDARD 19757-3
Second edition
2016-01-15
Information technology — Document
Schema Definition Languages
(DSDL) —
Part 3:
Rule-based validation — Schematron
Technologies de l’information — Langages de définition de schéma de
documents (DSDL) —
Partie 3: Validation de règles orientées — Schematron
Reference number
ISO/IEC 19757-3:2016(E)
©
ISO/IEC 2016
---------------------- Page: 1 ----------------------
ISO/IEC 19757-3:2016(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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copyright@iso.org
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ii © ISO/IEC 2016 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/IEC 19757-3:2016(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Notation . 4
5 Syntax . 4
5.1 Well-formedness. 4
5.2 Namespace. 4
5.3 Whitespace . 4
5.4 Core elements . 4
5.4.1 active element . 4
5.4.2 assert element . 4
5.4.3 extends element . 5
5.4.4 include element . 5
5.4.5 let element. 5
5.4.6 name element . 5
5.4.7 ns element . 6
5.4.8 param element . 6
5.4.9 pattern element . 6
5.4.10 phase element . 6
5.4.11 report element . 6
5.4.12 rule element . 7
5.4.13 schema element . 7
5.4.14 value-of element . . 7
5.5 Ancillary elements and attributes . 8
5.5.1 diagnostic element . 8
5.5.2 diagnostics element . 8
5.5.3 dir element. 8
5.5.4 emph element . 8
5.5.5 flag attribute . 8
5.5.6 fpi attribute . 8
5.5.7 icon attribute . 8
5.5.8 p element . 8
5.5.9 properties element . 8
5.5.10 property element . . 9
5.5.11 role attribute . 9
5.5.12 see attribute . 9
5.5.13 span element . 9
5.5.14 subject attribute . 9
5.5.15 title element . 9
6 Semantics . 9
6.1 Validation function . 9
6.2 Minimal syntax .10
6.3 Abstract pattern processing .10
6.4 Query language binding .12
6.5 Order and side-effects .13
7 Conformance .13
7.1 Simple conformance .13
7.2 Full conformance.13
Annex A (normative) RELAX NG schema for Schematron .15
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ISO/IEC 19757-3:2016(E)
Annex B (normative) Schematron schema for additional constraints .19
Annex C (normative) Default query language binding .20
Annex D (informative) Schematron Validation Report Language .21
Annex E (informative) Design requirements .26
Annex F (informative) Use of Schematron as a vocabulary .27
Annex G (informative) Use of Schematron for multi-lingual schemas .28
Annex H (normative) Query language binding for XSLT 2 .29
Annex I (informative) Query language binding for XPath 2 .31
Annex J (informative) Query language binding for EXSLT .32
Annex K (informative) Query language binding for STX .33
Annex L (informative) Example usage of Schematron properties .34
Bibliography .36
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ISO/IEC 19757-3:2016(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work. In the field of information technology, ISO and IEC have established a joint technical committee,
ISO/IEC JTC 1.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for
the different types of document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/IEC JTC 1, Information technology, Subcommittee
SC 34, Document description and processing languages.
This second edition cancels and replaces the first edition (ISO/IEC 19757-3:2006), which has been
technically revised.
ISO/IEC 19757 consists of the following parts, under the general title Information technology —
Document Schema Definition Languages (DSDL):
— Part 2: Regular-grammar-based validation — RELAX NG
— Part 3: Rule-based validation — Schematron
— Part 4: Namespace-based Validation Dispatching Language (NVDL)
— Part 5: Extensible Datatypes
— Part 7: Character Repertoire Description Language (CREPDL)
— Part 8: Document Semantics Renaming Language (DSRL)
— Part 9: Namespace and datatype declaration in Document Type Definitions (DTDs)
— Part 11: Schema association
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ISO/IEC 19757-3:2016(E)
Introduction
ISO/IEC 19757 defines a set of Document Schema Definition Languages (DSDL) that can be used to specify
one or more validation processes performed against Extensible Stylesheet Language (XML) or Standard
Generalized Markup Language (SGML) documents. [XML is an application profile SGML (see ISO 8879).]
A document model is an expression of the constraints to be placed on the structure and content of
documents to be validated with the model. A number of technologies have been developed through
various formal and informal consortia since the development of Document Type Definitions (DTDs)
as part of ISO 8879, notably by the World Wide Web Consortium (W3C) and the Organization for the
Advancement of Structured Information Standards (OASIS). A number of validation technologies are
standardized in DSDL to complement those already available as standards or from industry.
To validate that a structured document conforms to specified constraints in structure and content
relieves the potentially many applications acting on the document from having to duplicate the task
of confirming that such requirements have been met. Historically, such tasks and expressions have
been developed and utilized in isolation, without consideration of how the features and functionality
available in other technologies might enhance validation objectives.
The main objective of ISO/IEC 19757 is to bring together different validation-related tasks and
expressions to form a single extensible framework that allows technologies to work in series or in
parallel to produce a single or a set of validation results. The extensibility of DSDL accommodates
validation technologies not yet designed or specified.
In the past, different design and use criteria have led users to choose different validation technologies
for different portions of their information. Bringing together information within a single XML
document sometimes prevents existing document models from being used to validate sections of data.
By providing an integrated suite of constraint description languages that can be applied to different
subsets of a single XML document, ISO/IEC 19757 allows different validation technologies to be
integrated under a well-defined validation policy.
The structure of this part of ISO/IEC 19757 is as follows. Clause 5 describes the syntax of an ISO
Schematron schema. Clause 6 describes the semantics of a correct ISO Schematron schema; the
semantics specify when a document is valid with respect to an ISO Schematron schema. Clause 7
describes conformance requirements for implementations of ISO Schematron validators. Annex A is a
normative annex providing the ISO/IEC 19757-2 (RELAX NG) schema for ISO Schematron. Annex B is a
normative annex providing the ISO Schematron schema for constraints in ISO Schematron that cannot
be expressed by the schema of Annex A. Annex C is a normative annex providing the default query
language binding to XSLT1. Annex D is a non-normative annex providing an ISO/IEC 19757-2 (RELAX
NG compact syntax) schema and corresponding ISO Schematron schema for a simple XML language
Schematron Validation Report Language. Annex E is a non-normative annex providing motivating
design requirements for ISO Schematron. Annex F is a normative annex allowing certain Schematron
elements to be used in external vocabularies. Annex G is a non-normative annex with a simple example
of a multi-lingual schema.
This edition is backwards compatible with ISO/IEC 19757-3:2006, supercedes it, and augments it with
the following capabilities: patterns may validate different documents, the inclusion mechanism has been
supplemented by an enhanced extension mechanism, assertions may have linked properties, and SVRL
may take richer text. As well, this edition provides extra query language bindings, in particular for XSLT2.
Considered as a document type, a Schematron schema contains natural-language assertions concerning
a set of documents, marked up with various elements and attributes for testing these natural-language
assertions, and for simplifying and grouping assertions.
Considered theoretically, a Schematron schema reduces to a non-chaining rule system whose terms
are Boolean functions invoking an external query language on the instance and other visible XML
documents, with syntactic features to reduce specification size and to allow efficient implementation.
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ISO/IEC 19757-3:2016(E)
Considered analytically, Schematron has two characteristic high-level abstractions: the pattern and the
phase. These allow the representation of non-regular, non-sequential constraints that ISO/IEC 19757-2
cannot specify and various dynamic or contingent constraints.
[2]
This part of ISO/IEC 19757 is based on the Schematron assertion language. The let element is based
[4]
on XCSL. Other features arise from the half-dozen early Open Source implementations of Schematron
in diverse programming languages and from discussions in electronic forums by Schematron users and
implementers.
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INTERNATIONAL STANDARD ISO/IEC 19757-3:2016(E)
Information technology — Document Schema Definition
Languages (DSDL) —
Part 3:
Rule-based validation — Schematron
1 Scope
This part of ISO/IEC 19757 specifies Schematron, a schema language for XML. This part of ISO/IEC 19757
establishes requirements for Schematron schemas and specifies when an XML document matches the
patterns specified by a Schematron schema.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE Each of the following documents has a unique identifier that is used to cite the document in the text.
The unique identifier consists of the part of the reference up to the first comma.
1)
XPath, XML Path Language (XPath) Version 1.0, W3C Recommendation, 16 November 1999,
2)
XPath2, XML Path Language (XPath) 2.0, W3C Recommendation, 23 January 2007,
XPath2 Functions, XQuery 1.0 and XPath 2.0 Functions and Operators, W3C Recommendation, 23
3)
January 2007,
4)
XSLT1, XSL Transformations (XSLT) Version 1.0, W3C Recommendation, 16 November 1999,
5)
XSLT2, XSL Transformations (XSLT) Version 2.0, W3C Recommendation, 23 January 2007,
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
abstract pattern
pattern in a rule that has been parameterized to enable reuse
3.2
abstract rule
collection of assertions which can be included in other rules but which does not fire itself
1) http://www.w3.org/TR/xpath
2) http://www.w3.org/TR/xpath20/
3) http://www.w3.org/TR/xpath-functions/
4) http://www.w3.org/TR/xslt
5) http://www.w3.org/TR/xslt20/
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ISO/IEC 19757-3:2016(E)
3.3
active pattern
pattern belonging to the active phase
3.4
active phase
one particular phase, whose patterns are used for validation
3.5
assertion
natural-language assertion with corresponding assertion test and ancillary attributes: assertions are
marked up with assert and report elements
3.6
assertion test
assertion modelled or implemented by a Boolean query
Note 1 to entry: An assertion test “succeeds” or “fails”.
3.7
compound document
notional instance document which has been divided into the original instance and a number of
subordinate well-formed XML documents
Note 1 to entry: These subordinate documents may also contain schema-like information.
3.8
correct schema
schema that satisfies all the requirements of this part of ISO/IEC 19757
3.9
diagnostic
named natural language statements providing information to end-users of validators concerning the
expected and actual values together with repair hints
3.10
elaborated rule context expression
single rule context expression which explicitly disallows items selected by lexically previous rule
contexts in the same pattern
3.11
good schema
correct schema with queries which terminate and do not add constraints to those of the natural-
language assertions
Note 1 to entry: It may not be possible to compute that a schema is good.
3.12
implementation
implementation of a Schematron validator
3.13
name
token with no whitespace characters
3.14
natural-language assertion
natural-language statement expressing some part of a pattern
Note 1 to entry: A natural-language assertion is “met” or “unmet”.
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ISO/IEC 19757-3:2016(E)
3.15
pattern
named structure in instances specified in a schema by a lexically-ordered collection of rules
3.16
phase
named, unordered collection of patterns; patterns may belong to more than one phase; two names,
#ALL and #DEFAULT, are reserved with particular meanings
3.17
progressive validation
validation of constraints in stages determined or grouped to some extent by the schema author rather
than, for example, entirely determined by document order
3.18
property
named data giving additional metadata on an assertion or report
3.19
query language binding
named set, specified in a document called a Query Language Binding, of the languages and conventions
used for assertion tests, rule-context expressions and so on, by a particular Schematron implementation
3.20
rule
unordered collection of assertions with a rule-context expression and ancillary attributes
3.21
rule context
element or other information item used for assertion tests
Note 1 to entry: A rule is said to fire when an information item matches the rule context.
3.22
rule-context expression
query to specify subjects
Note 1 to entry: A rule-context is said to match an information item when that information item has not been
matched by any lexically-previous rule context expressions in the same pattern and the information item is one
of the information items that the query would specify.
3.23
schema
specification of a set of XML documents
3.24
subject
particular information item which corresponds to the object of interest of the natural-language
assertions and typically is matched by the context expression of a rule
3.25
valid with respect to a schema
member of the set of XML documents described by the schema: an instance document is valid if no
assertion tests in fired rules of active patterns fail
3.26
variable
constant value, evaluated within the parent schema, phase, pattern or rule and scoped within the
parent schema, phase, pattern or rule
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ISO/IEC 19757-3:2016(E)
4 Notation
This part of ISO/IEC 19757 uses XPath to identify information items in Schematron schemas.
5 Syntax
5.1 Well-formedness
A Schematron schema shall be a well-formed XML document, according to the version of XML used.
5.2 Namespace
All elements shown in the grammar for Schematron are qualified with the namespace URI [IRI]:
http://purl.oclc.org/dsdl/schematron
In subsequent clauses, the prefix sch is taken as bound to the Schematron namespace URI for exposition
purposes. The prefix sch is not reserved or required by this part of ISO/IEC 19757. Any element can also
have foreign attributes in addition to the attributes shown in the grammar. A foreign attribute is an
attribute with a name whose namespace URI is neither the empty string nor the Schematron namespace
URI. Any non-empty element may have foreign child elements in addition to the child elements shown in
the grammar. A foreign element is an element with a name whose namespace URI is not the Schematron
namespace URI. There are no constraints on the relative position of foreign child elements with respect
to other child elements.
5.3 Whitespace
Any element can also have as children strings that consist entirely of whitespace characters, where
a whitespace character is one of U+0020, U+009, U+00D or U+00A. There are no constraints on the
relative position of whitespace string children with respect to child elements.
NOTE Leading and trailing whitespace should be stripped from attributes defined by this part. Whitespace
should be collapsed in elements defined by this part that allow text. Whitespace may be stripped from elements
defined by this part that do not allow text.
5.4 Core elements
The grammar for Schematron elements is given in Annex A.
5.4.1 active element
The required pattern attribute is a reference to a pattern that is active in the current phase.
5.4.2 assert element
An assertion made about the context nodes. The data content is a natural-language assertion. The required
test attribute is an assertion test evaluated in the current context. If the test evaluates positive, the
report succeeds. The optional diagnostics attribute is a reference to further diagnostic information.
The natural-language assertion shall be a positive statement of a constraint.
The icon, see and fpi attributes allow rich interfaces and documentation. They are defined below.
The flag attribute allows more detailed outcomes. It is defined below.
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ISO/IEC 19757-3:2016(E)
The role and subject attributes allow explicit identification of some part of a pattern. They are
defined below.
NOTE The natural-language assertion may contain informat
...
DRAFT INTERNATIONAL STANDARD
ISO/IEC DIS 19757-3
ISO/IEC JTC 1/SC 34 Secretariat: JISC
Voting begins on: Voting terminates on:
2014-12-01 2015-03-01
Information technology — Document Schema Definition
Languages (DSDL) —
Part 3:
Rule-based validation — Schematron
Technologies de l’information — Langages de définition de schéma de documents (DSDL) —
Partie 3: Validation de règles orientées — Schematron
ICS: 35.240.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/IEC DIS 19757-3:2014(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO/IEC 2014
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ISO/IEC DIS 19757-3:2014(E)
Copyright notice
This ISO document is a Draft International Standard and is copyright-protected by ISO. Except as
permitted under the applicable laws of the user’s country, neither this ISO draft nor any extract
from it may be reproduced, stored in a retrieval system or transmitted in any form or by any means,
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Requests for permission to reproduce should be addressed to either ISO at the address below or ISO’s
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Fax + 41 22 749 09 47
E-mail copyright@iso.org
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Reproduction may be subject to royalty payments or a licensing agreement.
Violators may be prosecuted.
ii © ISO 2014 – All rights reserved
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ISO/IEC DIS 19757-3
Contents Page
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Notation . 4
5 Syntax . 4
5.1 Well-formedness . 4
5.2 Namespace . 4
5.3 Whitespace . 4
5.4 Core Elements . 4
5.4.1 active element . 4
5.4.2 assert element . 4
5.4.3 extends element . 5
5.4.4 include element . 5
5.4.5 let element . 5
5.4.6 name element . 6
5.4.7 ns element . 6
5.4.8 param element . 6
5.4.9 pattern element . 6
5.4.10 phase element . 6
5.4.11 report element . 7
5.4.12 rule element . 7
5.4.13 schema element . 7
5.4.14 value-of element . 7
5.5 Ancillary Elements and Attributes . 8
5.5.1 diagnostic element . 8
5.5.2 diagnostics element . 8
5.5.3 dir element . 8
5.5.4 emph element . 8
5.5.5 flag attribute . 8
5.5.6 icon attribute . 8
5.5.7 p element . 8
5.5.8 properties element . 8
5.5.9 property element . 9
5.5.10 role attribute . 9
5.5.11 see attribute . 9
5.5.12 span element . 9
5.5.13 subject attribute . 9
5.5.14 title element . 9
6 Semantics . 10
6.1.1 Validation Function . 10
6.2 Minimal Syntax . 10
6.3 Abstract pattern processing . 11
6.4 Query Language Binding . 12
6.5 Order and side-effects . 13
7 Conformance . 14
7.1 Simple Conformance . 14
© ISO/IEC 2014 – All rights reserved iii
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ISO/IEC DIS 19757-3
7.2 Full Conformance .14
Annex A (normative) RELAX NG schema for Schematron .15
Annex B (normative) Schematron Schema for Additional Constraints .19
Annex C (normative) Default Query Language Binding .20
Annex D (informative) Schematron Validation Report Language .21
D.1 Description .21
D.2 RELAX NG Compact Syntax Schema .21
D.3 Schematron Schema .23
Annex E (informative) Design Requirements .27
Annex F (informative) Use of Schematron as a Vocabulary .28
Annex G (informative) Use of Schematron for Multi-Lingual Schemas .29
Annex H (normative) Query Language Binding for XSLT 2 .30
Annex I (informative) Query Language Binding for XPath 2 .32
Annex J (informative) Query Language Binding for EXSLT .33
Annex K (informative) Query Language Binding for STX .34
Annex L (informative) Example usage of Schematron Properties .35
L.1 Running Example.35
L.2 Annotation with controlled vocabulary information .35
L.3 Annotation with static information .35
L.4 Annotation with static structured information .35
L.5 Type annotation with XSD Simple Type .36
L.6 Type annotation with dynamic information .36
L.7 Type annotation with dynamic structured information .36
L.8 Annotation with ISO19757-7 character repertoire reference .36
L.9 SVRL document .36
Bibliography .37
iv © ISO/IEC 2014 – All rights reserved
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ISO/IEC DIS 19757-3
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are members of
ISO or IEC participate in the development of International Standards through technical committees
established by the respective organization to deal with particular fields of technical activity. ISO and IEC
technical committees collaborate in fields of mutual interest. Other international organizations, governmental
and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information
technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
ISO/IEC 19757-3 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 34, Document description and processing languages.
This second edition cancels and replaces the first. edition (ISO/IEC 19757-3:2006), of which has been
technically revised.
ISO/IEC 19757 consists of the following parts, under the general title Information technology — Document
Schema Definition Languages (DSDL):
Part 2: Regular-grammar-based validation -- RELAX NG
Part 3: Rule-based validation -- Schematron
Part 4: Namespace-based Validation Dispatching Language (NVDL)
Part 5: Extensible Datatypes
Part 7: Character Repertoire Description Language (CREPDL)
Part 8: Document Semantics Renaming Language (DSRL)
Part 9: Namespace and datatype declaration in Document Type Definitions (DTDs)
Part 11: Schema association
© ISO/IEC 2014 – All rights reserved v
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ISO/IEC DIS 19757-3
Introduction
ISO/IEC 19757 defines a set of Document Schema Definition Languages (DSDL) that can be used to specify
one or more validation processes performed against Extensible Stylesheet Language (XML) or Standard
Generalized Markup Language (SGML) documents. (XML is an application profile SGML ISO 8879:1986.)
A document model is an expression of the constraints to be placed on the structure and content of documents
to be validated with the model. A number of technologies have been developed through various formal and
informal consortia since the development of Document Type Definitions (DTDs) as part of ISO 8879, notably
by the World Wide Web Consortium (W3C) and the Organization for the Advancement of Structured
Information Standards (OASIS). A number of validation technologies are standardized in DSDL to
complement those already available as standards or from industry.
To validate that a structured document conforms to specified constraints in structure and content relieves the
potentially many applications acting on the document from having to duplicate the task of confirming that such
requirements have been met. Historically, such tasks and expressions have been developed and utilized in
isolation, without consideration of how the features and functionality available in other technologies might
enhance validation objectives.
The main objective of ISO/IEC 19757 is to bring together different validation-related tasks and expressions to
form a single extensible framework that allows technologies to work in series or in parallel to produce a single
or a set of validation results. The extensibility of DSDL accommodates validation technologies not yet
designed or specified.
In the past, different design and use criteria have led users to choose different validation technologies for
different portions of their information. Bringing together information within a single XML document sometimes
prevents existing document models from being used to validate sections of data. By providing an integrated
suite of constraint description languages that can be applied to different subsets of a single XML document,
ISO/IEC 19757 allows different validation technologies to be integrated under a well-defined validation policy.
The structure of this part of ISO/IEC 19757 is as follows. Clause 5 describes the syntax of an ISO Schematron
schema. Clause 6 describes the semantics of a correct ISO Schematron schema; the semantics specify when
a document is valid with respect to an ISO Schematron schema. Clause 7 describes conformance
requirements for implementations of ISO Schematron validators. Annex A is a normative annex providing the
ISO/IEC 19757-2 (RELAX NG) schema for ISO Schematron. Annex B is a normative annex providing the ISO
Schematron schema for constraints in ISO Schematron that cannot be expressed by the schema of Annex A.
Annex C is a normative annex providing the default query language binding to XSLT1. Annex D is a non-
normative annex providing a ISO/IEC 19757-2 (RELAX NG compact syntax) schema and corresponding ISO
Schematron schema for a simple XML language Schematron Validation Report Language.Annex E is a non-
normative annex providing motivating design requirements for ISO Schematron. Annex F is a normative
annex allowing certain Schematron elements to be used in external vocabularies. Annex G is a non-normative
annex with a simple example of a multi-lingual schema.
This edition is backwards compatible with IS19757-3:2006, supercedes it, and augments it with the following
capabilities: patterns may validate different documents, the inclusion mechanism has been supplemented by
an enhanced extension mechanism, assertions may have linked properties, and SVRL may take richer text.
As well, this edition provides extra query language bindings, in particular for XSLT2.
Considered as a document type, a Schematron schema contains natural-language assertions concerning a
set of documents, marked up with various elements and attributes for testing these natural-language
assertions, and for simplifying and grouping assertions.
Considered theoretically, a Schematron schema reduces to a non-chaining rule system whose terms are
Boolean functions invoking an external query language on the instance and other visible XML documents, with
syntactic features to reduce specification size and to allow efficient implementation.
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ISO/IEC DIS 19757-3
Considered analytically, Schematron has two characteristic high-level abstractions: the pattern and the phase.
These allow the representation of non-regular, non-sequential constraints that Part 2 cannot specify, and
various dynamic or contingent constraints.
This part of ISO/IEC 19757 is based on the Schematron[2] assertion language. The let element is based on
XCSL[4]. Other features arise from the half-dozen early Open Source implementations of Schematron in
diverse programming languages and from discussions in electronic forums by Schematron users and
implementers
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DRAFT INTERNATIONAL STANDARD ISO/IEC DIS 19757-3:2014(E)
Information technology — Document Schema Definition
Languages (DSDL) — Part 3: Rule-based Validation -
Schematron
1 Scope
This part of ISO/IEC 19757 specifies Schematron, a schema language for XML. This part of ISO/IEC 19757
establishes requirements for Schematron schemas and specifies when an XML document matches the
patterns specified by a Schematron schema.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
NOTE Each of the following documents has a unique identifier that is used to cite the document in the text. The unique
identifier consists of the part of the reference up to the first comma.
IRI, RFC 3987, IETF Request for Comment, Current version, http://tools.ietf.org/html/rfc3987
W3C XML 1.0, Extensible Markup Language (XML) 1.0 (Fourth Edition), W3C Recommendation, 14 June
2006, http://www.w3.org/TR/2006/PER-xml-20060614/
XPath, XML Path Language (XPath) Version 1.0, W3C Recommendation, 16 November
1999,http://www.w3.org/TR/xpath
XPath2, XML Path Language (XPath) 2.0, W3C Recommendation, 23 January 2007,
http://www.w3.org/TR/xpath20/
XPath2 Functions, XQuery 1.0 and XPath 2.0 Functions and Operators, W3C Recommendation, 23 January
2007, http://www.w3.org/TR/xpath-functions/
XDM, XQuery 1.0 and XPath 2.0 Data Model (XDM), W3C Recommendation, 23 January 2007,
http://www.w3.org/TR/xpath-datamodel/
XSLT1, XSL Transformations (XSLT) Version 1.0, W3C Recommendation, 16 November 1999,
http://www.w3.org/TR/xslt
XSLT2, XSL Transformations (XSLT) Version 2.0, W3C Recommendation, 23 January 2007,
http://www.w3.org/TR/xslt20/
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply:
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ISO/IEC DIS 19757-3
3.1
abstract pattern
pattern in a rule that has been parameterized to enable reuse
3.2
abstract rule
collection of assertions which can be included in other rules but which does not fire itself
3.3
active pattern
pattern belonging to the active phase
3.4
active phase
one particular phase, whose patterns are used for validation
3.5
assertion
natural-language assertion with corresponding assertion test and ancillary attributes: assertions are marked
up with assert and report elements
3.6
assertion test
assertion modelled or implemented by a Boolean query; an assertion test "succeeds" or "fails"
3.7
compound document
a notional instance document which has been divided into the original instance and a number of subordinate
well-formed XML documents. These subordinate documents may also contain schema-like information.
3.8
correct schema
schema that satisfies all the requirements of this part of ISO/IEC 19757
3.9
diagnostic
named natural language statements providing information to end-users of validators concerning the
expected and actual values together with repair hints
3.10
elaborated rule context expression
single rule context expression which explicitly disallows items selected by lexically previous rule contexts in
the same pattern
3.11
good schema
correct schema with queries which terminate and do not add constraints to those of the natural-language
assertions. Note: It may not be possible to compute that a schema is good.
3.12
implementation
implementation of a Schematron validator
3.13
name
token with no whitespace characters
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ISO/IEC DIS 19757-3
3.14
natural-language assertion
natural-language statement expressing some part of a pattern; a natural-language assertion is "met" or
"unmet"
3.15
pattern
named structure in instances specified in a schema by a lexically-ordered collection of rules
3.16
phase
named, unordered collection of patterns; patterns may belong to more than one phase; two names, #ALL and
#DEFAULT, are reserved with particular meanings
3.17
progressive validation
the validation of constraints in stages determined or grouped to some extent by the schema author rather than,
for example, entirely determined by document order
3.18
property
named data giving additional metadata on an assertion or report
3.19
query language binding
named set, specified in a document called a Query Language Binding, of the languages and conventions used
for assertion tests, rule-context expressions and so on, by a particular Schematron implementation.
3.20
rule
unordered collection of assertions with a rule-context expression and ancillary attributes
3.21
rule context
element or other information item used for assertion tests; a rule is said to fire when an information item
matches the rule context
3.22
rule-context expression
a query to specify subjects; a rule-context is said to match an information item when that information item has
not been matched by any lexically-previous rule context expressions in the same pattern and the information
item is one of the information items that the query would specify
3.23
schema
specification of a set of XML documents
3.24
subject
particular information item which corresponds to the object of interest of the natural-language assertions and
typically is matched by the context expression of a rule
3.25
valid with respect to a schema
member of the set of XML documents described by the schema: an instance document is valid if no assertion
tests in fired rules of active patterns fail
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ISO/IEC DIS 19757-3
3.26
variable
constant value, evaluated within the parent schema, phase, pattern or rule and scoped within the parent
schema, phase, pattern or rule
4 Notation
This part of ISO/IEC 19757 uses XPath to identify information items in Schematron schemas.
5 Syntax
5.1 Well-formedness
A Schematron schema shall be a well-formed XML document, according to the version of XML used.
5.2 Namespace
All elements shown in the grammar for Schematron are qualified with the namespace URI [IRI]:
http://purl.oclc.org/dsdl/schematron
In subsequent clauses, the prefix sch is taken as bound to the Schematron namespace URI for exposition
purposes. The prefix sch is not reserved or required by this part of ISO/IEC 19757. Any element can also have
foreign attributes in addition to the attributes shown in the grammar. A foreign attribute is an attribute with a
name whose namespace URI is neither the empty string nor the Schematron namespace URI. Any non-empty
element may have foreign child elements in addition to the child elements shown in the grammar. A foreign
element is an element with a name whose namespace URI is not the Schematron namespace URI. There are
no constraints on the relative position of foreign child elements with respect to other child elements.
5.3 Whitespace
Any element can also have as children strings that consist entirely of whitespace characters, where a
whitespace character is one of U+0020, U+009, U+00D or U+00A. There are no constraints on the relative
position of whitespace string children with respect to child elements.
NOTE Leading and trailing whitespace should be stripped from attributes defined by this part. Whitespace should be
collapsed in elements defined by this part that allow text. Whitespace may be stripped from elements defined by this part
that do not allow text.
5.4 Core Elements
The grammar for Schematron elements is given in Annex A.
5.4.1 active element
The required pattern attribute is a reference to a pattern that is active in the current phase.
5.4.2 assert element
An assertion made about the context nodes. The data content is a natural-language assertion. The required
test attribute is an assertion test evaluated in the current context. If the test evaluates positive, the report
succeeds. The optional diagnostics attribute is a reference to further diagnostic information.
The natural-language assertion shall be a positive statement of a constraint.
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ISO/IEC DIS 19757-3
The icon, see and fpi attributes allow rich interfaces and documentation. They are defined below.
The flag attribute allows more detailed outcomes. It is defined below.
The role and subject attributes allow explicit identification of some part of a pattern. They are defined
below.
NOTE The natural-language assertion may contain information about actual values in addition
...
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