BS ISO IEC 19757-9-2009 Information technology - Document schema definition languages (DSDL) - Namespace and datatype declaration in document type definitions (DTDs)《信息技术.pdf

1、BS ISO/IEC 19757-9:2008 ICS 35.240.30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Information technology Document Schema Definition Languages (DSDL) Part 9: Namespace and datatype declaration in Document Type Definitions (DTDs)This British Standard was pub

2、lished under the authority of the Standards Policy and Strategy Committee on 30 September 2009 BSI 2009 ISBN 978 0 580 54617 4 Amendments/corrigenda issued since publication Date Comments BS ISO/IEC 19757-9:2008 National foreword This British Standard is the UK implementation of ISO/IEC 19757-9:2008

3、. The UK participation in its preparation was entrusted to Technical Committee IST/41, Document description and processing language. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provi

4、sions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations.BS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008Reference number ISO/IEC 19757-9:2008(E) ISO/IEC 2008INTERNATIONAL STANDARD

5、ISO/IEC 19757-9 First edition 2008-11-15 Information technology Document Schema Definition Languages (DSDL) Part 9: Namespace and datatype declaration in Document Type Definitions (DTDs) Technologies de linformation Langages de dfinition de schma de documents (DSDL) Partie 9: Dclaration despace de n

6、ommage et de type de donnes dans les dfinitions de type de document (DTD) BS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008 ISO/IEC 19757-9:2008(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed

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9、table for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO/IEC 2008 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced

10、 or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01

11、 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO/IEC 2008 All rights reservedBS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008 ISO/IEC 19757-9:2008(E) ISO/IEC 2008 All rights reserved iii Contents Page Foreword iv Introduction. v

12、 1 Scope 1 2 Normative references 1 3 Terms and definitions. 2 4 DTD extension declarations using XML processing instruction syntax. 2 5 DTD extension declarations using XML document syntax. 4 6 Location and ordering of DTD extension declarations. 5 7 Inclusion of namespace information in DTDs. 5 7.

13、1 Associating namespaces with qualified names 5 7.2 Associating namespaces with unqualified names 5 7.3 Associating namespace constraints with elements with content model ANY. 6 8 Inclusion of datatype information in DTDs 6 8.1 Associating datatype libraries with qualified datatype names. 6 8.2 Asso

14、ciating datatype libraries with unqualified datatype names 6 9 Validity of DTDs and instances. 7 9.1 Validity of a DTD that includes extension declarations 7 9.2 Validity of an instance whose associated DTD does not include extension declarations. 7 9.3 Validity of an instance whose associated DTD i

15、ncludes extension declarations 7 Annex A (informative) Example processing model. 9 Annex B (informative) Example declarations. 10 B.1 Examples in XML processing instruction syntax 10 B.2 Example in XML document syntax. 11BS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008 ISO/IEC

16、 19757-9:2008(E) iv ISO/IEC 2008 All rights reservedForeword 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 d

17、evelopment 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-gover

18、nmental, 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 o

19、f 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 vot

20、e. 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 19757-9 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information techn

21、ology, Subcommittee SC 34, Document description and processing languages. ISO/IEC 19757 consists of the following parts, under the general title Information technology Document Schema Definition Languages (DSDL): Part 1: Overview Part 2: Regular-grammar-based validation RELAX NG Part 3: Rule-based v

22、alidation Schematron Part 4: Namespace-based Validation Dispatching Language (NVDL) Part 7: Character Repertoire Description Language (CRDL) Part 8: Document Semantics Renaming Language (DSRL) Part 9: Namespace and datatype declaration in Document Type Definitions (DTDs) BS ISO/IEC 19757-9:2008 BS I

23、SO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008 ISO/IEC 19757-9:2008(E) ISO/IEC 2008 All rights reserved v Introduction The language of Document Type Definitions (DTDs) was the original schema language defined by W3C XML and was closely based upon the DTD language defined by ISO 8879:1986. For a variety

24、 of reasons, both technical and economic, many users of XML for document-centric applications, especially among those who were previously (and in some cases continue to be) users of SGML, still favour the use of DTD language for grammar-based schema definition in such applications. It is important t

25、o provide users that have made a significant investment in DTDs with a migration path that will enable them to adopt ISO/IEC 19757 without having to translate all their existing DTDs to a different schema language, especially as this would oblige them to replace all systems that only work with DTDs,

26、 with all the expense and organizational upheavals thereby entailed. A sensible migration path should enable such users to continue to use DTDs for as much of the document validation process as can reasonably be managed, but also enable them to reap the benefits of using those parts of ISO/IEC 19757

27、 that most obviously complement and extend the use of DTDs for validation purposes. It is equally important that the migration path should enable users to continue to use legacy systems that are incapable of using any kind of extension to the DTD language, while at the same time introducing new syst

28、ems that are equipped to use such extensions. The method of extension will therefore be such that DTDs with extended functionality are valid XML DTDs in accordance with W3C XML. It should remain possible to validate an instance that does not make any use of the extended functionality against a DTD t

29、hat contains the extended functionality, using legacy system tools, and achieve the same result as would be achieved if the DTD did not contain the extended functionality. The most significant validation tasks that cannot be performed using a DTD alone are validation of names with respect to namespa

30、ces, validation of data content and attribute values with respect to datatypes, rules-based validation. Of these three, the last is made possible by implementation of ISO/IEC 19757-3. The first two tasks are currently only possible if ISO/IEC 19757-2 is implemented, but existing DTD users are unlike

31、ly to wish to maintain parallel RELAX NG and DTD schemas for each application simply as a means of supporting the use of namespaces and datatypes. For these reasons this part of ISO/IEC 19757 addresses the extension of DTDs to support the declaration of namespaces and datatypes.BS ISO/IEC 19757-9:20

32、08 BS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008BS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008 INTERNATIONAL STANDARD ISO/IEC 19757-9:2008(E) 1 ISO/IEC 2008 All rights reserved Information technology Document Schema Definition Languages (DSDL) Part 9: Namespace and datatyp

33、e declaration in Document Type Definitions (DTDs) 1 Scope This part of ISO/IEC 19757 defines a language that is designed to extend the declarative functionality of an XML DTD to include declaring one or more namespaces to which some or all of the element and attribute names in a DTD belong, declarin

34、g constraints on the content of elements with content model ANY to contain elements whose names belong to one or more specified namespaces, declaring datatypes for elements that contain data content only and for attribute values. Two alternative syntax bindings for this language are defined. The fir

35、st syntax binding uses XML processing instructions and is designed to enable declarations in this language to be embedded within an XML DTD without invalidating the DTD or altering its interpretation so far as legacy DTD parsers are concerned. This first syntax also provides a means of associating a

36、 DTD with an external declarations subset containing declarations in either syntax. This syntax is defined in Clause 4 using the modified BNF syntax notation used in W3C XML. The second syntax binding uses an XML document syntax and is defined in Clause 5. The syntax rules are defined by a schema th

37、at conforms to the RELAX NG Compact Syntax defined in ISO/IEC 19757-2. This syntax is designed to enable declarations in this language to be expressed almost entirely in XML (in this case one XML processing instruction needs to be inserted in the DTD), to facilitate implementation using existing XML

38、 tools, either as a namespace-qualified fragment embedded within an XML instance or as a separate XML document. 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 referenc

39、es, the latest edition of the referenced document (including any amendments) applies. ISO 8879:1986, Information processing Text and office systems Standard Generalized Markup Language (SGML) W3C XML, Extensible Markup Language (XML) 1.0 (Fourth Edition), W3C Recommendation, 16 August 2006, http:/ww

40、w.w3.org/TR/2006/REC-xml-20060816/ W3C XML-Names, Namespaces in XML 1.0 (Second Edition), W3C Recommendation, 16 August 2006, http:/www.w3.org/TR/2006/REC-xml-names-20060816/ ISO/IEC 19757-2, Information technology Document Schema Definition Language (DSDL) Part 2: Regular- grammar-based validation

41、(RELAX NG) IETF RFC 3987, Internationalized Resource Identifiers (IRIs), January 2005, http:/www.ietf.org/rfc/rfc3987BS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008 BS ISO/IEC 19757-9:2008 ISO/IEC 19757-9:2008(E) 2 ISO/IEC 2008 All rights reserved 3 Terms and definitions For the purposes of this doc

42、ument, the following terms and definitions apply 3.1 DSDL-9-aware parser validating XML processor that is able to interpret and process the extension declarations correctly in accordance with this part of ISO/IEC 19757, and is therefore able to validate instances whose validity (or otherwise) can on

43、ly be correctly determined with reference to those extension declarations 3.2 external declarations subset XML resource containing a set of DTD extension declarations either in XML processing instruction syntax or in XML document syntax in accordance with this part of ISO/IEC 19757 3.3 legacy parser

44、 validating XML processor that is unable to interpret and process extension declarations correctly in accordance with this part of ISO/IEC 19757, and is therefore unable to validate instances whose validity (or otherwise) can only be correctly determined with reference to those extension declaration

45、s 3.4 namespace IRI IRI that maps to a URI that is a namespace name 3.5 qualified datatype name datatype name containing a qualifying prefix and a local part separated by a colon :, the prefix of which is bound to the namespace IRI of a datatype library by a datatype library prefix binding declarati

46、on as described in this part of ISO/IEC 19757 NOTE A datatype library is an identified set of named datatypes. The definition of a datatype library is outside the scope of this part of ISO/IEC 19757. 3.6 unqualified datatype name datatype name that does not contain a colon : and therefore contains o

47、nly a local part 4 DTD extension declarations using XML processing instruction syntax The following set of syntax productions define how namespace and datatype declarations expressed in accordance with this part of ISO/IEC 19757 may be represented as XML processing instructions. Syntax productions f

48、or Enumeration and s are given in W3C XML. The syntax production for NCName is given in W3C XML-Names. The syntax production for IRI is given in IETF RFC 3987. NOTE See Clause 1 for further information on the intended use of this format. DTD-extension-processing-instruction := pio “DSDL-9“ s (namesp

49、ace-prefix-binding-declaration | namespace- name-binding-declaration | wildcard-namespace-qualifier-declaration | default-datatype-library-declaration | datatype- library-prefix-binding-declaration | datatype-binding-declaration | external-declarations-subset-locator) pic namespace-prefix-binding-declaration := “bind-ns-to-prefix“ s “ns-iri=“ namespace-IRI-literal s “prefix=“ prefix-literal namespace-name-binding-declaration := “bind-ns-to-names“ s “ns-iri=“ namespace-IRI-literal s “elem-