1、BS ISO/IEC 19757-9:2008ICS 35.240.30NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDInformation technology Document Schema Definition Languages (DSDL)Part 9: Namespace and datatype declaration in Document Type Definitions (DTDs)This British Standard was publishe
2、d under the authority of the Standards Policy and Strategy Committee on 30September 2009 BSI 2009ISBN 978 0 580 54617 4Amendments/corrigenda issued since publicationDate CommentsBS ISO/IEC 19757-9:2008National forewordThis British Standard is the UK implementation of ISO/IEC19757-9:2008.The UK parti
3、cipation in its preparation was entrusted to TechnicalCommittee IST/41, Document description and processing language.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract
4、. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunityfrom legal obligations.BS ISO/IEC 19757-9:2008Reference numberISO/IEC 19757-9:2008(E)ISO/IEC 2008INTERNATIONAL STANDARD ISO/IEC19757-9First edition2008-11-15Information technology Document S
5、chema 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 nommage et de type de donnes dans les dfinitions de type de document (DTD)
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10、n 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 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO/IEC 2008 All rights reser
11、vedBS ISO/IEC 19757-9:2008ISO/IEC 19757-9:2008(E) ISO/IEC 2008 All rights reserved iiiContentsPageForeword ivIntroduction. v1 Scope 12 Normative references 13 Terms and definitions. 24 DTD extension declarations using XML processing instruction syntax. 25 DTD extension declarations using XML documen
12、t syntax. 46 Location and ordering of DTD extension declarations. 57 Inclusion of namespace information in DTDs. 57.1 Associating namespaces with qualified names 57.2 Associating namespaces with unqualified names 57.3 Associating namespace constraints with elements with content model ANY. 68 Inclusi
13、on of datatype information in DTDs 68.1 Associating datatype libraries with qualified datatype names. 68.2 Associating datatype libraries with unqualified datatype names 69 Validity of DTDs and instances. 79.1 Validity of a DTD that includes extension declarations 79.2 Validity of an instance whose
14、associated DTD does not include extension declarations. 79.3 Validity of an instance whose associated DTD includes extension declarations 7Annex A (informative) Example processing model. 9Annex B (informative) Example declarations. 10B.1 Examples in XML processing instruction syntax 10B.2 Example in
15、 XML document syntax. 11BS ISO/IEC 19757-9:2008ISO/IEC 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 bodi
16、es 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 i
17、nternational 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 gi
18、ven 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
19、 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 19757-9 was prepared by Join
20、t Technical Committee ISO/IEC JTC 1, Information technology, 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-
21、grammar-based validation RELAX NG Part 3: Rule-based validation 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 Documen
22、t Type Definitions (DTDs) BS ISO/IEC 19757-9:2008ISO/IEC 19757-9:2008(E) ISO/IEC 2008 All rights reserved vIntroductionThe language of Document Type Definitions (DTDs) was the original schema language defined by W3C XML andwas closely based upon the DTD language defined by ISO 8879:1986. For a varie
23、ty of reasons, both technical andeconomic, many users of XML for document-centric applications, especially among those who were previously (andin some cases continue to be) users of SGML, still favour the use of DTD language for grammar-based schemadefinition in such applications.It is important to
24、provide users that have made a significant investment in DTDs with a migration path that will enablethem 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, wit
25、h all the expense andorganizational upheavals thereby entailed. A sensible migration path should enable such users to continue to useDTDs for as much of the document validation process as can reasonably be managed, but also enable them to reapthe benefits of using those parts of ISO/IEC 19757 that m
26、ost obviously complement and extend the use of DTDsfor validation purposes.It is equally important that the migration path should enable users to continue to use legacy systems that are incapableof using any kind of extension to the DTD language, while at the same time introducing new systems that a
27、re equippedto use such extensions. The method of extension will therefore be such that DTDs with extended functionality arevalid XML DTDs in accordance with W3C XML. It should remain possible to validate an instance that does not makeany use of the extended functionality against a DTD that contains
28、the extended functionality, using legacy systemtools, 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 namespaces, validation
29、 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 currentlyonly possible if ISO/IEC 19757-2 is implemented, but existing DTD users are unlikely to wish to mai
30、ntain parallelRELAX NG and DTD schemas for each application simply as a means of supporting the use of namespaces anddatatypes.For these reasons this part of ISO/IEC 19757 addresses the extension of DTDs to support the declaration ofnamespaces and datatypes.BS ISO/IEC 19757-9:2008BS ISO/IEC 19757-9:
31、2008INTERNATIONAL STANDARD ISO/IEC 19757-9:2008(E)1 ISO/IEC 2008 All rights reservedInformation technology Document Schema DefinitionLanguages (DSDL) Part 9:Namespace and datatype declaration in Document TypeDefinitions (DTDs)1 ScopeThis part of ISO/IEC 19757 defines a language that is designed to e
32、xtend the declarative functionality of an XMLDTD to include declaring one or more namespaces to which some or all of the element and attribute names in a DTD belong, declaring constraints on the content of elements with content model ANY to contain elements whose namesbelong to one or more specified
33、 namespaces, declaring datatypes for elements that contain data content only and for attribute values.Two alternative syntax bindings for this language are defined. The first syntax binding uses XML processinginstructions and is designed to enable declarations in this language to be embedded within
34、an XML DTD withoutinvalidating the DTD or altering its interpretation so far as legacy DTD parsers are concerned. This first syntax alsoprovides a means of associating a DTD with an external declarations subset containing declarations in either syntax.This syntax is defined in Clause 4 using the mod
35、ified 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 definedby a schema that conforms to the RELAX NG Compact Syntax defined in ISO/IEC 19757-2. This syntax is designedto enable declarations in this language
36、to be expressed almost entirely in XML (in this case one XML processinginstruction needs to be inserted in the DTD), to facilitate implementation using existing XML tools, either as anamespace-qualified fragment embedded within an XML instance or as a separate XML document.2 Normative referencesThe
37、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 anyamendments) applies.ISO 8879:1986, Information processing Text and office sy
38、stems Standard Generalized Markup Language(SGML)W3C XML, Extensible Markup Language (XML) 1.0 (Fourth Edition), W3C Recommendation, 16 August 2006,http:/www.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/2
39、006/REC-xml-names-20060816/ISO/IEC 19757-2, Information technology Document Schema Definition Language (DSDL) Part 2: Regular-grammar-based validation (RELAX NG)IETF RFC 3987, Internationalized Resource Identifiers (IRIs), January 2005, http:/www.ietf.org/rfc/rfc3987BS ISO/IEC 19757-9:2008ISO/IEC 19
40、757-9:2008(E)2 ISO/IEC 2008 All rights reserved3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply3.1DSDL-9-aware parservalidating XML processor that is able to interpret and process the extension declarations correctly in accordancewith this part of I
41、SO/IEC 19757, and is therefore able to validate instances whose validity (or otherwise) can only becorrectly determined with reference to those extension declarations3.2external declarations subsetXML resource containing a set of DTD extension declarations either in XML processing instruction syntax
42、 or in XMLdocument syntax in accordance with this part of ISO/IEC 197573.3legacy parservalidating XML processor that is unable to interpret and process extension declarations correctly in accordance withthis part of ISO/IEC 19757, and is therefore unable to validate instances whose validity (or othe
43、rwise) can only becorrectly determined with reference to those extension declarations3.4namespace IRIIRI that maps to a URI that is a namespace name3.5qualified datatype namedatatype name containing a qualifying prefix and a local part separated by a colon :, the prefix of which is boundto the names
44、pace IRI of a datatype library by a datatype library prefix binding declaration as described in this partof ISO/IEC 19757NOTE A datatype library is an identified set of named datatypes. The definition of a datatype library is outside the scope ofthis part of ISO/IEC 19757.3.6unqualified datatype nam
45、edatatype name that does not contain a colon : and therefore contains only a local part4 DTD extension declarations using XML processing instruction syntaxThe following set of syntax productions define how namespace and datatype declarations expressed in accordancewith this part of ISO/IEC 19757 may
46、 be represented as XML processing instructions. Syntax productions forEnumeration and s are given in W3C XML. The syntax production for NCName is given in W3C XML-Names. Thesyntax production for IRI is given in IETF RFC 3987.NOTE See Clause 1 for further information on the intended use of this forma
47、t.DTD-extension-processing-instruction := pio “DSDL-9“ s (namespace-prefix-binding-declaration | namespace-name-binding-declaration | wildcard-namespace-qualifier-declaration | default-datatype-library-declaration | datatype-library-prefix-binding-declaration | datatype-binding-declaration | externa
48、l-declarations-subset-locator) picnamespace-prefix-binding-declaration := “bind-ns-to-prefix“ s “ns-iri=“ namespace-IRI-literal s “prefix=“prefix-literalnamespace-name-binding-declaration := “bind-ns-to-names“ s “ns-iri=“ namespace-IRI-literal s “elem-names=“ name-locator-literalBS ISO/IEC 19757-9:2
49、008ISO/IEC 19757-9:2008(E)3 ISO/IEC 2008 All rights reservedwildcard-namespace-qualifier-declaration := “wildcard-ns“ s “ns-iri-list=“ wildcard-namespace-literal s“elem-names=“ name-locator-literalwildcard-namespace-literal := (lit wildcard-namespace-list lit) | (lita wildcard-namespace-list lita)wildcard-namespace-list := (s)? namespace-IRI (s namespace-IRI)* (s)?name-locator-literal := (lit name-locator-list lit) | (lita name-locator-list lita)name-locator-list := (s)? (Enumeration |
