OMGXMLMetadataInterchange (XMI)Specification Version 1.2, January 2002 Copyright 1998, Cooperative Research Centre for Distributed Systems Technology (DSTC) Copyright 1998, Daimler-Benz Copyright 1998, Fujitsu Copyright 1998, International Business Machines Corporation Copyright 1998, Oracle Corporation Copyright 1998, Platinum Technology, Inc. Copyright 1998, Recerca Information Copyright 1998, Softeam Copyright 1998, Unisys Corporation The companies listed above have granted to the Object Management Group, Inc. (OMG) a nonexclusive, royalty-free, paid up, worldwide license to copy and distribute this document and to modify this document and distribute copies of the mod- ified version. Each of the copyright holders listed above has agreed that no person shall be deemed to have infringed the copyright in the included material of any such copyright holder by reason of having used the specification set forth herein or having conformed any computer software to the specification. 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As part of this process we encourage readers to report any ambiguities, inconsistencies, or inaccuracies they may find by completing the Issue Reporting Form listed on the main web page http://www.omg.org, under Documents & Specifications, Report a Bug/Issue. Contents Preface . v 1. XMI Overview . 1-1 1.1 Introduction . 1-1 1.2 XMI and the MOF . 1-2 1.2.1 An Overview of the MOF . 1-2 1.2.2 The Relationship between XMI and MOF . 1-6 1.2.3 The Relationship between XMI, MOF and UML 1-6 1.3 XMI and XML . 1-7 1.3.1 The Roots of XML . 1-7 1.3.2 Benefits of using XML . 1-7 1.3.3 XML and the Computer Industry . 1-8 1.3.4 How XML Works . 1-8 1.3.5 XML and the OMG. 1-11 1.3.6 New XML Technologies. 1-11 2. Usage Scenarios . 2-1 2.1 Purpose. 2-1 2.2 Combining Tools in a Heterogeneous Environment . 2-1 2.3 Co-operating with Common Metamodel Definitions . 2-2 2.4 Work Environment . 2-3 2.4.1 Working in a Distributed and Intermittently Connected Environment . 2-3 2.5 Promoting Design Patterns and Reuse . 2-3 3. XMI DTD Design Principles . 3-1 3.1 Purpose. 3-1 January 2002 OMG - XML Metadata Interchange (XMI), v1.2 i Contents 3.2 Use of XML DTDs. 3-2 3.2.1 XML Validation of XMI Documents . 3-3 3.2.2 Requirements for XMI DTDs . 3-3 3.3 Basic Principles . 3-3 3.3.1 Required XML Declarations. 3-3 3.3.2 Metamodel Class Representation . 3-4 3.3.3 Metamodel Extension Mechanism . 3-4 3.4 XMI DTD and Document Structure . 3-5 3.5 Necessary XMI DTD Declarations. 3-6 3.5.1 Necessary XMI Attributes . 3-6 3.5.2 Common XMI Elements. 3-8 3.5.3 XMI . 3-9 3.5.4 XMI.header. 3-10 3.5.5 XMI.content . 3-10 3.5.6 XMI.extensions. 3-10 3.5.7 XMI.extension . 3-10 3.5.8 XMI.documentation . 3-11 3.5.9 XMI.model . 3-11 3.5.10 XMI.metamodel . 3-12 3.5.11 XMI.metametamodel . 3-12 3.5.12 XMI.import. 3-12 3.5.13 XMI.difference . 3-13 3.5.14 XMI.delete . 3-13 3.5.15 XMI.add . 3-13 3.5.16 XMI.replace . 3-14 3.5.17 XMI.reference . 3-14 3.6 Metamodel Class Specification . 3-14 3.6.1 Namespace Qualified XML Element Names . 3-14 3.6.2 Metamodel Multiplicities . 3-16 3.6.3 Class Specification . 3-16 3.6.4 Inheritance Specification . 3-16 3.6.5 Attribute Specification . 3-17 3.6.6 Association Specification . 3-19 3.6.7 Containment Specification . 3-19 3.7 Transmitting Incomplete Metadata. 3-20 3.7.1 Interchange of Model Fragments . 3-20 3.7.2 XMI Encoding . 3-20 3.7.3 Example . 3-20 3.8 Linking. 3-21 3.8.1 Design Principles . 3-21 ii OMG - XML Metadata Interchange (XMI), v1.2 January 2002 Contents 3.8.2 Linking . 3-21 3.8.3 Example from UML . 3-22 3.8.4 XMI.reference . 3-24 3.9 Transmitting Metadata Differences . 3-24 3.9.1 Definitions . 3-24 3.9.2 Differences . 3-25 3.9.3 XMI Encoding . 3-25 3.9.4 Example . 3-26 3.10 Document Exchange with Multiple Tools . 3-27 3.10.1 Definitions . 3-27 3.10.2 Procedures . 3-28 3.10.3 Example . 3-29 3.11 General Datatype Mechanism . 3-30 4. XML DTD Production . 4-1 4.1 Purpose. 4-1 4.2 DTD Syntax Approaches . 4-2 4.2.1 DTD without entities . 4-2 4.2.2 DTD with class-level entities . 4-3 4.2.3 DTD with multi-level entities . 4-3 4.3 Rule Set 1: Simple DTD. 4-4 4.3.1 EBNF . 4-4 4.4 Fixed DTD Elements . 4-13 5. XML Generation Principles . 5-1 5.1 Purpose. 5-1 5.2 Introduction . 5-1 5.3 Two Model Sources . 5-2 5.3.1 Production by Object Containment. 5-2 5.3.2 MOF’s Role in XML Production . 5-8 5.3.3 Production by Package Extent . 5-8 5.4 Distinctions between Approaches . 5-12 5.4.1 Distinctions between Approaches in Certain Situations . 5-12 5.4.2 External Links . 5-13 5.4.3 Links not Represented by References. 5-13 5.4.4 Classifier-level Attributes . 5-13 5.4.5 Standard Elements . 5-14 6. XML Document Production . 6-1 6.1 Introduction . 6-1 January 2002 OMG - XMIL Metadata Interchange (XMI), v1.2 iii Contents 6.2 ENBF Rules Representation. 6-1 Appendix A - UML DTD. A-1 Appendix B - MOF DTD. B-1 Appendix C - Example Model Encodings . C-1 Appendix D - References. D-1 Appendix E - Compatibility and Conformance. E-1 Index. ..