XML Metadata Interchange
Encyclopedia
The XML Metadata Interchange (XMI) is an Object Management Group (OMG)
standard for exchanging metadata information via Extensible Markup Language (XML)
.
It can be used for any metadata whose metamodel can be expressed in Meta-Object Facility (MOF)
.
The most common use of XMI is as an interchange format for UML
models, although it can also be used for serialization of models of other languages (metamodels).
or SysML. For diagrams, the Diagram Interchange (DI, XMI[DI]) standard is used. At the moment there are several incompatibilities between different modeling tool vendor implementations of XMI, even between interchange of abstract model data. The usage of Diagram Interchange is almost nonexistent. Unfortunately this means exchanging files between UML
modeling tools using XMI is rarely possible.
One purpose of XML Metadata Interchange (XMI) is to enable easy interchange of metadata between UML-based modeling tools and MOF-based metadata repositories in distributed heterogeneous environments. XMI is also commonly used as the medium by which models are passed from modeling tools to software generation tools as part of model-driven engineering
.
The integration of these four standards into XMI allows tool developers of distributed systems to share object models and other metadata.
Several versions of XMI have been created: 1.0, 1.1, 1.2, 2.0 and 2.1. The 2.x versions are radically different from the 1.x series. The version 2.1.1 was issued in December 2007.
There are now other XML standards for representing metadata. One of the most recent is the Web Ontology Language (OWL)
(but ontologies are a very specialized kind of metadata, and OWL has no built-in support for most of the information represented in UML). OWL is built upon the Resource Description Framework (RDF)
.
XMI is now an international standard:
Object Management Group
Object Management Group is a consortium, originally aimed at setting standards for distributed object-oriented systems, and is now focused on modeling and model-based standards.- Overview :...
standard for exchanging metadata information via Extensible Markup Language (XML)
Extensible Markup Language
Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
.
It can be used for any metadata whose metamodel can be expressed in Meta-Object Facility (MOF)
Meta-Object Facility
The Meta-Object Facility is an Object Management Group standard for model-driven engineering. The official reference page may be found at OMG's website.- Overview :...
.
The most common use of XMI is as an interchange format for UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...
models, although it can also be used for serialization of models of other languages (metamodels).
Overview
In the OMG vision of modeling, data is split into abstract models and concrete models. The abstract models represent the semantic information, whereas the concrete models represent visual diagrams. Abstract models are instances of arbitrary MOF-based modeling languages such as UMLUnified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...
or SysML. For diagrams, the Diagram Interchange (DI, XMI[DI]) standard is used. At the moment there are several incompatibilities between different modeling tool vendor implementations of XMI, even between interchange of abstract model data. The usage of Diagram Interchange is almost nonexistent. Unfortunately this means exchanging files between UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...
modeling tools using XMI is rarely possible.
One purpose of XML Metadata Interchange (XMI) is to enable easy interchange of metadata between UML-based modeling tools and MOF-based metadata repositories in distributed heterogeneous environments. XMI is also commonly used as the medium by which models are passed from modeling tools to software generation tools as part of model-driven engineering
Model-driven engineering
Model-driven engineering is a software development methodology which focuses on creating and exploiting domain models , rather than on the computing concepts...
.
Integration of industry standards
XMI integrates four industry standards:- XMLXMLExtensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
– Extensible Markup Language, a W3C standard. - UMLUnified Modeling LanguageUnified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...
– Unified Modeling Language, an OMGObject Management GroupObject Management Group is a consortium, originally aimed at setting standards for distributed object-oriented systems, and is now focused on modeling and model-based standards.- Overview :...
modeling standard. - MOFMeta-Object FacilityThe Meta-Object Facility is an Object Management Group standard for model-driven engineering. The official reference page may be found at OMG's website.- Overview :...
– Meta Object Facility, an OMGObject Management GroupObject Management Group is a consortium, originally aimed at setting standards for distributed object-oriented systems, and is now focused on modeling and model-based standards.- Overview :...
language for specifying metamodels. - MOF – Mapping to XMI
The integration of these four standards into XMI allows tool developers of distributed systems to share object models and other metadata.
Several versions of XMI have been created: 1.0, 1.1, 1.2, 2.0 and 2.1. The 2.x versions are radically different from the 1.x series. The version 2.1.1 was issued in December 2007.
There are now other XML standards for representing metadata. One of the most recent is the Web Ontology Language (OWL)
Web Ontology Language
The Web Ontology Language is a family of knowledge representation languages for authoring ontologies.The languages are characterised by formal semantics and RDF/XML-based serializations for the Semantic Web...
(but ontologies are a very specialized kind of metadata, and OWL has no built-in support for most of the information represented in UML). OWL is built upon the Resource Description Framework (RDF)
Resource Description Framework
The Resource Description Framework is a family of World Wide Web Consortium specifications originally designed as a metadata data model...
.
XMI is now an international standard:
- ISOInternational Organization for StandardizationThe International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...
/IECInternational Electrotechnical CommissionThe International Electrotechnical Commission is a non-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies – collectively known as "electrotechnology"...
19503:2005 Information technology – XML Metadata Interchange (XMI)
See also
- Common Warehouse MetamodelCommon Warehouse MetamodelThe Common Warehouse Metamodel defines a specification for modeling metadata for relational, non-relational, multi-dimensional, and most other objects found in a data warehousing environment...
- Web Ontology LanguageWeb Ontology LanguageThe Web Ontology Language is a family of knowledge representation languages for authoring ontologies.The languages are characterised by formal semantics and RDF/XML-based serializations for the Semantic Web...
- Generic Modeling EnvironmentGeneric Modeling EnvironmentGeneric Modeling Environment is a model-integrated program synthesis tool for creating domain-specific models of large-scale systems. GME allows users to define new modeling languages using UML-based metamodels...
(GME) - Eclipse Modeling FrameworkEclipse Modeling FrameworkEclipse Modeling Framework is an Eclipse-based modeling framework and code generation facility for building tools and other applications based on a structured data model...
(EMF) - Domain Specific Language (DSL)
- Domain-specific modelling (DSM)
- Meta-modeling
- Meta-Object FacilityMeta-Object FacilityThe Meta-Object Facility is an Object Management Group standard for model-driven engineering. The official reference page may be found at OMG's website.- Overview :...
(MOF)
External links
- UML Diagram and corresponding XMI
- OMG XMI Specification
- the FullMoon XML Processor, a framework for processing XMI formats