Editing Object Constraint Language (section)

{{Short description|Declarative language}}
{{Update|date=April 2018}}

The '''Object Constraint Language''' ('''OCL''') is a [[declarative language]] describing rules applying to [[Unified Modeling Language]] (UML) models developed at [[IBM]] and is now part of the UML standard. Initially, OCL was merely a formal specification language extension for UML.<ref>Object Management Group (OMG); ''Object Constraint Language Specification'', Chapter 7 of ''OMG Unified Modeling Language Specification'', Version 1.3, March 2000 (first edition)</ref> OCL may now be used with any [[Meta-Object Facility]] (MOF) [[Object Management Group]] (OMG) [[meta-model]], including UML.<ref>Object Management Group (OMG); ''Object Constraint Language OMG Available Specification Version 2.0'', May 2006</ref> The Object Constraint Language is a precise text language that provides constraint and object query expressions on any MOF model or meta-model that cannot otherwise be expressed by diagrammatic notation. OCL is a key component of the new OMG standard recommendation for transforming models, the Queries/Views/Transformations ([[QVT]]) specification.