Praise for the object constraint language, second editionmda promises a revolution in the way we develop software. The object constraint language shows that with simple, elegant ocl statements, a uml design can be made more logically robust and easy to understand. Ocl basics ocl is used to specify invariants of objects and pre and post conditions of operations. Ocl was first developed in 1995 inside ibm as an evolution of an expression language in the syntropy method 26. Queries sideeffectfree operations can be used in ocl. Object constraint language specification 6 this chapter introduces and defines the object constraint language ocl, a formal language to express sideeffectfree constraints. Object constraint language object management group. Object modeling with the ocl the rationale behind the.
A constraint is a restriction on one or more values of a model or system. Taken from the object constraint language by warmer and. Ocl the object constraint language based on presentations from. Getting your models ready for mda by jos warmer and anneke kleppe jos was one of the main creators of the ocl. Use is a system for the specification and validation of information systems based on a subset of the unified modeling language uml and the object constraint language ocl. Im trying to find an ocl excpression calculator, but im not sure how to get the sum of the attributes of a collection i have a class customer and a class orders. Does anyone know good object constraint language ocl. The object constraint language ocl started as a complement of the uml notation with the goal to overcome the limitations of uml and in general, any graphical notation in terms of precisely. Object constraint language how is object constraint language abbreviated. In a class model, an operation or method is defined to be sideeffectfree if the isquery attribute of the. We present an approach for the validation of uml models and ocl constraints that is.
Introduction the object constraint language the ocl is used to specify constraints on objects in the uml. Like an oopl, an ocl expression involves operators operating on objects. This process is experimental and the keywords may be updated as the learning algorithm improves. This book contains key contributions to the development of ocl. Contents this chapter contains the following topics. A constraint is an expression that evaluate to true or false as a query language queries are expressions that evaluate to a value true, 7 false and other values can be used to define new attributes and operations ocl expressions are always associated with a uml model. Ocl is a textual language to describe constraints the constraint language used in uml models as well as the uml metamodel ocl expressions are always bound to a uml model ocl expressions can be bound to any model element in uml. Ocl a formal specification language extension to uml. 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. Ocl was introduced as a part of uml in 1997 as a business modeling language by ibm. Ocl object constraint language part of the uml standard. Defines apis for parsing and evaluating ocl constraints and queries on ecore or uml models. Warmer, kleppe, selic, gorman,yong he, amyot, brugge and dutoit, bultan, lings, lieber.
Object constraint language article about object constraint. Within uml, ocl is the standard for specifying expressions that add vital information to objectoriented models and other objectmodeling artifacts. Please report any encountered bugs using the ticket system. Users of the unified modeling language and other languages can use ocl to specify constraints and other expressions attached to their models. Defines apis for parsing and evaluating ocl constraints and queries on. Initially, ocl was merely a formal specification language extension for uml. Notes in computer science, 1999, volume 17431999, 793. The object constraint language ocl appeared as an effort to overcome the limitations of uml when it comes to precisely specifying detailed aspects of a system design.
Ever since its inception, the actual use of ocl in the industry has been almost negligible, even amongst the business application development community, for which it was specifically created. Ocl conformance rules are applied to validate an element, relationship or attribute against any defined constraints in the object constraint language ocl. Object constraint language inria book pdf free download link book now. Object constraint language class soil derivation rule real type collection operation these keywords were added by machine and not by the authors. All of the power of logic and discrete mathematics is available. A pratical application of the object constraint language ocl. Stuart kent, andy evans and bernhard rumpe, uml semantics faq, object oriented technology ecoop99 workshop reader, lecture nstuart kent, andy evans et. A constraint is a restriction on one or more values a constraint is a restriction on one or more values of part of an object oriented model or system. Overview this document introduces and defines the object constraint language ocl, a formal language to express side effectfree constraints. Therefore, each ocl expression can be read and evaluated lefttoright. Object constraint language language ocl a formal specification language extension to uml. Ocl attribute accesses navigate through uml class diagram. The object constraint language is a declarative language for describing rules that apply to unified modeling language models developed at ibm. Ocl is a descendant of syntropy, a secondgeneration object oriented analysis and design method.
Object constraint language ocl, is a formal language. However, only ascii characters rather than convent ional mathematical notation should be used. Object constraint language inria book pdf free download link or read online here in pdf. Object constraint language ocl object constraint language. Ocl is a typed, declarative and sideeffect free specification language. Ocl object constraint language select, use sum for attribute. The object constraint language ocl appeared as an effort to overcome the. Pdf case study of object constraints language ocl tools. Stack overflow for teams is a private, secure spot for you and your coworkers to find and share information. This page is about the meanings of the acronymabbreviationshorthand ocl in the computing field in general and in the software terminology in particular. Object constraint language ocl cheat sheet ocl syntax. Within uml, ocl is the standard for specifying expressions that add vital information to object oriented models and other object modeling artifacts.
Copies of specifications, available in postscript and pdf format. The object constraint language ocl is a language that enables one to describe expressions and constraints on objectoriented models and other object modelling artefacts. The object constraint language, second edition, utilizes a case study to show how to exercise these compact but powerful expressions for maximum effect. Ocl as specification language for object constraints. An important rule is that an ocl expression always evaluates to a specific object of a specific type. Ocl may now be used with any metaobject facility mof object management group omg metamodel, including uml. The object constraint language ocl started as a com. You may be surprised to learn that the ability to model such constraints is now built into the unified modeling language uml v. All books are in clear copy here, and all files are secure so dont worry about it. Introduction to the object constraint language tutorial. Mar 21, 2012 the object constraint language ocl appeared as an effort to overcome the limitations of uml when it comes to precisely specifying detailed aspects of a system design. Object constraint language formal060501 object management. About the object constraint language specification version 2.
Ocl is a textual language to describe constraints the constraint language used in uml models as well as the uml metamodel ocl expressions are always bound to a. Ocl expressions typically specify invariant conditions that must hold for the system being modeled. Explains why ocl is critical to mdaand why uml alone is not enough. Properties can be combined to make more complicated expressi ons. Natural language text is used to explain the background and motivation of the models. However, in many cases, a graphical model like a class diagram, is not enough for a precise and unambiguous. Ocl expressions use vocabulary of uml class diagram. Eclipse ocl is an implementation of the object constraint language ocl omg standard for emfbased models. They also specify queries over objects described in a model. I want to have the sum of all orders of a particular year saved in the customer class, attribute revenue. The object constraint language is a precise text language that provides constraint and object query expressions on an objectoriented model that cannot otherwise be expressed by diagrammatic notation.
Parts of the syntax seem to have been influenced by smalltalk disclaimer opinions expressed here may be out of date. Object constraint language what is object constraint language. Metaobject facility mof object constraint language ocl. As part of the uml standard ocl has been adopted by both professionals in industry and by academic researchers and is one of the most widely used languages for expressing objectoriented system properties. The classic core ocl component provides the following capabilities to support ocl integration. Ocl overview a formal notation for users of uml to add more prec ision to their specifications.
A constraint is a restriction on one or more values a constraint is a restriction on one or more values of part of an objectoriented model or system. Object constraint language ocl ocl is a formal language used to describe expressions on uml models. Aug 31, 2016 the object constraint language is a declarative language for describing rules that apply to unified modeling language models developed at ibm and now part of the uml standard. You can add ocl constraints to any element, relationship or attribute in enterprise. Previously he was a member of the uml core team, where he was responsible for the development of the object constraint language ocl. Object constraint modelbased assertion dldf fllwarmer and kleppe define a constraint as follows.
This book is essential reading for anyone intending to adopt mda technology. The ocl is a standard query language, which is part of the unified modelling language uml set by the object management group omg. The object constraint language is a precise text language that provides constraint and object query expressions on an object oriented model that cannot otherwise be expressed by diagrammatic notation. Also, there is generally no substantial support for constraints written in the object constraint language ocl. Overview this document introduces and defines the object constraint language ocl, a formal language to express side effect free constraints. Object constraint language how is object constraint. This specification defines the object constraint language ocl, version 2. Ocl supplements uml by providing expressions that have. After obtaining a result, one can always apply another property to the result to get a new result value. Ocl is a typed language, so that each ocl expression has a type. Uml uses a variety of diagrams for describing both static and dynamic aspects of a system.
605 750 1520 695 362 891 893 1157 932 244 1298 1201 801 1097 479 1168 722 320 1498 1167 622 1448 837 159 743 559 1332 194 39 319 363 1544 1496 1281 556 1473 211 240 955 771 1165 251