Pdf a formal language which is used to describe expressions on unified modelling language. The ocl file stores some kind of data stored in object constraint language. Warmer, kleppe, selic, gorman,yong he, amyot, brugge and dutoit, bultan, lings, lieber. Object constraint language ocl part of the uml specification. The unified modeling language uml includes a textual language called object constraint language ocl. Extracting umlocl integrity constraints and derived types. 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. What links here related changes upload file special pages permanent link page. Object constraint language ocl ocl is a formal language used to describe expressions on uml models. Founded in 1989, omg standards are driven by vendors, endusers, academic institutions and government agencies.
Object constraint language specification 6 this chapter introduces and defines the object constraint language ocl, a formal language to express sideeffectfree constraints. The object constraint language the ocl is used to specify constraints on objects in the uml. 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. It is a wellknown fact that due to the lack of familiarity with ocl, practitioners and even researcher to some extent are reluctant in using ocl. Ocl is strongly typed language welldefined ocl expressions have to satisfy type rules e. Object constraint language ocl cheat sheet ocl syntax. Ocl fills in this gap by providing a simple, implementation format independent language for expressing predicates. For years, researchers in software product lines splsexplored generalizations. The object constraint language ocl appeared as an e. 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. The object constraint language ocl started as a com. Copies of specifications, available in postscript and pdf format, may be. The ocl file extension is associated with the object constraint language a declarative language for describing rules that apply to unified modeling language uml models, developed by ibm the ocl file stores some kind of data stored in object constraint language. Every constraint is bound to a specific type class, association class, interface in the uml model its context.
Please report any encountered bugs using the ticket system. Getting your models ready for mda by jos warmer and anneke kleppe jos was one of the main creators of the ocl. Dec 15, 2016 the unified modeling language uml includes a textual language called object constraint language ocl. The object constraint language is a precise text language that provides constraint and object query expressions on any mof model or metamodel that cannot otherwise be expressed by diagrammatic notation. Ocl allows users to navigate class diagrams, to formulate queries, and to restrict class diagrams with integrity constraints. 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. Object constraint language object management group. Useocl use ocl 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. Quiting use without saving the current layount will create the file. Therefore, each ocl expression can be read and evaluated lefttoright. Also, there is generally no substantial support for constraints written in the object constraint language ocl. Unease about ocls complexity transcends mde where a simple constraint language for uml class diagrams is needed. Uml uses a variety of diagrams for describing both static and dynamic aspects of a system.
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. Ocl is part of unified modeling language uml and it plays an important role in the analysis phase of the software lifecycle. Object constraint language this specification defines the object constraint language ocl, version 2. The object constraint language ocl is a declarative language describing rules applying to. This paper reflects on a number of aspects of the syntax and semantics of the ocl, and makes proposals for clarification or extension.
If you are interested in contributing to eclipse ocl, we recommend you to use the oomph setup files, which will prepare the ide and the workspace with all requried sources. Zu einem umlmodell kann es viele oclbedingungen geben. Ob diese in einer oder mehreren dateien verwaltet werden, ist im prinzip. The object constraint language ocl is an expression language that.
He is an active member of the unified modeling language uml revision task force, which defined the revisions in the uml 2. A librarybased approach to translating ocl constraints to. 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. The object constraint language ocl is a specification language which. Case study of object constraints language ocl tools. Aug 23, 2018 the object constraint language ocl is an omg standard for specifying constraints on, amongst others, metamodels. Object constraint language formal060501 object management.
We present an approach for the validation of uml models and ocl constraints that is. It can be used to express additional constraints on uml models that cannot or are difficult to be expressed graphically. Ocl object constraint language part of the uml standard. Parts of the syntax seem to have been influenced by smalltalk disclaimer opinions expressed here may be out of date. An important rule is that an ocl expression always evaluates to a specific object of a specific type. This specification defines the object constraint language ocl, version 2. Initially, ocl was merely a formal specification language extension for uml. The object constraint language ocl, which forms part of the uml set of modeling notations, is a precise, textual language for expressing constraints that cannot be shown diagrammatically in uml. The object constraint language second edition written by anneke kleppe and jos warmer, explains in no time, how to complete your platform independent models, with business and query language. Properties can be combined to make more complicated expressi ons. This page is about the meanings of the acronymabbreviationshorthand ocl in the computing field in general and in the software terminology in particular. One can use ocl to express, for example, requirement that a specification should contain an even number of commands example 2. If you have oomph installed you simply have to import the ocl and qvto development setups from the catalog.
Ocl was first developed in 1995 inside ibm as an evolution of an expression language in the syntropy method 26. There are certain rules that cannot be expressed using a schema language alone. The ocl file extension is associated with the object constraint language a declarative language for describing rules that apply to unified modeling language uml models, developed by ibm. Parts of the syntax seem to have been influenced by smalltalk. This site is like a library, you could find million book here by using search box in the header. Ocl expressions typically specify invariant conditions that must hold for the system being modeled. Each ocl expression is the direct translation at the conceptual level of either one of the database constraints e. Pdf object constraint language ocl famma faissal and. Object constraint language formal language for expressing constraints over a set of objects and their attributes part of the uml standard used to write constraints that cannot otherwise be expressed in a diagram declarative no side effects no control flow based on sets and multi sets.
Ocl the object constraint language based on presentations from. A pratical application of the object constraint language ocl. Code generation is supported for both uml model and ocl files. Object constraint language inria book pdf free download link or read online here in pdf. The object constraint language the ocl is used to specify constraints on objects in. Context object may be denoted within the expression using the keyword self. Documentation is available via wikitext as a pdf monolith, html files or eclipse help. The classic core ocl component provides the following capabilities to support ocl integration. Modelbased assertion dl df fll warmer and kleppe define a constraint as follows.
Jos warmer is the primary author of the ocl standard. Down closedfixed 315655 use xtext editor closedfixed 315656 support complete ocl closedfixed 316192 aliases used in oclinecore constraints are. Natural language text is used to explain the background and motivation of the models. The context objects may be denoted within the expression using the keyword self. The documentation includes examples and tutorials which remain valid after a refresh for mars. Mar 21, 2012 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 specifying detailed aspects of a system design. Reflections on the object constraint language pdf ali hamie, franco civello, john howse, stuart kent and richard mitchell the object constraint language ocl, which forms part of the uml set of modeling notations, is a precise, textual language for expressing constraints that cannot be shown diagrammatically in uml. Previously he was a member of the uml core team, where he was responsible for the development of the 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 specification version 1. About the object constraint language specification version 2. 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. Object constraint language inria book pdf free download link book now. Ocl was introduced as a part of uml in 1997 as a business modeling language by ibm. Constraint invariant is a boolean ocl expression, evaluates to truefalse. Context links ocl constraint to specific type class, association class, interface, etc. In view of this, ibm has proposed the object constraint language ocl as the uml standard specification language. 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.
Does anyone know good object constraint language ocl. Ocl may now be used with any meta object facility mof object management group omg metamodel, including uml. Ocl object constraint language masarykova univerzita. The object constraint language ocl is a declarative language for describing rules that apply to unified modeling language uml models developed at ibm and now part of the uml standard. A constraint is a restriction on one or more values of part of an objectoriented model or system.
Object constraint language language ocl a formal specification language extension to uml. Ocl as specification language for object constraints. The object constraint language ocl is a textual, formal specification language for specifying the semantics of uml models. The object constraint language ocl is frequently used to specify additional constraints on models, in addition, to the ones enforced by semantics of the models. Defines apis for parsing and evaluating ocl constraints and queries on ecore or uml models. Introduction the object constraint language the ocl is used to specify constraints on objects in the uml. The object constraint language ocl is a declarative language for describing rules that apply to unified modeling language uml models developed at ibm. These predefined value types are independent of any object model and part of the definition of ocl. Introduction to the object constraint language tutorial.
Sql for relational database management systems or xpathxqueries for xml documents. An adaptable ocl engine for validating models in different tool. This prototype shows how ocl rules embedded in the nist 1500 models can be. Using ocl, for example, one can specify the behavior of a class by writing, among other things, class invariants and. Ocl is a typed language, so that each ocl expression has a type. Pdf 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. By using ocl, constraints and queries can be speci ed in a formal yet. The object constraint language ocl started as a com plement of the uml notation with the goal to overcome the limitations of. All books are in clear copy here, and all files are secure so dont worry about it. Object constraint language oclhas not gone unscathed 2, 9, 10, 12, 26, 52. Contents this chapter contains the following topics. 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. They also specify queries over objects described in a model.
However, in many cases, a graphical model like a class diagram, is not enough for a precise and unambiguous. Hol ocl is an interactive proof environment for the object constraint language ocl. However, use of the ocl specified by iso iec 19501. Object constraint language article about object constraint. Sincethen, oclhasbecomea keycomponentofanymodeldrivenengineering mde techniqueasthe default language. Object constraint language ocl pure expression language. Object constraint modelbased assertion dldf fllwarmer and kleppe define a constraint as follows. Eclipse ocl is an implementation of the object constraint language ocl omg standard for emfbased models. It is implemented as a shallow embedding of ocl into the higherorder logic hol instance of the interactive theorem prover isabelle. Ocl specifications are commonly referred to as constraints. 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. The object constraint language ocl started as a complementoftheumlnotationwiththegoaltoovercomethelimitationsof umlandingeneral,anygraphicalnotation intermsofpreciselyspecifyingdetailedaspectsofasystemdesign. An interactive tool for specifying, validating and. It is a bad practice to use this file, especially when various diagrams are to be build.