Ocl as specification language for object constraints dr. 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. Copies of specifications, available in postscript and pdf format. Contents this chapter contains the following topics. Object constraint modelbased assertion dldf fllwarmer and kleppe define a constraint as follows. 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. Plugin support is not available in the free community edition. The object constraint language shows that with simple, elegant ocl statements, a uml design can be made more logically robust and easy to understand. Therefore, we present a prototype tool, which analyzes the syntax. Context object may be denoted within the expression using the keyword self. Every constraint is bound to a specific type class, association class, interface in the uml model its context. A beta version of the ocltojava plugin, based on the dresden ocl toolkit, is currently available for free download. On the verification of umlocl class diagrams using.
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 help to create a precise and unambiguous specification in oo modelling. They also specify queries over objects described in a model. Object constraint language ocl object constraint 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. In this constraint, the self variable represents an arbitrary instance of the context type chosen to define the constraint, in this case paper. To enable reuse of variablesoperations over multiple ocl expressions one can use a constraint with the stereotype definition. Ocl is based on firstorder predicate logic but it uses a syntax similar to. Section 4 is about the adequate formal language for odp type descriptions. This specification defines the object constraint language ocl, version 2. Worlds best powerpoint templates crystalgraphics offers more powerpoint templates than anyone else in the world, with over 4 million to choose from. An introduction to the object constraint language ocl pdf.
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. The context objects may be denoted within the expression using the keyword self. Theyll give your presentations a professional, memorable appearance the kind of sophisticated look that todays audiences expect. 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. Also, there is generally no substantial support for constraints written in the object constraint language ocl. This book contains key contributions to the development of ocl. We present an approach for the validation of uml models and ocl constraints that is. Typed means that each ocl expression evaluates to a type either one of the prede. Ocl expressions typically specify invariant conditions that must hold for the system being modeled. Does anyone know good object constraint language ocl.
The object constraint language ocl started as a com. Initially, ocl was merely a formal specification language extension for uml. Object constraint language ocl ocl is a formal language used to describe expressions on uml models. Object constraint language ocl cheat sheet ocl syntax. The companies listed above have granted to the object management group, inc. Object constraint language inria book pdf free download link book now. Eclipse ocl is an implementation of the object constraint language ocl omg standard for emfbased models. 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. All books are in clear copy here, and all files are secure so dont worry about it. These predefined value types are independent of any object model and part of the definition of ocl.
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. You may be surprised to learn that the ability to model such constraints is now built into the unified modeling language uml v. Getting your models ready for mda by jos warmer and anneke kleppe jos was one of the main creators of the ocl. The object constraint language ocl is a declarative language describing rules applying to. On formalizing the uml object constraint language ocl citeseerx. Constraint invariant is a boolean ocl expression, evaluates to truefalse. Ocl is a typed language, so that each ocl expression has a type. Context links ocl constraint to specific type class, association class, interface, etc. Queries side effect free operations can be used in ocl expressions.
It can be used to express additional constraints on uml models that cannot be expressed, or are very difficult to express, with the graphical means provided by uml. A pdf version of this documentation is available at ocl 5. A constraint invariant is a boolean ocl expression evaluates to truefalse. Extracting umlocl integrity constraints and derived types. Each ocl expression is the direct translation at the conceptual level of either one of the database constraints e. Please update this article to reflect recent events or newly available information. Object constraint language can be used to specify constraints and other expressions attached to uml models or other models. Oclobject constraint language ocl is a textual language to define constraints ocl can specify queries, constraints and query operations ocl enables to add extra information to a uml model ocl is a standard extension to uml for, writing queries to access model elements and their values.
Object constraint language what is object constraint language. Ocl may now be used with any metaobject facility mof object management group omg metamodel, including uml. 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 modified versio n. All of omgs formal specifications may be downloaded without charge from our website. Ocl provides a modeling language that allows the behavior to be embedded within the structural meta. Ocl supplements uml by providing expressions that have neither the ambiguities of natural language nor the inherent difficulty of using. It provides an advanced ocl2 editor, a parser, an interpreter, and a codegenerator for java and sql. Ocl is a formal language that provides a way to specify uml constraints.
This class diagram is complemented with a set of ocl expressions that specify additional constraints for the model. The classic core ocl component provides the following capabilities to support ocl integration. Winner of the standing ovation award for best powerpoint templates from presentations magazine. A pdf version of this documentation is available at ocl 6. Object constraint language inria book pdf free download link or read online here in pdf. Please report any encountered bugs using the ticket system. On formalizing the uml object constraint language ocl.
Ocl a formal specification language extension to uml. By using ocl, constraints and queries can be specified in a formal yet comprehensible way. Pick an ocl constraint from the document, nd the diagram that gives its context, and. Object modeling with the ocl the rationale behind the object. It is a facility provided within the java programming language to test the correctness or. Translation find a translation for object constraint language in other languages. 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. 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. Taken from the object constraint language by warmer and. The object constraint language is a declarative language for describing rules that apply to unified modeling language models developed at ibm. 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 modified version.
The object constraint language ocl is the established language for the speci. Object constraint language object management group. One reason that it is not yet widely adopted in industry is the lack of proper and integrated tool support for ocl. Dresden oclallows to query arbitrary emfbased models. If c is a sequence, t is added as the last element of the new. The object constraint language ocl is a textual sublanguage of the unified modelling language uml. Ocl as specification language for object constraints. The let expression allows a variable to be used in one ocl expression. A pratical application of the object constraint language ocl. Queries sideeffectfree operations can be used in ocl. A metamodel facility for a family of uml constraint languages. Ocl object constraint language part of the uml standard. Defines apis for parsing and evaluating ocl constraints and queries on. Pdf case study of object constraints language ocl tools.
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