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[[OCL Expressions|'''OCL expression''']] must be without side effects. It is a query language and as such it is not expected to change data as the language is applied. In MDriven we do however want to change data when appropriate – so we use the exact same syntax as OCL in something we call [[EAL – ExtendedActionLanguage.|'''EAL – ExtendedActionLanguage.''']]
 
[[OCL Expressions|'''OCL expression''']] must be without side effects. It is a query language and as such it is not expected to change data as the language is applied. In MDriven we do however want to change data when appropriate – so we use the exact same syntax as OCL in something we call [[EAL – ExtendedActionLanguage.|'''EAL – ExtendedActionLanguage.''']]
  
[[OCLps|'''OCLps''']]
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==== [[OCLps|'''OCLps''']] ====
  
[[Seeking the database with OCLps|'''Seeking the database with OCLps''']]
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==== [[Seeking the database with OCLps|'''Seeking the database with OCLps''']] ====
  
[[OCLOperators|'''OCLOperators''']]
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==== [[OCLOperators|'''OCLOperators''']] ====
  
[[Certain important constructs|'''Certain important constructs''']]
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==== [[Certain important constructs|'''Certain important constructs''']] ====
  
'''[[Methods]]'''
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==== '''[[Methods]]''' ====
 +
More articles:
  
More articles:
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==== [[Unique constraints on 1 to 1 links]] ====
  
[[Unique constraints on 1 to 1 links]]
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==== [[GuardConstraints]] ====
  
[[GuardConstraints]]
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==== [[ClassFromString]] ====
  
[[ClassFromString]]
 
 
====[[Understanding OCL with reference to SQL]]====
 
====[[Understanding OCL with reference to SQL]]====
[[Custom types and custom operations in OCL]]
 
  
[[A few words on linq]]
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==== [[Custom types and custom operations in OCL]] ====
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==== [[A few words on linq]] ====
  
'''[[OCL by example]]'''
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==== '''[[OCL by example]]''' ====
 
[[Category:OCL]]
 
[[Category:OCL]]
 
[[Category:Discovery]]
 
[[Category:Discovery]]

Revision as of 09:57, 31 October 2019

What is Object Constraint Language

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. Initially, OCL was only a formal specification language extension to UML. OCL may now be used with any Meta-Object Facility (MOF) Object Management Group (OMG) meta-model, including UML. 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.

Learn more with ☛ OCL Video Tutorials

Different ways MDriven relies on OCL

  • As constraint definition on a class
  • As description of derivation rule on derived attributes
  • As description of derivation of derived associations
  • As ViewModel columns and Nesting definitions
  • As definitions for Visible and Enable state for ViewModel columns
  • As expression of style information on ViewModel columns
  • As expression for object presentation on classes
  • Action Enable expression
  • State machine Guards

MDriven relies heavily on OCL and it is a very powerful tool to describe constraints, actions and transformations in your model.

OCL expression must be without side effects. It is a query language and as such it is not expected to change data as the language is applied. In MDriven we do however want to change data when appropriate – so we use the exact same syntax as OCL in something we call EAL – ExtendedActionLanguage.

OCLps

Seeking the database with OCLps

OCLOperators

Certain important constructs

Methods

More articles:

Unique constraints on 1 to 1 links

GuardConstraints

ClassFromString

Understanding OCL with reference to SQL

Custom types and custom operations in OCL

A few words on linq

OCL by example