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  1. OMG Issue

UMLR — Why is a qualified association qualifier composed by a Property?

  • Key: UMLR-678
  • Status: open  
  • Source: Model Driven Solutions ( Ed Willink)
  • Summary:

    Consider the example in Fig 11.37 that is supported by the OCL navigation aBank.Person[accountNo].

    The nested Property is novel but avoids any bias as to whether the keys are actually part of e.g. a HashMap in Bank, or a linear search in Person. Seems good, but...

    How does aPerson discover their accountNo? Oops need to do a total content search of the Bank. Or provide duplicate Person::accountNo state with all the hazards that duplicate state entails.

    How can two qualified associations share the same qualifier? Can't it's Composed. Need yet more state duplication.

    If instead, Property::qualifier was not Composed, many qualified associations can refer to a Property that can be a regular unnested Property that can be navigated as aPerson.accountNo. Although the now regular Property appears hosted by the target, there is no prohibition on an implementation using a HashMap and locating it in the source, iff all required forms of access are supported.

  • Reported: UML 2.5 — Wed, 13 Apr 2016 21:37 GMT
  • Updated: Thu, 14 Apr 2016 19:31 GMT