Re: How to identify if a concept should be represented as a entity or as a value obj

Nice post thanks.



--- In [email protected], Giacomo Tesio <giacomo@...> wrote:
>
> I have no value object holding pointers to any entity.
> 
> Shared identifiers
> <http://epic.tesio.it/doc/manual/shared_identifiers.html> proved
> very well when adressing the need of values that need to refer to an entity
> (see the "Decoupling Entities" section).
> 
> Indeed identifiers are values (thus I model them as value objects).
> 
> 
> Giacomo
> 
> On Mon, Feb 25, 2013 at 5:12 PM, sudarshan89 <sudarshan89@...> wrote:
> 
> > **
> >
> >
> > Point taken.
> >
> > Could we say that a Value object would never hold a reference to an entity
> > ?
> >
> > A Value Object would always be composed of other value objects ?
> >
> >
> > --- In [email protected], Giacomo Tesio wrote:
> > >
> > > I model entities after the expert's language, when he talks with his own
> > > peers he use a name to identify an entity while he describes value
> > objects.
> > >
> > > For example, in a financial application he could use the RIC or the ISIN
> > to
> > > identify an entity, but he doesn't identify a monetary amount.
> > >
> > >
> > > Giacomo
> > >
> > >
> > >
> > > On Mon, Feb 25, 2013 at 5:58 AM, Remy Fannader wrote:
> > >
> > > > **
> >
> > > >
> > > >
> > > > Entities have a life-cycle of their own while the life-cycle of VOs is
> > set
> > > > by their use.
> > > > That means that entities can identified independently and accessed by
> > > > unknown applications.
> > > >
> > > >
> > http://caminao.wordpress.com/how-to-represent-objects-and-activities/identities-2/identities/
> > > > Remy.
> > > >
> > > > On 25 February 2013 06:46, sudarshan89 wrote:
> > > >
> > > >> **
> >
> > > >>
> > > >>
> > > >>
> > > >> I am trying to find out what question one must ask during the
> > modelling
> > > >> process to detect if a concept should be modeled as a entity or as a
> > value
> > > >> object.
> > > >>
> > > >> My current understanding is the below
> > > >>
> > > >> If in our domain a car engine can be swapped out and put in another
> > car
> > > >> then it has existence of its own (Aggregation) and hence cannot be a
> > Value
> > > >> Object ... However in our domain if the engine cannot be swapped out
> > and
> > > >> hence makes no sense without a car then it can be modeled as a Value
> > Object
> > > >> (Composition). Does this make any sense ?
> > > >>
> > > >> Please let me know what you think
> > > >>
> > > >> Thanks
> > > >>
> > > >>
> > > >
> > > >
> > >
> >
> >  
> >
>




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