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

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 <[email protected]> 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
> > >>
> > >>
> > >
> > >
> >
>
>  
>