Hi and hrmmm,
What if user group was changed? groupMapper.toEntity(user.getGroup(),
userDto.getGroup()); This would then operate on stale data unless you fetch
and send in correct group. And managing new groups is easy for me I think,
I would call the method using groupMapper.toEntity(new Group(),
userDto.getGroup());
I would much prefer all three methods to be non protected. Then I could
create my helper something along the lines of this:
I did not test this very well but unless I thought wrong completely it
would be a one time thing to implement. But using mappers from mappers are
hard because if the relationship is declared in both ways you can get
circular references. Anyways here's my helper I theorycrafted together:
Group g = fetch (new Group(), user.getGroup(), groupMapper);
public <Entity, Dto> Entity fetch(Entity entity, Dto dto,
SimpleQueryInOutMapperBase<Entity, Dto> entityMapper){
Object pk = entityMapper.getPrimaryKey(dto);
Entity foundEntity = (Entity) entityManager.find(entity.getClass(),
pk);
if (foundEntity == null) {
foundEntity = entity;
}
return entityMapper.toEntity(foundEntity, dto);
}
One could always create their own base class overriding the protected
methods and adding that fetch helper I guess...
cheers
On 13 June 2014 12:54, Thomas Hug <[email protected]> wrote:
> Hey Karl
>
> Sorry missed your mail indeed - it's probably time I subscribe to the user
> mailing list too :-)
>
> You can still chain those mappers together, but I agree the casting and
> wiring is clunky. As options I see:
> - we add a public E toEntity(Dto dto) back which basically does the same as
> mapParameter now (just hides the casting) for new entities
> - we make the E toEntity(Entity e, Dto dto) public as well, so it's quite
> easy to chain mapper calls for updates
>
> groupMapper.toEntity(user.getGroup(), userDto.getGroup());
>
> You will still have to have some conditionals to see which one to call,
> also depends on your data model (required relations, lazy or eager fetch).
> How does that look? Better ideas?
>
>
>
> On Fri, Jun 13, 2014 at 8:42 AM, Karl Kildén <[email protected]>
> wrote:
>
> > I wrote a response to the users list but not sure it came through. It
> kinda
> > belongs in this thread so here it goes.
> >
> >
> > So I ran into issues with the DTO mapper api and voiced my concerns in
> irc.
> > I saw this discussion and now I am trying the solution present in the
> > current SNAPSHOT. However I have one comment / question:
> >
> > What if my Entity has a relationship to another Entity?
> >
> > Like this:
> >
> > public class User extends BaseAuditEntity {
> >
> > @Column
> > private String name;
> >
> > @Column
> > @ManyToOne
> > @JoinColumn(name="group_id")
> > private Group group;
> >
> > This means my userDTO may come with a GroupDTO and how do I map that
> > relationship? Or to explain by code please fill in the question marks
> below
> > ;) or if you feel my implementation is weird then I would gladly accept
> > comments on that too. But the way I see it I need to @Inject the
> > GroupMapper, use the EntityManager to find the Group then call
> > groupMapper.toEntity and then I think to myself that the API is worse now
> > because before I could call groupMapper.toEntity with only a dto
> argument.
> > At that point you had to use the entitymanager anyways to find "yourself"
> > and that feels clean compared to find your entities you form
> relationships
> > with.
> >
> > @Override
> > protected User toEntity(final User user, final UserDTO userDTO) {
> > MapperUtil.toAuditEntity(user, userDTO);
> > user.setName(userDTO.getName());
> > user.setEmail(userDTO.getEmail());
> > user.setLocale(userDTO.getLocale());
> > user.setGroup(*?????*);
> > return user;
> > }
> >
> > Cheers / Karl
> >
> >
> > On 17 May 2014 16:40, Romain Manni-Bucau <[email protected]> wrote:
> >
> > > Yep, missed it.
> > >
> > > Works for me. Maybe the name should be closer to other methods,
> > > mapKey? But whatever you choose as name this solution works :).
> > >
> > >
> > > Romain Manni-Bucau
> > > Twitter: @rmannibucau
> > > Blog: http://rmannibucau.wordpress.com/
> > > LinkedIn: http://fr.linkedin.com/in/rmannibucau
> > > Github: https://github.com/rmannibucau
> > >
> > >
> > > 2014-05-17 15:54 GMT+02:00 Thomas Hug <[email protected]>:
> > > > It's the PK, not the Entity ;) In SimpleQueryInOutMapperBase, it
> could
> > be
> > > > something like
> > > >
> > > > @Inject
> > > > private QueryInvocationContext context;
> > > >
> > > > protected abstract Object getPrimaryKey(Dto dto);
> > > >
> > > > protected E findEntity(Object pk)
> > > > {
> > > > return (E)
> > context.getEntityManager().find(context.getEntityClass(),
> > > > pk);
> > > > }
> > > >
> > > > @Override
> > > > public Object mapParameter(final Object parameter)
> > > > {
> > > > Object pk = getPrimaryKey((Dto) parameter);
> > > > if (pk != null)
> > > > {
> > > > E entity = findEntity(pk);
> > > > return toEntity(entity, (Dto) parameter);
> > > > }
> > > > return toEntity(newEntity(), (Dto) parameter);
> > > > }
> > > >
> > > >
> > > > On Sat, May 17, 2014 at 1:57 PM, Romain Manni-Bucau
> > > > <[email protected]>wrote:
> > > >
> > > >> would work while return is <E> and not Object ;)
> > > >>
> > > >>
> > > >> Romain Manni-Bucau
> > > >> Twitter: @rmannibucau
> > > >> Blog: http://rmannibucau.wordpress.com/
> > > >> LinkedIn: http://fr.linkedin.com/in/rmannibucau
> > > >> Github: https://github.com/rmannibucau
> > > >>
> > > >>
> > > >> 2014-05-17 11:47 GMT+02:00 Thomas Hug <[email protected]>:
> > > >> > Or a protected abstract Object getPrimaryKey(Dto dto). We can get
> > the
> > > EM
> > > >> > over an injected QueryInvocationContext.
> > > >> >
> > > >> >
> > > >> > On Thu, May 15, 2014 at 9:06 PM, Romain Manni-Bucau
> > > >> > <[email protected]>wrote:
> > > >> >
> > > >> >> I think a protected findEntity(id) in the mapper can be enough.
> > > >> >>
> > > >> >>
> > > >> >> Romain Manni-Bucau
> > > >> >> Twitter: @rmannibucau
> > > >> >> Blog: http://rmannibucau.wordpress.com/
> > > >> >> LinkedIn: http://fr.linkedin.com/in/rmannibucau
> > > >> >> Github: https://github.com/rmannibucau
> > > >> >>
> > > >> >>
> > > >> >> 2014-05-07 22:29 GMT+02:00 Thomas Hug <[email protected]>:
> > > >> >> > Hi Romain,
> > > >> >> > See your point. But if we only get the DTO - with what would we
> > > call
> > > >> the
> > > >> >> > find? Could even be that the PK is a DTO or encoded / encrypted
> > and
> > > >> needs
> > > >> >> > to go through the mapper first. Maybe we can provide some
> > > convenience
> > > >> >> > methods in the base mapper?
> > > >> >> >
> > > >> >> >
> > > >> >> > On Tue, May 6, 2014 at 7:41 PM, Romain Manni-Bucau <
> > > >> >> [email protected]>wrote:
> > > >> >> >
> > > >> >> >> Hi guys,
> > > >> >> >>
> > > >> >> >> DTO feature is awesome but doesn't work in update mode since
> > isNew
> > > >> >> >> doesn't use a managed entity.
> > > >> >> >>
> > > >> >> >> When using a mapper we should call find and pass it to the
> > mapper
> > > (or
> > > >> >> >> create a new unmanaged entity if not found). So mapper
> signature
> > > >> >> >> should be Entity toEntity(Entity, DTO) no?
> > > >> >> >>
> > > >> >> >> Otherwise users need to do the find in the mapper...almost
> > > eveytime.
> > > >> >> >>
> > > >> >> >> wdyt?
> > > >> >> >>
> > > >> >> >>
> > > >> >> >> Romain Manni-Bucau
> > > >> >> >> Twitter: @rmannibucau
> > > >> >> >> Blog: http://rmannibucau.wordpress.com/
> > > >> >> >> LinkedIn: http://fr.linkedin.com/in/rmannibucau
> > > >> >> >> Github: https://github.com/rmannibucau
> > > >> >> >>
> > > >> >>
> > > >>
> > >
> >
>
