[Catalyst] Instant CRUD with DBIC::Schema

[Zbigniew Lukasiak]

On Wed, Mar 12, 2008 at 3:25 PM, Peter Karman <peter at peknet.com> wrote:
>
>
>  On 03/12/2008 07:11 AM, Zbigniew Lukasiak wrote:
>
>  >>  I think it would be best  to be able to treat a CatalystX::CRUD
>  >>  application like any other catalyst application.  That is, minimal
>  >>  modification of $c->model('Foo') compared to an ordinary catalyst app
>  >>  so that the CRUD generator mostly gets out of the way.
>  >>
>  >
>  > Just thinking how this can be done - you need a
>  > CatalystX::CRUD::ModelAdaptor::XXXX and a model_adaptor_class config
>  > option for the CRUD controller.  Then in the controller methods you
>  > would do:
>  >
>  > $c->stash->{object} = $self->model_adaptor->fetch( @arg );
>  >
>  > instead of
>  >
>  > $c->stash->{object} = $c->model( $self->model_name )->fetch(@arg);
>  >
>  > and in places where you call methods on the object like: $obj->$method
>  > you could do again $self->model_adaptor->$method( $obj ).
>  >
>  > This way $c->stash->{object} could still be an unmodified object from
>  > the model and you would have your indirection layer needed to make the
>  > CRUD methods universal.
>
>  That seems to exchange one relative complexity for a different relative complexity. Not
>  sure how it makes it simpler.
>
>  Maybe this will help: I use my CX::CRUD::Model::Foo models in controllers other than my
>  CRUD controller. I assume CRUD isn't the *only* thing folks do in their apps. So I want to
>  be able to interact directly with the Foo model in any controller. If I must then
>  implement an extra model adapter in those other, non-CRUD controllers, I have added extra
>  complexity where before there was none.
>
>  Example:
>
>   package MyApp::Controller::Foo;
>
>   sub thing : Local {
>      my ($self, $c, $id) = @_;
>      my $thing = $c->model('Foo')->fetch( id => $id );
>      $c->stash->{object} = $thing;
>   }
>
>  nice and simple. $thing might be a CatalystX::CRUD::Object, but it should behave just like
>  whatever its delegate() is, thanks to the evil AUTOLOAD stuff. So from the perspective of
>  MyApp::Controller::Foo and whatever View ends up presenting 'object' in stash(), $thing is
>  a $thing.
>
>  What I hear you suggesting is that a ModelAdaptor would mean I'd have to do:
>
>   sub model_adaptor {
>     my ($self) = @_;
>     return $self->{_model_adaptor}; # instance of CatalystX::CRUD::ModelAdaptor::Foo
>   }
>
>   sub thing : Local {
>     my ($self, $c, $id) = @_;
>     my $thing = $self->model_adaptor->fetch( id => $id );
>     $c->stash->{object} = $thing;  # NOT a CatalystX::CRUD::Object
>   }
>
>  I guess it removes the delegate() and AUTOLOAD stuff. That would be simpler. But maybe we
>  could simplify it even further.
>
>  Your ModelAdaptor is essentially what a CX::CRUD::Model is already. If we moved the

It does the same thing - but in a different way - see below:

>  create/read/update/delete methods to CX::CRUD::Model we could make CX::CRUD::Object
>  superfluous. (I suggested this in an earlier email.)
>
>  So we'd have:
>
>   sub thing : Local {
>      my ($self, $c, $id) = @_;
>      my $thing = $c->model('Foo')->fetch( id => $id );

my $thing = $self->model_adaptor->fetch( id => $id );

The model adaptor should know the model it is using (and in the case
of DBIC also the table )

>      $c->stash->{object} = $thing;  # NOT a CX::CRUD::Object
>   }
>
>  and if wanted to update $thing:
>
>      $c->model('Foo')->update( $thing );

$self->model_adaptor->update( $thing );

>
>  I could live with that. Does it meet your needs? Does it make it easier to implement a
>  DBIC model and FormFu controller?
>

Yes.  In general - my point is that let's do the wrapping only for the
CRUD methods that need them.  Let's not force the user to use the CRUD
wrappers as their models.

>  --
>
> Peter Karman  .  peter at peknet.com  .  http://peknet.com/
>
>
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>
>
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>



-- 
Zbigniew Lukasiak
http://brudnopis.blogspot.com/