[html-formfu] Perl DBI with FormFu

[Carl Franks]

2009/3/17 Manu Kaul <manu.kaul at gmail.com>:
> Hi,
> I have just started getting into Catalyst for a new project where we have to
> communicate with a Model Class written in Perl DBI which is optimized and
> uses stored procedures to do most of the work for us. I was reading through
> the FormFu documentation on CPAN to understand how I could take advantage of
> FormFu's validation features etc and leverage off the existing Perl DBI
> Model class. I found no documenation on whether it was possible for FormFu
> to talk to a Perl DBI class.... Is this even possible?
> I noticed that all the communication to the backend was through Model::DBIC
> and Resultsets. If you could provide me with some examples of how I could
> use FormFu for validation purposes and then use my existing model class to
> do the rest of the work that would be extremely useful.
> Thanks in advance and look forward to a reply.

Hi Manu,

If you create custom constraints + validators, then can access your
Catalyst context, and so access your model.

If you're using Catalyst-Controller-HTML-FormFu, it'll automatically
copy the Cat context into
    $form->stash->{context};

As an example of how to use it, here's a (slightly edited) part of the
new Validator docs:

=head1 BEST PRACTICES

Try to avoid using callbacks if possible. Below is a more maintainable
and reusable approach, which also keeps the code out of the controller.

A normal application's directory would contain:

    lib/HTML/FormFu/Constraint/MyApp/
    lib/HTML/FormFu/Validator/MyApp/
    lib/HTML/FormFu/Plugin/MyApp/
    etc.

Then, the form config file would just need:

    validator: 'MyApp::SomeValidator'

And the class would be something like this:

    package HTML::FormFu::Validator::MyApp::SomeValidator;
    use strict;
    use warnings;
    use base 'HTML::FormFu::Validator';

    sub validate_value {
        my ( $self, $value, $params ) = @_;

        my $c = $self->form->stash->{context};

        # do something here with $c->model('MyModel');
        # return 1 if valid

        # fail
        return 0;
    }

    1;

Hope this helps,
Carl