[Catalyst] Forms: Chapter 1647

[Carl Franks]

On 24/05/07, Christopher H. Laco <claco at chrislaco.com> wrote:
> One of the never ending topics for Catalyst seems to be forms: how to
> build them, validate them, localize them and generally just live with
> them without hating the toolset or wanting to strangle someone.
>
> I don't have a solution for everyone, but I did create a solution for
> me. I offer it here as yet another piece of the puzzle for those in need
> of another path. Feel free to steal the code as you see fit.
>
> In general, I like FormBuilder for building forms, but I hate its
> validation. I like FormValidator::Simples ability to accept yaml profile
> configs (ProfileManager::YAML). I hate that it can't also take messages
> from yaml, or both in the same shot. And most of all, I hate having to
> have at least 3 configs: FB, Profile, Messages) and nothing localizing
> everything in the same way. This is a marriage of all three.
>
> The config file format is simple. The root data is FB options. The
> fields collection holds FB field config and constraints (FVS options)
> and messages (FVS messages)
>
> >     ---
> >     name: form_name
> >     method: POST
> >     javascript: 0
> >     stylesheet: 1
> >     sticky: 1
> >     submit: LABEL_CREATE
> >     fields:
> >       - sku:
> >           type: text
> >           size: 25
> >           maxlength: 25
> >           constraints:
> >             - NOT_BLANK
> >             - LENGTH, 1, 25
> >             - UNIQUE
> >           messages:
> >             - NOT_BLANK: "sku may not be blank"
> >       - name:
> >           type: text
> >           size: 25
> >           maxlength: 25
> >           constraints:
> >             - NOT_BLANK
> >             - LENGTH, 1, 25
>
>
> If you don't specify a message for a constraint, it defaults to
> FIELDNAME_CONSTRAINT. If you don't label a field, it defaults to
> LABEL_FIELDNAME. In my case, I use those as keys to a %Lexicon in a I18N
> module...they could just as well be real names/messages.
>
> If you won't want to use yaml, you can just pass the same data structure
> to parse/new
>
> > {
> >    name => 'form_name',
> >    method => 'POST'
> >    fields => [
> >       sku => {
> >           type => 'text',
> >           constraints => [
> >               'NOT_BLANK',
> >               'LENGTH, 1, 25'
> >           ]
> >       }
> >    ]
> > }
>
> When the form is validated/rendered, the labels and messages are all
> passed to an I18N sub you specify for localization...
>
> The api mostly mimics FB usage:
>
> > my $form = Mango::Form->new({
> >   source => 'path/to/some/config.yml',
> >   values => $object->get_columns,
> >   localizer => sub {MyI18N->localize(@_)},
> >   params => $c->request
> > });
> >
> > $form->field(name => 'someselect', options => \@options);
> >
> > $form->render;
> >
> > if ($form->submitted) {
> >   my $results = $form->validate;
> >   if (!$results->success) {
> >       print @{$results->errors};
> >   };
> > };
>
> The code isn't the greatest under the covers and does some evil , but it
> works for me and at least separated my form handling from my controllers
> with an API.
>
> You can steal the form code from here:
> http://svn.mangoframework.com/CPAN/Mango/trunk/lib/Mango/Form.pm
>
> Here's a real config:
> http://svn.mangoframework.com/CPAN/Mango/trunk/share/forms/admin/products/create.yml
>
> It'll change. It'll evolve. It works for me, for now. Have fun with it
> if you need it, or parts of it. :-)

The syntax, the usage, the I18N, it all seems strangely familiar...
http://html-formfu.googlecode.com/svn/
;)

Carl