Fwd: Re: [html-formfu] DBIC-FormFu extension - Carl?

[Mario Minati]

On Wednesday 19 September 2007 12:16:01 Carl Franks wrote:
> On 19/09/2007, Mario Minati <mario.minati at googlemail.com> wrote:
> > On Wednesday 19 September 2007 11:02:47 Carl Franks wrote:
> > > On 18/09/2007, Mario Minati <mario.minati at googlemail.com> wrote:
> > > > If you have the following form fields:
> > > >     private_street
> > > >     private_city
> > > >     private_email
> > > >     office_street
> > > >     office_city
> > > >     office_email
> > > >
> > > > You most likely would like to save both datasets in same table:
> > > >     my $private = $user->new_related( 'data', { type => 'private' }
> > > > ); $private->populate_from_formfu( $form, { prefix_col => 'private_'
> > > > } ); my $office = $user->new_related( 'data', { type => 'office' } );
> > > > $office->populate_from_formfu( $form, { prefix_col => 'office_' } );
> > >
> > > I think a more elegant solution would be by adding support for
> > > 'nested' params, e.g.
> > >
> > > with the following input:
> > >     "private.street" => x
> > >     "private.city" => y
> > >     "private.email" => z
> > >
> > > $form->param('private') would return a hashref:
> > > {
> > >     street => x,
> > >     city => y,
> > >     email => z,
> > > }
> >
> > This idea is more general and useful.
> >
> > > (or use the alternative syntax, "private[street]", "private[city]",
> > > etc.)
> >
> > Can we get HTML problems with parameter names including '.' or '[]' (I
> > favour '.' as it would allow chaining.)
>
> There shouldn't be any problems, this approach is already used by
> CGI::Expand and Catalyst::Plugin::Params::Nested.
>
> (The idea was pinched from RoR, which uses it extensively)
>
> > > Then do something like:
> > >
> > >     $relationship->populate_from_formfu(
> > >         $form,
> > >         { param => 'private' } );
> > >
> > > Also, it's maybe not immediately helpful in this example, but I'd like
> > > to break out the logic from Element/Dojo/Repeatable.pm into a core
> > > Element/Repeatable.pm element.
> > > This could help with some relationships, as it would provide automatic
> > > handling of multiple fields by adding an increasing numerical suffix
> > > to the fieldname.
> >
> > Would you do a more deeply change in FormFu, like adding an additional
> > parameter to fieldset like
> > - fieldset
> >     my_parameters_belong_to: private
> >     elements:
> >       - type: Text
> >         name: just_name
> >
> > which will lead to 'private.just_name' in HTML code.
>
> Yes, this approach.
>
> Though I'd probably just name it:
>     nested: private

After playing and thinking a bit I came over the following points I would like 
to discuss:

1. 
We need an additional accessor for the nested name (e.g. processed_name) which 
is given to render and which is used in the templates.
This has to be done as functions use the name to find elements, so I can't 
just rewrite the name.

2.
This might lead into a caveat. Considering a form with to fieldsets for 
addresses names just 'street', 'city', ... and with the a nested Attribute in 
their respective fieldsets. The user cannot access these fields by get_field 
unless we provide a way to use the processed nested name to access the field.
I propose to autodiscover the way to find the fields by looking at the given 
name and use the processed nested names when there is a '.' or '[]' inside 
the given string.

3. 
At the moment I calculate the nested names in 'process' as I 
extended 'process' in Element and late all children from Element that 
redefine 'process' call it's ancestor.
Do you know of a better place to do this name preprocessing?

4.
The param processing is going to be tricky, as like in Catalyst someone might 
have already expanded our parameter names into arrays/hashes, we have to take 
care of that.
All elements and constraints need to use the processed nested name to access 
their parameter values.
The param functon needs to be changed as it currently expects a list of names 
for which to get the values, but we no might give an argument 'nested', so it 
has to change to only accept an array ref of names or one name and the ash 
ref with the nested name to prepend.

That's for now.

BTW:
I'm thinking of a Wizard element, that only shows a part of the 
complete form data and takes care of next and back functionallity. What do 
you think?


BTW2:
I would like to introduce a parameter in the form stash (or in form) for 
catalyst to prevent the automatic call to 'process', so that I still can add 
a callback to an element.
Is there yet a way to populate the stash from yml?

Greets,
Mario

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