Cookbook.pod

NAME

HTML::FormHandler::Manual::Cookbook - FormHandler use recipes

SYNOPSIS

Collection of use recipes for HTML::FormHandler

Select lists

If you want to set the initial value of a select field to 0 (or some other default):

sub init_value_license {
   my ( $self, $field, $item ) = @_;
   return 0 unless $item && $item->license_id; 
   return $item->license_id;
}

If the table defining the choices for a select list doesn't include a 'no choice' choice, in your template:

[% f = form.field('subject_class') %]
<select id="select_sc" name="[% f.name %]">
  <option value="">--- Choose Subject Class---</option>
  [% FOR option IN f.options %]
    <option value="[% option.value %]" 
       [% IF option.value == f.fif %]selected="selected"[% END %]>
       [% option.label | html %]</option>
  [% END %] 
</select>

Customize the select list in an 'options_' method:

sub options_country
{
   my $self = shift; 
   my @rows =
      $self->schema->resultset( 'Country' )->
         search( {}, { order_by => ['rank', 'country_name'] } )->all;
   return [ map { $_->digraph, $_->country_name } @rows ];
}

The database and FormHandler forms

If you have to process the input data before saving to the database, and this is something that would be useful in other places besides your form, you should do that processing in the DBIx::Class result class.

If the pre-processing is only relevant to HTML form input, you might want to do it in the form.

fields => {
   'my_complex_field' => {
       type => 'Text',
       noupdate => 1,
    }
 }

The 'noupdate' flag is only used if an accessor actually exists in the result class, because in that case FormHandler will attempt to use the accessor to do an update. With a non-updatable field, you can process the input for the field in a number of different places, depending on what is most logical. Some of the choices are:

1) cross_validate
2) validate_model
3) model_update

The field 'clear' flag will cause that column in the database to be set to null. This flag could be set in a validation routine.

When the field is flagged 'writeonly', the value from the database will not be used to fill in the form (put in the $form->fif hash, or the field $field->fif), but a value entered in the form WILL be used to update the database.

Set up form base classes or roles for your application

You can add whatever attributes you want to your form classes. Maybe you want to save a title, or a particular navigation widget. You could even save bits of text, or retrieve them from the database. Sometimes doing it this way would be the wrong way. But it's your form, your choice. In the right circumstances, it might provide a way to keep code out of your templates and simplify your controllers.

package MyApp::Form::Base;
use Moose;
extends 'HTML::FormHandler::Model::DBIC';

has 'title' => ( isa => 'Str', is => 'rw' );
has 'nav_bar' => ( isa => 'Str', is => 'rw' );

sub summary
{
   my $self = shift;
   my $schema = $self->schema;
   my $text = $schema->resultset('Summary')->find( ... )->text;
   return $text;
}
1;

Then:

package MyApp::Form::Whatsup;
use Moose;
extends 'MyApp::Form::Base';

has '+title' => ( default => 'This page is an example of what to expect...' );
has '+nav_bar' => ( default => ... );
...
1;

And in the template:

<h1>[% form.title %]</h1>
[% form.nav_bar %]
<p><b>Summary: </b>[% form.summary %]</p>

Or you can make these customizations Moose roles.

package MyApp::Form::Role::Base;
use Moose::Role;
...

package MyApp::Form::Whatsup;
use Moose;
with 'MyApp::Form::Role::Base';
...

Access a user record in the form

You might need the user_id to create specialized select lists, or do other form processing. Add a user_id attribute to your form:

has 'user_id' => ( isa => 'Int', is => 'rw' );
 

Then pass it in when you process the form:

$form->process( item => $item, params => $c->req->parameters, user_id = $c->user->user_id );

AUTHOR

Gerda Shank, gshank@cpan.org

COPYRIGHT

This library is free software, you can redistribute it and/or modify it under the same terms as Perl itself.