NAME

Data::MuForm::Manual::Cookbook - Cookbook recipes for using MuForm

VERSION

version 0.05

NAME

Data::MuForm::Manual::Cookbook

RECIPES

Update all fields

In FormHandler you can do something like:

    sub build_update_subfields {{
        by_flag => { contains => { wrapper_class => ['rep_elem'] } },
        by_type => { 'Select' => { wrapper_class => ['sel_wrapper'] },
                     'Boolean' => { element_class => ['sel_elem'] },
        },
    }}

You can achieve the equivalent in MuForm with:

    sub after_build_fields {
        my $self = shift;
        foreach my $field ( $self->all_repeatable_fields ) {
            $field->init_instance({ 'ra.wa.class' => ['rep_elem'] });
        }
        # the 'index' contains all fields, not just top level fields
        foreach my $field ( values %{$self->index} ) {
            if ( $field->type eq 'Select' ) {
                $field->render_args->{wrapper_attr}{class} = ['sel_wrapper'];
            }
            elsif ( $field->type eq 'Boolean' ) {
                $field->render_args->{element_attr}{class} = ['sel_elem'];
            }
        }
    }

apply roles to fields

A role to overide the 'id' attribute. (Note: you can do this is in a built-in way with the 'build_field_id' form method, but this serves as an example.):

    package My::DynamicFieldId;
    use Moo::Role;
    around 'id' => sub {
        my $orig = shift;
        my $self = shift;
        my $form_name = $self->form->name;
        return $form_name . "." . $self->full_name;
    };

Apply to the fields in an 'after_build_fields' sub.

    package My::CustomIdForm2;
    use Moo;
    use Data::MuForm::Meta;
    extends 'Data::MuForm';

    has '+name' => ( default => 'D123' );

    has_field 'foo';
    has_field 'bar';

    sub after_build_fields {
        my $self = shift;
        # the 'index' contains all fields, not just top level fields
        foreach my $field ( values %{$self->index} ) {
            Role::Tiny->apply_roles_to_object($field, 'My::DynamicFieldId');
        }
    }

Use an external validation method

The form package has an attribute to hold the coderef which will do the validation, which is called in a validate method.

    package SignupForm;
    use Moo;
    use Data::MuForm::Meta;
    extends 'Data::MuForm';

    has check_name_availability => ( is => 'ro', required => 1 );

    has_field 'name';
    has_field 'email';

    sub validate {
        my $self = shift;
        my $name = $self->value->{name};
        my $meth = $self->check_name_availability;
        if ( defined $name && length $name && !$meth->($name) ) {
            $self->field('name')->add_error('That name is taken already');
        }
    }
    1;

A non-form Perl application has a method to validate a field, such as checking in the database that a username is unique:

    package MyApp::Signup;
    use Moo;

    has 'form' => ( is => 'ro', builder => 'build_form' );
    sub build_form {
        my $self = shift;
        return SignupForm->new(
            {
                check_name_availability => sub {
                    my $name = shift;
                    return $self->username_available($name);
                },
            }
        );

    }
    sub username_available {
        my ( $self, $name ) = @_;
        return $name eq 'Sam' ? 1 : 0;
    }
    1;

Order fields from a role

Given a Moo::Role with fields:

    package MyApp::Form::Role::MyFields;
    use Moo::Role;
    use Data::MuForm::Meta;

    has_field 'r-one';
    has_field 'r-two';
    has_field 'r-three';

...And a Form class which includes those fields.

    package MyApp::Form::TestRole;
    use Moo;
    use Data::MuForm::Meta;
    extends 'Data::MuForm';

    with 'MyApp::Form::Role::MyFields';

    has_field 'f-one';
    has_field 'f-two';
    has_field 'f-three';
    has_field 'f-four';

...Order the fields in an 'order_fields' sub in the form.

    # put role fields between f-two and f-three
    sub order_fields {
        my $self = shift;
        my @form_order = (1, 2, 6, 7, 8);
        my @role_order = (3, 4, 5);
        foreach my $field ( $self->all_fields ) {
            my $order;
            if ( $field->source eq __PACKAGE__ ) {
                $order = shift @form_order;
            }
            else {
                $order = shift @role_order;
            }
            $field->order($order);
        }
    }

AUTHOR

Gerda Shank

COPYRIGHT AND LICENSE

This software is copyright (c) 2018 by Gerda Shank.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

cpanm Data::MuForm

perl -MCPAN -e shell
install Data::MuForm