HTML::FormHandler

HTML::FormHandler Bryan Beeley Reach Systems www.reachsystems.com

Quick Moose Review Overview Functional Examples Real World Examples Limitations

Quick Moose Review Object Framework Simple Attribute/Accessor Creation Method Modifiers

Object Framework package MooseOb; use Moose; ... no Moose; package DerivedOb; use Moose; extends 'MooseOb'; ... no Moose; my $ob = DerivedOb->new; Moose

Moose Simple Attribute/Accessor Creation has 'attribute' => ( # Properties is => 'rw', # Attribute is read/write isa => 'Str', # Indicate a type ); … $obj->attribute('value'); … $val = $obj->attribute();

Moose Method Modifiers package Base; use Moose; sub method { print “inside ”; } package Derived; use Moose; extends 'Base'; before 'method' => sub { print “before ”; }; around 'method' => sub { my $orig = shift; my $self = shift; print “around ”; $self->$orig(@_); # prints inside print “around ”; }; after 'method' => sub { print “after ”; };

HTML::FormHandler Overview HFH and MVC Forms Simple Example Object Creation Parameter Processing Validation Failed Validation Form Rendering Updating the Data Model Repeatable Fields

Model View Controller Form? HFH and MVC

Forms
Fields
Type
Name
Value
Initial
Input
Validated

Forms – Top level object
Fields – Objects within a form
Type – The class of the field object
Name – An attribute of the field object
Value – Attributes of the field object
Initial – Separate Attribute
Input – Separate Attribute (associted with a result object)
Validated – Separate Attribute

package Form; use HTML::FormHandler::Moose; extends 'HTML::FormHandler'; has_field 'column_name' => ( type => 'Text' ); has_field 'submit' => ( type => 'Submit' ); no HTML::FormHandler::Moose; … my $form = Form->new( item => $object ); $form->process( $params ); if ($form->validated) { # Form submitted successfully } else { $output = $form->render; }

package Form; use HTML::FormHandler::Moose; extends 'HTML::FormHandler::Model::DBIC'; use namespace::autoclean; has_field 'column_name' => ( type => 'Text' ); has_field 'submit' => ( type => 'Submit' ); __PACKAGE__->make_immutable; … my $form = Form->new( item => $dbic_row_ob ); $form->process( $c->req->parameters ); if ($form->validated) { # Redirect or something } else { my $output = $form->render; $c->stash->{template} = $output; }

Object Creation
No attributes and no model required
my $form = Form->new;
Attributes and row object
my $form = Form->new(
attr => 'val',
item => $row_ob
);
Dynamic form
my $form = HTML::FormHandler->new(
field_list => [
text => { type => 'Text' },
number => { type => 'Integer' },
],
);

$form->process; $form->process( $params ); my $success = $form->process( params => $params, arg => $arg, ); Parses form data out of parameters Saves input data in field objects Validates input data Generates error messages if appropriate Parameter Processing

Validation Default has_field 'number' => ( type => 'Integer', required => 1, ); In your form class has_field 'no_spaces' => ( type => 'Text' ); sub validate_no_spaces { my ($self, $field) = @_; $form->add_error('Must not have spaces') if $field->value =~ /s/; } In your field class sub validate { my $self = shift; ... $self->add_error('My custom message') if $error; }

Failed Validation Check the process return value my $success = $form->process; Add an error message $field->add_error('Error message'); Check a form for errors if ($form->has_errors) { … } Check a field for errors if ($field->has_errors) { … } Get form error messages my @error_messages = $form->errors;

Form Rendering Render into a scalar using HFH widgets my $output = $form->render; Render in a Template Toolkit template using HFH widgets [% form.render %] Let Template Toolkit do the work [% f = form.field('my_text_field') %] Enter some text: <input type=”text” name=”[% f.html_name %]” value=”[% f.html_filter(f.fif) %]” />

Updating the Data Model Use the HFH Model Interface in your form extends 'HTML::FormHandler::Model::DBIC'; Roll your own form update_model method sub update_model { … } Use any object that with accessors matching field names $form->process( item => $object, params => $params );

Repeatable Fields has_field 'order_id' => ( type => 'PosInteger' ); has_field 'cart_items' => ( type => 'Repeatable' ); has_field 'cart_items.cost' => ( type => 'Money' ); has_field 'cart_items.name' => ( type => 'Text' ) ; … JavaScript to dynamically add items to the cart … DBIC extension will submit rows into the related table

Functional Examples

Real World Examples

Default rendering is very primitive HFH DBIC model has problems in some cases Repeatable fields forget initial values new and process do the same thing twice Limitations

Workarounds and Solutions Override render, or create your own widgets Write your own update_model Patches are welcome Cache form objects

HTML::FormHandler

by bbeeley on Apr 28, 2010

Accessibility

Categories

Upload Details

Usage Rights

1 Embed 18

Statistics

HTML::FormHandler Presentation Transcript