HTML::FormHandler::Model - default model base class
This class defines the base attributes for FormHandler model classes. It is not
This is an empty base class that defines methods called by HTML::FormHandler to
support interfacing forms with a data store such as a database.
This module provides instructions on methods to override to create a
HTML::FormHandler::Model class to work with a specific object relational
mapping (ORM) tool.
The "item" is initialized with "build_item" the first time
$form->item is called. "item" must be defined in the model class
to fetch the object based on the item id. It should return the item's object.
Column values are fetched and updated by calling methods on the returned
For example, with Class::DBI you might return:
return $self->item_class->retrieve( $self->item_id );
The id (primary key) of the item (object) that the form is updating or has just
created. The model class should have a build_item method that can fetch the
object from the item_class for this id.
"item_class" sets and returns a value used by the model class to
access the ORM class related to a form.
has '+item_class' => ( default => 'User' );
This gives the model class a way to access the data store. If this is not a
fixed value (as above) then do not define the method in your subclass and
instead set the value when the form is created:
my $form = MyApp::Form::Users->new( item_class => $class );
The value can be any scalar (or object) needed by the specific ORM to access the
data related to the form.
A builder for 'item_class' might be to return the class of the 'item'.
Returns the guessed field type. The field name is passed as the first argument.
This is only required if using "Auto" type of fields in your form
classes. You could override this in your form class, for example, if you use a
field naming convention that indicates the field type.
The metadata info about the columns can be used to assign types.
Retrieve possible options for a given select field from the database. The
default method returns undef.
Returns an array reference of key/value pairs for the column passed in. These
values are used for the values and labels for field types that provide a list
of options to select from (e.g. Select, Multiple).
A 'Select' type field (or a field that inherits from
HTML::FormHandler::Field::Select) can set a number of scalars that control how
options are looked up:
label_column() - column that holds the label
active_column() - column that indicates if a row is acitve
sort_column() - column used for sorting the options
The default for label_column is "name".
Validates fields that are dependent on the model. This is called via the
validation process and the model class must at least validate
"unique" constraints defined in the form class.
Any errors on a field found should be set by calling the field's add_error
$field->add_error('Value must be unique in the database');
The default method does nothing.
Clear out any dynamic data for persistent object
Update the model with validated fields
FormHandler Contributors - see HTML::FormHandler
This software is copyright (c) 2017 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.