Catalyst::Model::Adaptor - use a plain class as a Catalyst model

    Given a good old perl class like:

        package NotMyApp::SomeClass;
        use Moose; # to provide "new"
        sub method { 'yay' }

    Wrap it with a Catalyst model:

        package MyApp::Model::SomeClass;
        use base 'Catalyst::Model::Adaptor';
        __PACKAGE__->config( class => 'NotMyApp::SomeClass' );

    Then you can use "NotMyApp::SomeClass" from your Catalyst app:

        sub action :Whatever {
            my ($self, $c) = @_;
            my $someclass = $c->model('SomeClass');
            $someclass->method; # yay

    Note that "NotMyApp::SomeClass" is instantiated at application startup
    time. If you want the adapted class to be created for call to
    "$c->model", see Catalyst::Model::Factory instead. If you want the
    adapted class to be created once per request, see

    The idea is that you don't want your Catalyst model to be anything other
    than a line or two of glue. Using this module ensures that your Model
    classes are separate from your application and therefore are
    well-abstracted, reusable, and easily testable.

    Right now there are too many modules on CPAN that are Catalyst-specific.
    Most of the models would be better written as a class that handles most
    of the functionality with just a bit of glue to make it work nicely with
    Catalyst. This module aims to make integrating your class with Catalyst
    trivial, so you won't have to do any extra work to make your model

    For a good example of a Model that takes the right design approach, take
    a look at Catalyst::Model::DBIC::Schema. All it does is glues an
    existing DBIx::Class::Schema to Catalyst. It provides a bit of sugar,
    but no actual functionality. Everything important happens in the
    "DBIx::Class::Schema" object.

    The end result of that is that you can use your app's DBIC schema
    without ever thinking about Catalyst. This is a Good Thing.

    Catalyst is glue, not a way of life!

    Subclasses of this model accept the following configuration keys, which
    can be hard-coded like:

       package MyApp::Model::SomeClass;
       use base 'Catalyst::Model::Adaptor';
       __PACKAGE__->config( class => 'NotMyApp::SomeClass' );

    Or be specified as application config:

       package MyApp;
       MyApp->config->{'Model::SomeClass'} = { class => 'NotMyApp::SomeClass' };

    Or in your ConfigLoader-loaded config file:

         class: NotMyApp::SomeClass
           foo: ...
           bar: ...

    This is exactly like every other Catalyst component, so you should
    already know this.

    Anyway, here are the options:

    This is the name of the class you're adapting to Catalyst. It MUST be

    Your application will die horribly if it can't require this package.

    This is the name of the class method in "class" that will create an
    instance of the class. It defaults to "new".

    Your application will die horribly if it can't call this method.

    This is a hashref of arguments to pass to the constructor of "class". It
    is optional, of course. If you omit it, nothing is passed to the
    constructor (as opposed to "{}", an empty hashref).

    There are no methods that you call directly. When you call "$c->model"
    on a model that subclasses this, you'll get back an instance of the
    class being adapted, not this model.

    These methods are called by Catalyst:

    Setup this component.

    By default, the instance of your adapted class is instantiated like

        my $args = $self->prepare_arguments($app); # $app sometimes called $c

    Since a static hashref of arguments may not be what $class needs, you
    can override the following methods to change what $args is.

    NOTE: If you need to pass some args at instance time, you can do
    something like:

        my $model = $c->model('MyFoo', { foo => 'myfoo' });


        my $model = $c->model('MyFoo', foo => 'myfoo');

    This method is passed the entire configuration for the class and the
    Catalyst application, and returns the hashref of arguments to be passed
    to the constructor. If you need to get dynamic data out of your
    application to pass to the consturctor, do it here.

    By default, this method returns the "args" configuration key.


        sub prepare_arguments {
            my ($self, $app) = @_; # $app sometimes written as $c
            return { foobar => $app->config->{foobar}, baz => $self->{baz} };

    This method is passed the hashref from "prepare_arguments", mangles them
    into a form that your constructor will like, and returns the mangled
    form. If your constuctor wants a list instead of a hashref, this is your
    opportunity to do the conversion.


        sub mangle_arguments {
            my ($self, $args) = @_;
            return %$args; # now the args are a plain list

    If you need to do more than this, you might as well just write the whole
    class yourself. This module is designed to make the common case work
    with 1 line of code. For special needs, it's easier to just write the
    model yourself.

    If you need a new instance returned each time "$c->model" is called, use
    Catalyst::Model::Factory instead.

    If you need to have exactly one instance created per request, use
    Catalyst::Model::Factory::PerRequest instead.

    Jonathan Rockway "<>"

    Wallace Reis "<>"

    This module is Copyright (c) 2007 Jonathan Rockway. You may use, modify,
    and redistribute it under the same terms as Perl itself.