Before Mason Runs: MasonX::Interp::WithCallbacks

Another module for doing pre-processing with Mason.
This one subclasses a Mason core object.
Processing is done before your component is called.
Transparently integrates with Mason.

PerlModule   MyApp::Callbacks
PerlModule   MasonX::Interp::WithCallbacks
PerlSetVar   MasonInterpClass  MasonX::Interp::WithCallbacks

SetHandler   perl-script
PerlHandler  HTML::Mason::ApacheHandler

Callbacks are defined in modules:

package MyApp::Callbacks;

use base qw(Params::Callback);
__PACKAGE__->register_subclass( class_key => 'callbacks',
                                default_priority => 2 );

Callbacks are triggered by form fields:

<input type="submit" name="callbacks|login_cb" />

MasonX::Interp::WithCallbacks sees the class key "callbacks" and looks for a login method:

sub login : Callback
{
    my $self = shift;
    my $params = $cb->params;

    my $session = MyApp::session();

    my $user =
        Rapport::User->new
            ( email_address => $params->{email_address} );

    # Check that $user is an object,
    # and that the password is correct ...

    push @{ $session->{messages} }, 'Login successful.';

    $self->_set_user_cookie($user);

    $params->{redirect_to} ||= '/';
    $self->redirect( $params->{redirect_to} );
}