Gantry::State::Default - Default state handler for Gantry


This module implements the default handler to control the execution context within Gantry’s handler() method.


When a request comes into Gantry a pre‐determined set of steps are executed. These pre‐determined steps can be termed "states", and the process can be called a "state machine". There are many ways to implement a "state machine", so this document will not get into the semantics of the term.

What this module does, is take Gantry's default handling of a request, and places it into a loadable module. With these "states" now in a loadable module, you can change the execution order to suit your applications needs.

Why is this desirable?

Let’s say you have an application the loads some plugins, those plugins must do a relocation for proper initialization and this relocation must be done before the controllers can execute properly. Or you want "hook" processing, using per and post "hook" plugins. With the default handler, this is not possible, with a loadable "state machine" this is now quite easy to do.

This module also moves the methods relocate() and relocate_permanently() from into this module.


To load a differant state machine you need to do the following:

    use MyApp qw{ −StateMachine=Machine };



This method is where the logic goes for your handler. It will receive two paramters:

 r_or_cgi          This is passed into Gantry’s handler() method
                   and is determined by the execution environment
                   that Gantry is running within (CGI, MP13, MP20).

 plugin_callbacks  This is determined by Gantry at runtime.


     sub state_run {
         my ($self, $r_or_cgi, $plugin_callbacks) = @_;
         # your code goes here

This method returns the name of the state machine.

$name = $self−>state_engine;


This method can be called from any controller and will relocate the user to the given location.

$self−>relocate( location );


This method can be called from any controller and will relocate the user to the given location using HTTP_MOVED_PERMANENTLY 301.

$self−>relocate_permanently( location );




Kevin L. Esteb <>


Copyright (C) 2008 Kevin L. Esteb

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.6 or, at your option, any later version of Perl 5 you may have available.

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