
Catalyst::Delta - Overview of changes between versions of Catalyst

This is an overview of the user-visible changes to Catalyst between major Catalyst releases.
The Catalyst::Engine sub-classes have all been removed and deprecated, to be replaced with Plack handlers.
Plack is an implementation of the PSGI specification, which is a standard interface between web servers and application frameworks.
This should be no different for developers, and you should not have to migrate your applications unless you are using a custom engine already.
This change benefits Catalyst significantly by reducing the amount of code inside the framework, and means that the framework gets upstream bug fixes in Plack, and automatically gains support for any web server which a PSGI compliant handler is written for.
It also allows you more flexibility with your application, and allows the use of cross web framework 'middleware'.
Developers are recommended to read Catalyst::Upgrading for notes about upgrading, especially if you are using an unusual deployment method.
Documentation for how to take advantage of PSGI can be found in Catalyst::PSGI, and information about deploying your application has been moved to Catalyst::Manual::Deployment.
A number of modules have been updated to pass their tests or not produce deprecation warnings with the latest version of Catalyst. It is recommended that you upgrade any of these that you are using after installing this version of Catalyst.
These extensions are:
This is now deprecated, see Catalyst::Upgrading.
Has been updated to not produce deprecation warnings, upgrade recommended.
Has been updated to fix failing tests (although older versions still function perfectly with this version of Catalyst).
Has been updated to fix failing tests (although older versions still function perfectly with this version of Catalyst).
Has been updated to fix failing tests (although older versions still function perfectly with this version of Catalyst).

Please see Catalyst::Upgrading for a full description of how changes in the framework may affect your application.
Below is a brief list of features which have been deprecated in this release:
The development server restarter has been improved to be compatible with immutable Moose classes, and also to optionally use B::Hooks::OP::Check::StashChange to handle more complex application layouts correctly.
Give a private path to the Catalyst action you want to create a URI for.
Log levels have been made additive.
$res->status