=head1 Upgrading to Catalyst 5.80
-Work in progress
+Most applications and plugins should run unaltered on Catalyst 5.80.
+
+However as a lot of refactoring work has taken place, several changes
+have been made which could cause incompatibilities, if your application
+or plugin is using deprecated code, or relying on side-effects then
+there could be incompatibility.
+
+Most issues found with pre-existing components have been easy to solve,
+and a complete description of behavior changes which may cause compatibility
+issues, or warnings to be emitted is included below to help if you have
+problems.
+
+If you think you have found an upgrade related issue which is not covered in
+this document, then please email the Catalyst list to discuss the problem.
=head1 Known backwards compatibility breakages.
-=head2 Catalyst::Plugin::Authentication
+=head2 Components which inherit from Moose::Object before Catalyst::Component
+
+Moose components which say:
+
+ package TestApp::Controller::Example;
+ use Moose;
+ extends qw/Moose::Object Catalyst::Component/;
+
+to use the constructor provided by Moose, whilst working if you do some hacks
+with the C< BUILDARGS > method, will not work with Catalyst 5.80 as
+C<Catalyst::Component> inherits from C<Moose::Object>, and so C< @ISA > fails
+to linearise.
-You need at least version FIXME of Catalyst::Plugin::Authentication.
+The fix for this, is to not inherit directly from C<Moose::Object>
+yourself. Having components which do not inherit their constructor from
+C<Catalyst::Component> is B<unsupported>, and has never been recommended,
+therefore you're on your own if you're using this technique. You'll need
+to detect the version of Catalyst your application is running with and deal
+with it appropriately.
-=head2 Moose applications
+You will also see this issue if you do the following:
-Applications made by early adopters, which say:
+ package TestApp::Controller::Example;
+ use Moose;
+ use base 'Catalyst::Controller';
- extends qw/Moose::Object Catalyst::Component/
+as C< use base > appends to @ISA.
-need the C<Moose::Object> removing to run with Catalyst 5.80, otherwise
-your Class' @ISA will not linearise with C3.
+The correct way to use Moose in a component in a both forward and backwards
+compatible way is:
-rafl to fix this bit :)
+ package TestApp::Controller::Root;
+ use Moose;
+ BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
+
+Note that the C< extends > decleration needs to occur in a begin block for
+L<attributes> to operate correctly.
=head2 Anonymous closures installed directly into the symbol table
my $metaclass = Moose::Meta::Class->initialize($package_name);
$metaclass->add_method($method_name => sub { ... });
-=head2 Components without new methods
+=head2 Hooking into application setup
+
+To execute code during application startup the following snippet in MyApp.pm
+used to work:
+
+ sub setup {
+ my ($class, @args) = @_;
+ $class->NEXT::setup(@args);
+ ... # things to do after the actual setup
+ }
+
+With Catalyst 5.80 this won't work anymore. Because instead of using NEXT.pm it
+relies on Class::C3::Adopt::NEXT, which doesn't remember what methods it
+already called, like NEXT does and therefore goes into a deep recursion between
+MyApp::setup and Catalyst::setup.
+
+Moose method modifiers line C<< before|after|around 'setup => sub { ... }; >>
+won't work either because of backward compatibility issues related to plugin
+setup methods.
+
+The right way to do it is this:
-FIXME
+ after setup_finalize => sub {
+ ... # things to do after the actual setup
+ };
-=head2 Components without COMPONENT methods
+=head2 Components whos new method returns false
-FIXME
+Previously, if you had a component which inherited from Catalyst::COMPONENT,
+but overrode the new method, to return false, then your class' configuration
+would be blessed into a hash on your behalf, and this would be returned from
+the COMPONENT method.
+
+This behaviour makes no sense, and so has been removed.. You are recommended to
+implement your own new method in components, instead, you should inherit the
+new method from Catalyst::Component, and use Moose's BUILD functionality to
+perform any construction work necessary for your sub-class.
=head2 __PACKAGE__->mk_accessor('meta');
-Won't work due to a limitation of L<MooseX::Emulate::Class::Accessor::Fast>
+Won't work due to a limitation of L<Moose>
-FIXME
+This is currently being fixed inside core Moose.
=head2 Class::Data::Inheritable side effects
-FIXME
+Previously, writing to a class data accessor would copy the accessor method
+down into your package.
-=head2 Extending Catalyst::Request or other classes in an ad-hoc manor using mk_accessor
+This behavior has been removed. Whilst the class data is still stored
+per-class, it is stored on the metaclass of the class defining the accessor.
-FIXME
+Therefore anything relying on the side-effect of the accessor being copied down
+will be broken.
-=head2 require $class was successful but the package is not defined.
+The following example demonstrates the problem:
-FIXME Warning
+ {
+ package BaseClass;
+ use base qw/Class::Data::Inheritable/;
+ __PACKAGE__->mk_classdata('foo');
+ }
-=head2 $c->plugin method
+ {
+ package Child;
+ use base qw/BaseClass/;
+ }
-Deprecated
+ BaseClass->foo('base class');
+ Child->foo('sub class');
-=head2 Components which inherit Catalyst::Component's COMPONENT method, who's new method does not return a true value.
+ isnt(BaseClass->can('foo'), Child->can('foo'));
-Previously if your new method returned a false value, then your class' configuration would be blessed into a hash on your behalf,
-and this would be returned from the COMPONENT method. This is no longer supported. You are not recommended to implement your own new method
-in components, instead, you should inherit the new method from Catalyst::Component, and use Moose's BUILD functionality
-to perform any construction work necessary for your sub-class.
+=head2 Extending Catalyst::Request or other classes in an ad-hoc manor using mk_accessors
+Previously, it was possible to add additional accessors to Catalyst::Request
+(or other classes) by calling the mk_accessors class method.
+
+This is no longer supported - users should make a sub-class of the class who's
+behavior they would like to change, rather than globally polluting the Catalyst
+objects.
+
+=head2 Confused multiple inheritance with Catalyst::Component::COMPONENT
+
+Warning message:
+
+ There is a COMPONENT method resolving after Catalyst::Component
+ in ${next_package}.
+
+This means that one of the packages on the right hand side of
+Catalyst::Component in your Class' inheritance hierarchy defines
+a COMPONENT method.
+
+Previously, Catalyst's COMPONENT method would delegate to the
+method on the right hand side, which could then delegate back again
+with NEXT. This (as it is insane), is no longer supported, as it
+makes no sense with C3 method dispatch order.
+
+Therefore the correct fix is to re-arrange your class' inheritance
+hierarchy so that the COMPONENT method you would like to inherit is
+the first COMPONENT method in your @ISA.
=head1 WARNINGS
=head2 Methods in Catalyst::Dispatcher
-The following methods in Catalyst::Dispatcher are likely to change
+The following methods in Catalyst::Dispatcher are likely to change
significantly in the 5.8X release series, and therefore their use is highly
deprecated.
=over
-=item tree
+=item tree
-=item dispatch_types
+=item dispatch_types
-=item registered_dispatch_types
+=item registered_dispatch_types
-=item method_action_class
+=item method_action_class
-=item action_hash
+=item action_hash
=item container_hash
You should B<NEVER> be calling any of these methods from application code.
-Plugins authors and maintainers whos plugins need to call these methods
-should email the development list to discuss your use-case, and what a
-better API should look like.
+Plugins authors and maintainers whos plugins need to call these methods should
+email the development list to discuss your use-case, and what a better API
+should look like.
-=head2 Confused multiple inheritence with Catalyst::Component::COMPONENT
+=head2 require $class was successful but the package is not defined.
-Warning message:
+In this version of Catalyst, if a component is loaded from disk, but no symbols
+are defined in that component's namespace after it is loaded, this warning will
+be issued.
- There is a COMPONENT method resolving after Catalyst::Component
- in ${next_package}.
-
-This means that one of the packages on the right hand side of
-Catalyst::Component in your Class' inheritance hierarchy defines
-a COMPONENT method.
+This is to protect against confusing bugs caused by mis-typing package names.
-Previously, Catalyst's COMPONENT method would delegate to the
-method on the right hand side, which could then delegate back again
-with NEXT. This (as it is insane), is no longer supported, as it
-makes no sense with C3 method dispatch order.
+This will become a fatal error in a future version.
-Therefore the correct fix is to re-arrange your class' inheritance
-hierarchy so that the COMPONENT method you would like to inherit is
-the first COMPONENT method in your @ISA.
+=head2 $c->plugin method
+
+Calling the plugin method is deprecated, and calling it at runtime is B<highly
+deprecated>.
+Instead you are recommended to use L< Catalyst::Model::Adaptor > or similar to
+compose the functionality you need outside of the main application namespace.
=cut
projects / catagits/Catalyst-Runtime.git / blobdiff