=head1 Upgrading to Catalyst 5.80
-Work in progress
+Most applications and plugins should run unaltered on Catalyst 5.80.
-=head1 Known backwards compatibility breakages.
+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.
-=head2 Catalyst::Plugin::Authentication
+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.
-You need at least version FIXME of Catalyst::Plugin::Authentication.
+=head1 Known backwards compatibility breakages.
-=head2 Moose applications
+=head2 Components which inherit from Moose::Object before Catalyst::Component
-Moose components for Catalyst 5.70 needed to do
+Moose components which say:
+ package TestApp::Controller::Example;
+ use Moose;
extends qw/Moose::Object Catalyst::Component/;
-to be able to use the constructor provided by Moose. In 5.80
-C<Catalyst::Component> already inherits from C<Moose::Object>. Therefor you
-shouldn't directly inherit from C<Moose::Object> yourself, otherwise your
-Class' @ISA will not linearise with C3.
+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.
+
+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.
+
+You will also see this issue if you do the following:
+
+ package TestApp::Controller::Example;
+ use Moose;
+ use base 'Catalyst::Controller';
+
+as C< use base > appends to @ISA.
+
+The correct way to use Moose in a component in a both forward and backwards
+compatible way is:
+
+ 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 your new method returned a false value,
+
+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. T
+
+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.
+=head2 Extending Catalyst::Request or other classes in an ad-hoc manor using mk_accessors
-FIXME Warning
+Previously, it was possible to add additional accessors to Catalyst::Request (or other classes)
+by calling the mk_accessors class method.
-=head2 $c->plugin 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.
-Deprecated
+=head2 Confused multiple inheritance with Catalyst::Component::COMPONENT
-=head2 Components which inherit Catalyst::Component's COMPONENT method, who's new method does not return a true value.
+Warning message:
-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.
+ 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.
+
+=head2 Assigning lists to accessors
+
+Accessors generated by Class::Accessor::Fast will, when multiple values
+are assigned to them, store a reference to a list automatically for you.
+
+This is not currently supported by MooseX::Emulate::Class::Accessor::Fast,
+and only the first value in the list will be stored.
+
+If you are relying on this behavior, and inheriting mk_accessors from a
+Catalyst component, then your code will fail.
=head1 WARNINGS
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