=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, and several changes have
+been made which could cause incompatibilities. If your application or plugin
+is using deprecated code, or relying on side-effects, then you could have
+issues upgrading to this release.
+
+Most issues found with pre-existing components have been easy to solve, and a
+complete description of behaviour changes which may cause compatibility issues,
+or warnings which are now 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 Issues with Class::C3
+
+Catalyst 5.80 uses L<Algorithm::C3> method dispatch order. This is built into
+perl 5.10, and comes via L<Class::C3> for perl 5.8. This replaces L<NEXT>
+with L<Class::C3::Adopt::NEXT>, forcing all components to resolve methods using
+C3, rather than the unpredictable dispatch order of L<NEXT>.
+
+To be able to do this, however, entails that the graph of superclasses for each
+class must be linearizable using the C3 algorithm. Unfortunately, when
+superclasses are being used as mixins, it is easy to get this wrong.
+
+Most common is the case of:
+
+ package Component1; # Note, this is the common case
+ use base qw/Class::Accessor::Fast Class::Data::Inheritable/;
-You need at least version FIXME of Catalyst::Plugin::Authentication.
+ package Component2; # Accidentally saying it this way round causes fail.
+ use base qw/Class::Data::Inheritable Class::Accessor::Fast/;
-=head2 Moose applications
+ package GoesBang;
+ use base qw/Component1 Component2/;
-Moose components for Catalyst 5.70 needed to do
+And the Catalyst plugin most often causing this, is
+L<Catalyst::Plugin::Sesssion::Store::FastMMap> - if you are using this plugin
+and see issues, then please upgrade!
+This can, however, be found in your own application - the only solution is to
+go through each base class of the class the error was reported against, until
+you identify the ones in conflict, and resolve them.
+
+=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 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 > declaration needs to occur in a begin block for
+L<attributes> to operate correctly.
+
+You also don't get the L<Moose::Object> constructor, and therefore attribute
+initialization will not work as normally expected. If you want to use Moose
+attributes, then they need to be made lazy to correctly initialize.
+
+Note that this only applies if your component needs to maintain component
+backwards compatibility for Catalyst versions before 5.71001 - in 5.71001
+attributes work as expected, and the BUILD method is called normally
+(although BUILDARGS is not).
+
+If you depend on Catalyst 5.8, then B<all> Moose features work as expected.
+
+=head3 use Moose in MyApp
+
+Similar to the above, this will also fail:
+
+ package MyApp;
+ use Moose;
+ use Catalyst qw/
+ ConfigLoader
+ /;
+ __PACKAGE__->setup;
+
+If you need to use Moose in your application class (e.g. for method modifiers
+etc) then the correct technique is:
+
+ package MyApp;
+ use Moose;
+ extends 'Catalyst';
+ __PACKAGE__->setup(qw/
+ ConfigLoader
+ /);
=head2 Anonymous closures installed directly into the symbol table
into the symbol table, you may encounter breakages. The simplest solution is
to use L<Sub::Name> to name the subroutine. Example:
- #Originalcode, likely to break:
- my $full_method_name = join('::',$package_name, $method_name);
+ # Original code, likely to break:
+ my $full_method_name = join('::', $package_name, $method_name);
*$full_method_name = sub { ... };
- #Fixed Code
+ # Fixed Code
use Sub::Name 'subname';
my $full_method_name = join('::',$package_name, $method_name);
*$full_method_name = subname $full_method_name, sub { ... };
-Additionally, you can take advantage of Catalyst's use of L<Class::MOP> and
+Additionally, you can take advantage of Catalysts use of L<Class::MOP> and
install the closure using the appropriate metaclass. Example:
use Class::MOP;
my $metaclass = Moose::Meta::Class->initialize($package_name);
$metaclass->add_method($method_name => sub { ... });
-=head2 Components without new methods
+=head2 Hooking into application setup
-FIXME
+To execute code during application startup the following snippet in MyApp.pm
+used to work:
-=head2 Components without COMPONENT methods
+ sub setup {
+ my ($class, @args) = @_;
+ $class->NEXT::setup(@args);
+ ... # things to do after the actual setup
+ }
-FIXME
+With Catalyst 5.80 this won't work anymore. Due to the fact that Catalyst is
+no longer using NEXT.pm for method resolution, this no longer works. The
+functionality was only ever originally operational as L<NEXT> remembers what
+methods have already been called, and will not call them again.
-=head2 __PACKAGE__->mk_accessor('meta');
+Using this now causes infinite recursion between MyApp::setup and
+Catalyst::setup, due to other backwards compatibility issues related to how
+plugin setup works. Moose method modifiers like C<< before|after|around 'setup
+=> sub { ... }; >> also will not operate correctly on the setup method.
+
+The right way to do it is this:
+
+ after setup_finalize => sub {
+ ... # things to do after the actual setup
+ };
+
+The setup_finalize hook was introduced as a way to void this issue.
+
+=head2 Components with a new method which returns false
-Won't work due to a limitation of L<MooseX::Emulate::Class::Accessor::Fast>
+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.
-FIXME
+This behaviour makes no sense, and so has been removed. Implementing your own
+C< new > method in components is B<highly> discouraged, instead, you should
+inherit the new method from Catalyst::Component, and use Mooses BUILD
+functionality and/or Moose attributes to perform any construction work
+necessary for your class.
+
+=head2 __PACKAGE__->mk_accessor('meta');
+
+Won't work due to a limitation of L<Moose>. This is currently being fixed
+inside 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 behaviour 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 test 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/;
+ }
+
+ BaseClass->foo('base class');
+ Child->foo('sub class');
+
+ use Test::More;
+ isnt(BaseClass->can('foo'), Child->can('foo'));
-Deprecated
+=head2 Extending Catalyst::Request or other classes in an ad-hoc manor using mk_accessors
-=head2 Components which inherit Catalyst::Component's COMPONENT method, who's new method does not return a true value.
+Previously, it was possible to add additional accessors to Catalyst::Request
+(or other classes) by calling the mk_accessors class method.
-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.
+This is no longer supported - users should make a sub-class of the class whose
+behaviour they would like to change, rather than globally polluting the
+Catalyst objects.
+=head2 Confused multiple inheritance with Catalyst::Component::COMPONENT
+
+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 AND makes no sense with C3 method dispatch order), and is therefore
+no longer supported.
+
+If a COMPONENT method is detected in the inheritance hierarchy to the right
+hand side of Catalyst::Component::COMPONENT, then the following warning
+message will be emitted:
+
+ There is a COMPONENT method resolving after Catalyst::Component
+ in ${next_package}.
+
+The correct fix is to re-arrange your class' inheritance hierarchy so that the
+COMPONENT method you would like to inherit is the first (left-hand most)
+COMPONENT method in your @ISA.
=head1 WARNINGS
=head2 Methods in Catalyst::Dispatcher
-The following methods in Catalyst::Dispatcher are likely to change
-significantly in the 5.8X release series, and therefore their use is highly
-deprecated.
+The following methods in Catalyst::Dispatcher are both an implementation
+detail, which may change 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
The first time one of these methods is called, a warning will be emitted:
- Class $class is calling the deprecated method Catalyst::Dispatcher::$public_method_name,\n"
- . "this will be removed in Catalyst 5.9X"
+ Class $class is calling the deprecated method Catalyst::Dispatcher::$public_method_name,
+ this will be removed in Catalyst 5.9X
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 whose plugins currently call these methods
+should change to using the public API, or, if you do not feel the public API
+adequately supports your use-case, please email the development list to
+discuss what API features you need so that you can be appropriately supported.
-=head2 Confused multiple inheritence with Catalyst::Component::COMPONENT
+=head2 Class naming to packages defined does not correspond.
-Warning message:
+In this version of Catalyst, if a component is loaded from disk, but no
+symbols are defined in that component's name space 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.
+ require $class was successful but the package is not defined.
+
+This is to protect against confusing bugs caused by mis-typing package names,
+and will become a fatal error in a future version.
+
+Please note that 'inner packages' (via L<Devel::InnerPackage>) are still fully
+supported, this warning is only issued when component file naming does not map
+to B<any> of the packages defined within that component.
-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.
+=head2 $c->plugin method
+
+Calling the plugin method is deprecated, and calling it at runtime is B<highly
+deprecated>.
-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.
+Instead you are recommended to use L< Catalyst::Model::Adaptor > or similar to
+compose the functionality you need outside of the main application name space.
+Calling the plugin method will not be supported past Catalyst 5.81.
=cut
+
projects / catagits/Catalyst-Runtime.git / blobdiff