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.
+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 behavior changes which may cause compatibility issues,
-or warnings to be emitted is included below to help if you have problems.
+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 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/;
+
+ package Component2; # Accidentally saying it this way round causes fail.
+ use base qw/Class::Data::Inheritable Class::Accessor::Fast/;
+
+ package GoesBang;
+ use base qw/Component1 Component2/;
+
+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:
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
+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>
+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
use Moose;
BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
-Note that the C< extends > decleration needs to occur in a begin block for
+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:
to use L<Sub::Name> to name the subroutine. Example:
# Original code, likely to break:
- my $full_method_name = join('::',$package_name, $method_name);
+ my $full_method_name = join('::', $package_name, $method_name);
*$full_method_name = sub { ... };
# Fixed Code
... # 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 L<Class::C3::Adopt::NEXT>, which uses plain C3 method resolution.
+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.
-As L<NEXTs|NEXT> hacks to remember what methods have already been called, this
-causes infinite recursion between MyApp::setup and Catalyst::setup.
-
-Moose method modifiers like C<< before|after|around 'setup => sub { ... }; >>
-also will not operate correctly due to backward compatibility issues with the
-way plugin setup methods.
+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:
... # 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
Previously, if you had a component which inherited from Catalyst::COMPONENT,
the COMPONENT method.
This behaviour makes no sense, and so has been removed. Implementing your own
-new method in components is B<highly> discouraged, 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.
+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');
Previously, writing to a class data accessor would copy the accessor method
down into your package.
-This behavior has been removed. Whilst the class data is still stored
+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.
Therefore anything relying on the side-effect of the accessor being copied down
will be broken.
-The following example demonstrates the problem:
+The following test demonstrates the problem:
{
package BaseClass;
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 whos
-behavior they would like to change, rather than globally polluting the
+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
-Warning message:
+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}.
-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.
+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 both an implementation detail,
-and also 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
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 currently call these methods
+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
-adaquately supports your use-case, please email the development list to
+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 require $class was successful but the package is not defined.
+=head2 Class naming to packages defined does not correspond.
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.
+symbols are defined in that component's name space after it is loaded, this
+warning will be issued:
-This is to protect against confusing bugs caused by mis-typing package names.
+ require $class was successful but the package is not defined.
-This will become a fatal error in a future version.
+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.
=head2 $c->plugin method
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.
+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