+=head1 NAME
+
+Catalyst::Upgrading - Instructions for upgrading to the latest Catalyst
+
=head1 Upgrading to Catalyst 5.80
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 upgrding to this release.
+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,
+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
=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>.
+
+This issue is characterised by your application failing to start due to an
+error message about having a non-linear @ISA.
+
+The Catalyst plugin most often causing this, is
+L<Catalyst::Plugin::Session::Store::FastMmap> - if you are using this plugin
+and see issues, then please upgrade - and please try upgrading your plugins
+if you have this issue, as it has been fixed. Note that Makefile.PL in the
+distribution will warn about known incompatible components.
+
+This issue 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.
+
+To be able to generate a linear @ISA, the list of superclasses for each
+class must be resolvable using the C3 algorithm. Unfortunately, when
+superclasses are being used as mixins (to add functionality used in your class),
+and with multiple inheritence, 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/;
+
+Any situation like this will cause your application to fail to start.
+
+Please see additional documentation about this issue, and how to resolve it in
+L<Class::C3::Adopt::NEXT>.
+
=head2 Components which inherit from Moose::Object before Catalyst::Component
Moose components which say:
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.
+to linearize.
The fix for this is to not inherit directly from C<Moose::Object>
yourself. Having components which do not inherit their constructor from
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. 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 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
*$full_method_name = subname $full_method_name, sub { ... };
Additionally, you can take advantage of Catalysts use of L<Class::MOP> and
-install the closure using the appropriate metaclass. Example:
+install the closure using the appropriate meta class. Example:
use Class::MOP;
my $metaclass = Moose::Meta::Class->initialize($package_name);
=head2 Hooking into application setup
-To execute code during application startup the following snippet in MyApp.pm
+To execute code during application start-up the following snippet in MyApp.pm
used to work:
sub setup {
... # things to do after the actual setup
};
-The setup_finalize hook was introduced as a way to void this issue.
+The setup_finalize hook was introduced as a way to avoid this issue.
=head2 Components with a new method which returns false
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
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.
+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.
-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.
+=head1 WARNINGS
-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 Catalyst::Base
-=head1 WARNINGS
+Any code using L<Catalyst::Base> will now warn, and this module will be removed
+in a future release.
=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 files with names that don't correspond to the packages they define
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
-Calling the plugin method is deprecated, and calling it at runtime is B<highly
+Calling the plugin method is deprecated, and calling it at run time 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.
+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