X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FCatalyst%2FUpgrading.pod;h=7c454b37b517614fbfd75fb654155054d75d5cb4;hb=e11cac87d87b65a5271c2912f3fb90ec62445011;hp=8bc2209ec212a9f2910c19e0653ca843a781974d;hpb=7e2ec16eafb1be1daead8ed4b975ab42b79e31cb;p=catagits%2FCatalyst-Runtime.git diff --git a/lib/Catalyst/Upgrading.pod b/lib/Catalyst/Upgrading.pod index 8bc2209..7c454b3 100644 --- a/lib/Catalyst/Upgrading.pod +++ b/lib/Catalyst/Upgrading.pod @@ -1,84 +1,256 @@ =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 -You need at least version FIXME of Catalyst::Plugin::Authentication. +Moose components which say: -=head2 Moose applications + package TestApp::Controller::Example; + use Moose; + extends qw/Moose::Object Catalyst::Component/; -Applications made by early adopters, 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 inherits from C, and so C< @ISA > fails +to linearise. - extends qw/Moose::Object Catalyst::Component/ +The fix for this, is to not inherit directly from C +yourself. Having components which do not inherit their constructor from +C is B, 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. -need the C removing to run with Catalyst 5.80, otherwise -your Class' @ISA will not linearise with C3. +You will also see this issue if you do the following: -rafl to fix this bit :) + package TestApp::Controller::Example; + use Moose; + use base 'Catalyst::Controller'; -=head2 Components without new methods +as C< use base > appends to @ISA. -FIXME +The correct way to use Moose in a component in a both forward and backwards +compatible way is: -=head2 Components without COMPONENT methods + package TestApp::Controller::Root; + use Moose; + BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever -FIXME +Note that the C< extends > decleration needs to occur in a begin block for +L to operate correctly. -=head2 __PACKAGE__->mk_accessor('meta'); +=head3 use Moose in MyApp -Won't work due to a limitation of L +Similar to the above, this will also fail: -FIXME + package MyApp; + use Moose; + use Catalyst qw/ + ConfigLoader + /; + __PACKAGE__->setup; -=head2 Class::Data::Inheritable side effects +If you need to use Moose in your application class (e.g. for method modifiers +etc) then the correct technique is: -FIXME + package MyApp; + use Moose; + extends 'Catalyst'; + __PACKAGE__->setup(qw/ + ConfigLoader + /); -=head2 Extending Catalyst::Request or other classes in an ad-hoc manor using mk_accessor +=head2 Anonymous closures installed directly into the symbol table -FIXME +If you have any code which installs anonymous subroutine references directly +into the symbol table, you may encounter breakages. The simplest solution is +to use L to name the subroutine. Example: -=head2 require $class was successful but the package is not defined. + # Original code, likely to break: + my $full_method_name = join('::',$package_name, $method_name); + *$full_method_name = sub { ... }; + + # 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 Catalysts use of L 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 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 L, which uses plain C3 method resolution. + +As L 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. -FIXME Warning +The right way to do it is this: -=head2 Components which inherit Catalyst::Component's COMPONENT method, who's new method does not return a true value. + after setup_finalize => sub { + ... # things to do after the actual setup + }; -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 +=head2 Components with a new method which returns false + +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. Implementing your own +new method in components is B 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. +=head2 __PACKAGE__->mk_accessor('meta'); -=head Methods in Catalyst::Dispatcher +Won't work due to a limitation of L. This is currently being fixed +inside Moose. - Class $class is calling the deprecated method Catalyst::Dispatcher::$public_method_name,\n" - . "this will be removed in Catalyst 5.9X" +=head2 Class::Data::Inheritable side effects + +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 +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: + + { + package BaseClass; + use base qw/Class::Data::Inheritable/; + __PACKAGE__->mk_classdata('foo'); + } + + { + package Child; + use base qw/BaseClass/; + } + + BaseClass->foo('base class'); + Child->foo('sub class'); + + use Test::More; + isnt(BaseClass->can('foo'), Child->can('foo')); -FIXME +=head2 Extending Catalyst::Request or other classes in an ad-hoc manor using mk_accessors -=head2 Confused multiple inheritence with Catalyst::Component::COMPONENT +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 +Catalyst objects. + +=head2 Confused multiple inheritance with Catalyst::Component::COMPONENT Warning message: - There is a COMPONENT method resolving after Catalyst::Component + 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. +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 +significantly in the 5.8X release series, and therefore their use is highly +deprecated. + +=over + +=item tree + +=item dispatch_types + +=item registered_dispatch_types + +=item method_action_class + +=item action_hash + +=item container_hash + +=back + +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" + +You should B 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. + +=head2 require $class was successful but the package is not defined. + +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. + +This is to protect against confusing bugs caused by mis-typing package names. + +This will become a fatal error in a future version. + +=head2 $c->plugin method -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. +Calling the plugin method is deprecated, and calling it at runtime is B. +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