X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FCatalyst%2FUpgrading.pod;h=8ce8eec4fa27761c77837896ba748068dfebcc87;hb=1e5dad0099d51c919670c0e765615937b0fd4dae;hp=78a6d6c6e5bdec8a8931cdbd63b903e1923f6684;hpb=8566c0de7c243b0ba1555e321759ca74bc1c05db;p=catagits%2FCatalyst-Runtime.git diff --git a/lib/Catalyst/Upgrading.pod b/lib/Catalyst/Upgrading.pod index 78a6d6c..8ce8eec 100644 --- a/lib/Catalyst/Upgrading.pod +++ b/lib/Catalyst/Upgrading.pod @@ -1,42 +1,296 @@ +=head1 NAME + +Catalyst::Upgrading - Instructions for upgrading to the latest Catalyst + +=head1 Upgrading to Catalyst 5.90 + +The major change is that L now replaces most of the subclasses of +L. If you are using one of the standard subclasses of +L this should be a straightforward upgrade for you. It was +a design goal for this release to be as backwardly compatible as possible. +However since L is different from L it would be +possible that edge case differences would exist. Therefore we recommend care +be taken with this upgrade and that testing should be greater than would be +the case with a minor point update. + +It is highly recommended that you become familar with the L ecosystem +and documentation. Being able to take advantage of L development and +middleware is a major bonus to this upgrade. + +If you have created a custom subclass of L you will need to +convert it to be a subclass of L. + +If you are using the L engine, L, this new +release supercedes that code. + +If you are using a subclass of L that is aimed at nonstandard +or internal / testing uses, such as L you should +still be able to continue using that engine. + +Advice for specific subclasses of L follows: + +=head2 Upgrading the FastCGI Engine + +No upgrade needed if your myapp_fastcgi.pl script is already upgraded +enough to use L. + +=head2 Upgrading the mod_perl / Apache Engines + +The engines that are build upon the various iterations of mod_perl, +L and +L should be seemless upgrades and will +work using using L or L +as required. + +L, is however no longer supported, as Plack +does not support mod_perl version 1.99??? FIXME - is this true? + +=head2 Upgrading the HTTP Engine + +The default development server that comes with the L distribution +should continue to work as expected with no changes as long as your C +script is upgraded to use L. + +=head2 Upgrading the CGI Engine + +If you were using L there is no upgrade needed if your +myapp_cgi.pl script is already upgraded enough to use L. + +=head2 Upgrading the Preforking Engine + +If you were using L then L +is automatically loaded. + +=head2 Upgrading the PSGI Engine + +If you were using L this new release supercedes this +engine in supporting L. By default the Engine is now always L. +As a result, you can stop depending on L in your +C. Additionally, if you have an C script you no longer +need to specify the PSGI engine. Instead, the L application class +now has a new method C which returns a L compatible coderef. + +For example, if you were using L in the past, you may +have written an C file similar to this one: + + use Plack::Builder; + use MyCatalytApp; + + MyCatalystApp->setup_engine('PSGI'); + + builder { + enable ... # enable your desired middleware + sub { MyCatalystApp->run(@_) }; + }; + +Instead, you now just do + + use Plack::Builder; + use MyCatalystApp; + + builder { + enable ... #enable your desired middleware + MyCatalystApp->psgi_app; + }; + +=head2 Engines with unknown status + +The following engines have untested or unknown compatibility. Reports are +highly welcomed: + + Catalyst::Engine::Embeddable + Catalyst::Engine::XMPP2 + Catalyst::Engine::SCGI + Catalyst::Engine::Mojo + Catalyst::Engine::Zeus + Catalyst::Engine::JobQueue::POE + Catalyst::Engine::Wx + Catalyst::Engine::Stomp + Catalyst::Engine::Server (Marked as Deprecated) + Catalyst::Engine::HTTP::POE (Marked as Deprecated) + +=head2 Using middleware + +XXX Should this be here or elsewhere? + +=head2 Making an app.psgi file + +=head2 Running with plackup? + =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, 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, 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. This document provides a complete description of behavior changes +which may cause compatibility issues, and of new Catalyst warnings which +be unclear. + +If you think you have found an upgrade-related issue which is not covered in +this document, please email the Catalyst list to discuss the problem. + +=head1 Moose features + +=head2 Application class roles + +You can only apply method modifiers after the application's C<< ->setup >> +method has been called. This means that modifiers will not work with methods +which run during the call to C<< ->setup >>. + +See L for more information about using +L in your applications. + +=head2 Controller actions in Moose roles + +You can use L if you want to declare actions +inside Moose roles. + +=head2 Using Moose in Components + +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 + +See L. + +=head1 Known backwards compatibility breakages + +=head2 Applications in a single file + +Applications must be in their own file, and loaded at compile time. This +issue generally only affects the tests of CPAN distributions. Your +application will fail if you try to define an application inline in a +block, and use plugins which supply a C< new > method, then use that +application latter in tests within the same file. + +This is due to the fact that Catalyst is inlining a new method on your +application class allowing it to be compatible with Moose. The method +used to do this changed in 5.80004 to avoid the possibility of reporting +an 'Unknown Error' if your application failed to compile. -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 Issues with Class::C3 -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. +Catalyst 5.80 uses the L method dispatch order. This is +built into Perl 5.10, and comes via L for Perl 5.8. This +replaces L with L, forcing all components +to resolve methods using C3, rather than the unpredictable dispatch +order of L. -=head1 Known backwards compatibility breakages. +This issue is characterised by your application failing to start due to an +error message about having a non-linear @ISA. -=head2 Moose applications +The Catalyst plugin most often causing this is +L - if you are using this +plugin and see issues, then please upgrade your plugins, as it has been +fixed. Note that Makefile.PL in the distribution will warn about known +incompatible components. -Moose components for Catalyst 5.70 needed to do +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 causes a failure + 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. + +For additional documentation about this issue, and how to resolve it, see +L. + +=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 already inherits from C. Therefore you -shouldn't directly inherit from C yourself, otherwise your -Class' @ISA will not linearize with C3. +to use the constructor provided by Moose, while 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 linearize. + +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 to operate correctly. + +This way you do 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, and deal +with it appropriately. + +You also don't get the L 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 Moose features work as expected. You will also see this issue if you do the following: - use Moose; + package TestApp::Controller::Example; + use Moose; use base 'Catalyst::Controller'; as C< use base > appends to @ISA. -FIXME - Add note about the appropriate magic to detect $Catalyst::VERSION -and work around it at compile time. +=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; + use Catalyst; + + extends 'Catalyst'; + + __PACKAGE__->config( name => 'MyApp' ); + __PACKAGE__->setup(qw/ + ConfigLoader + /); =head2 Anonymous closures installed directly into the symbol table @@ -44,11 +298,11 @@ 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: - #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 { ... }; @@ -60,91 +314,171 @@ install the closure using the appropriate metaclass. Example: my $metaclass = Moose::Meta::Class->initialize($package_name); $metaclass->add_method($method_name => sub { ... }); -=head2 Components whos new method returns false +=head2 Hooking into application setup -Previously if your new method returned a false value, +To execute code during application start-up, the following snippet in MyApp.pm +used to work: -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 + sub setup { + my ($class, @args) = @_; + $class->NEXT::setup(@args); + ... # things to do after the actual setup + } -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. +With Catalyst 5.80 this won't work anymore, because Catalyst no longer +uses NEXT.pm for method resolution. The functionality was only ever +originally operational as L 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 + }; -Won't work due to a limitation of L +The setup_finalize hook was introduced as a way to avoid this issue. -This is currently being fixed inside core Moose. +=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's configuration +would be blessed into a hash on your behalf, and this would be returned from +the COMPONENT method. + +This behavior makes no sense, and so has been removed. Implementing your own +C< new > method in components is B discouraged. Instead, you should +inherit the new method from Catalyst::Component, and use Moose's 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. This is currently being fixed +inside Moose. =head2 Class::Data::Inheritable side effects -Previously, writing to a class data accessor would copy the accessor method down into your package. +Previously, writing to a class data accessor would copy the accessor method +down into your package. + +This behavior has been removed. While 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. -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. +The following test demonstrates the problem: -Therefore anything relying on the side-effect of the accessor being copied down will be broken. + { + package BaseClass; + use base qw/Class::Data::Inheritable/; + __PACKAGE__->mk_classdata('foo'); + } -=head2 Extending Catalyst::Request or other classes in an ad-hoc manor using mk_accessors + { + package Child; + use base qw/BaseClass/; + } -Previously, it was possible to add additional accessors to Catalyst::Request (or other classes) -by calling the mk_accessors class method. + BaseClass->foo('base class'); + Child->foo('sub class'); -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. + use Test::More; + isnt(BaseClass->can('foo'), Child->can('foo')); + +=head2 Extending Catalyst::Request or other classes in an ad-hoc manner using mk_accessors + +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 subclass of the class whose +behavior 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 is poor practice, and in addition, makes no sense with C3 +method dispatch order, and is therefore no longer supported. - There is a COMPONENT method resolving after Catalyst::Component +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. +The correct fix is to re-arrange your class's inheritance hierarchy so that the +COMPONENT method you would like to inherit is the first (left-hand most) +COMPONENT method in your @ISA. -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 Assigning lists to accessors +=head2 Actions in your application class -Accessors generated by Class::Accessor::Fast will, when multiple values -are assigned to them, store a reference to a list automatically for you. +Having actions in your application class will now emit a warning at application +startup as this is deprecated. It is highly recommended that these actions are moved +into a MyApp::Controller::Root (as demonstrated by the scaffold application +generated by catalyst.pl). -This is not currently supported by MooseX::Emulate::Class::Accessor::Fast, -and only the first value in the list will be stored. +This warning, also affects tests. You should move actions in your test, +creating a myTest::Controller::Root, like the following example: -If you are relying on this behavior, and inheriting mk_accessors from a -Catalyst component, then your code will fail. + package MyTest::Controller::Root; -=head1 WARNINGS + use strict; + use warnings; + + use parent 'Catalyst::Controller'; + + __PACKAGE__->config(namespace => ''); + + sub action : Local { + my ( $self, $c ) = @_; + $c->do_something; + } + + 1; + +=head2 ::[MVC]:: naming scheme + +Having packages called MyApp::[MVC]::XX is deprecated and can no longer be generated +by catalyst.pl + +This is still supported, but it is recommended that you rename your application +components to Model/View/Controller. + +A warning will be issued at application startup if the ::[MVC]:: naming scheme is +in use. + +=head2 Catalyst::Base + +Any code using L will now emit a warning; this +module will be removed in a future release. =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 implementation +details, 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 @@ -152,29 +486,40 @@ deprecated. 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 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. +Plugin 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 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. +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: -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 mistyping package names, +and will become a fatal error in a future version. + +Please note that 'inner packages' (via L) are still fully +supported; this warning is only issued when component file naming does not map +to B of the packages defined within that component. =head2 $c->plugin method -Calling the plugin method is deprecated, and calling it at runtime is B. +Calling the plugin method is deprecated, and calling it at run time is B. + +Instead you are recommended to use L or similar to +compose the functionality you need outside of the main application name space. -Instead you are recommended to use L< Catalyst::Model::Adaptor > or similar to compose the functionality -you need outside of the main application namespace. +Calling the plugin method will not be supported past Catalyst 5.81. =cut +