+=head1 NAME
+
+Catalyst::Upgrading - Instructions for upgrading to the latest Catalyst
+
+=head1 Upgrading to Catalyst 5.90100
+
+We changed the way the middleware stash works so that it no longer localizes
+the PSGI env hashref. This was done to fix bugs where people set PSGI ENV hash
+keys and found them to disappear in certain cases. It also means that now if
+a sub applications sets stash variables, that stash will now bubble up to the
+parent application. This may be a breaking change for you since previous
+versions of this code did not allow that. A workaround is to explicitly delete
+stash keys in your sub application before returning control to the parent
+application.
+
+=head1 Upgrading to Catalyst 5.90097
+
+In older versions of Catalyst one could construct a L<URI> with a fragment (such as
+https://localhost/foo/bar#fragment) by using a '#' in the path or final argument, for
+example:
+
+ $c->uri_for($action, 'foo#fragment');
+
+This behavior was never documented and would break if using the Unicode plugin, or when
+adding a query to the arguments:
+
+ $c->uri_for($action, 'foo#fragment', +{ a=>1, b=>2});
+
+would define a fragment like "#fragment?a=1&b=2".
+
+When we introduced UTF-8 encoding by default in Catalyst 5.9008x this side effect behavior
+was broken since we started encoding the '#' when it was part of the URI path.
+
+In version 5.90095 and 5.90096 we attempted to fix this, but all we managed to do was break
+people with URIs that included '#' as part of the path data, when it was not expected to
+be a fragment delimiter.
+
+In general L<Catalyst> prefers an explicit specification rather than relying on side effects
+or domain specific mini languages. As a result we are now defining how to set a fragment
+for a URI via ->uri_for:
+
+ $c->uri_for($action_or_path, \@captures_or_args, @args, \$query, \$fragment);
+
+If you are relying on the previous side effect behavior your URLs will now encode the '#'
+delimiter, which is going to be a breaking change for you. You need to alter your code
+to match the new specification or modify uri_for for your local case. Patches to solve
+this are very welcomed, as long as they don't break existing test cases.
+
+B<NOTE> If you are using the string form of the first argument:
+
+ $c->uri_for('/foo/bar#baz')
+
+construction, we do not attempt to encode this and it will make a URL with a
+fragment of 'baz'.
+
+
+=head1 Upgrading to Catalyst 5.90095
+
+The method C<last_error> in L</Catalyst> was actually returning the first error. This has
+been fixed but there is a small chance it could be a breaking issue for you. If this gives
+you trouble changing to C<shift_errors> is the easiest workaround (although that does
+modify the error stack so if you are relying on that not being changed you should try something
+like @{$c->errors}[-1] instead. Since this method is relatively new and the cases when the
+error stack actually has more than one error in it, we feel the exposure is very low, but bug
+reports are very welcomed.
+
+=head1 Upgrading to Catalyst 5.90090
+
+L<Catalyst::Utils> has a new method 'inject_component' which works the same as the method of
+the same name in L<CatalystX::InjectComponent>. You should start converting any
+use of the non core method in your code as future changes to Catalyst will be
+synchronized to the core method first. We reserve the right to cease support
+of the non core version should we reach a point in time where it cannot be
+properly supported as an external module. Luckily this should be a trivial
+search and replace. Change all occurrences of:
+
+ CatalystX::InjectComponent->inject(...)
+
+Into
+
+ Catalyst::Utils::inject_component(...)
+
+and we expect everything to work the same (we'd consider it not working the same
+to be a bug, and please report it.)
+
+We also cored features from L<CatalystX::RoleApplicator> to compose a role into the
+request, response and stats classes. The main difference is that with L<CatalystX::RoleApplicator>
+you did:
+
+ package MyApp;
+
+ use Catalyst;
+ use CatalystX::RoleApplicator;
+
+ __PACKAGE__->apply_request_class_roles(
+ qw/My::Request::Role Other::Request::Role/);
+
+Whereas now we have three class attributes, 'request_class_traits', 'response_class_traits'
+and 'stats_class_traits', so you use like this (note this value is an ArrayRef)
+
+
+ package MyApp;
+
+ use Catalyst;
+
+ __PACKAGE__->request_class_traits([qw/
+ My::Request::Role
+ Other::Request::Role/]);
+
+(And the same for response_class_traits and stats_class_traits. We left off the
+traits for Engine, since that class does a lot less nowadays, and dispatcher. If you
+used those and can share a use case, we'd be likely to support them.
+
+Lastly, we have some of the feature from L<CatalystX::ComponentsFromConfig> in
+core. This should mostly work the same way in core, except for now the
+core version does not create an automatic base wrapper class for your configured
+components (it requires these to be catalyst components and injects them directly.
+So if you make heavy use of custom base classes in L<CatalystX::ComponentsFromConfig>
+you might need a bit of work to use the core version (although there is no reason
+to stop using L<CatalystX::ComponentsFromConfig> since it should continue to work
+fine and we'd consider issues with it to be bugs). Here's one way to map from
+L<CatalystX::ComponentsFromConfig> to core:
+
+In L<CatalystX::ComponentsFromConfig>:
+
+ MyApp->config(
+ 'Model::MyClass' => {
+ class => 'MyClass',
+ args => { %args },
+
+ });
+
+and now in core:
+
+ MyApp->config(
+ inject_components => {
+ 'Model::MyClass' => { from_component => 'My::Class' },
+ },
+ 'Model::MyClass' => {
+ %args
+ },
+ );
+
+Although the core behavior requires more code, it better separates concerns
+as well as plays more into core Catalyst expectations of how configuration should
+look.
+
+Also we added a new develop console mode only warning when you call a component
+with arguments that don't expect or do anything meaningful with those args. Its
+possible if you are logging debug mode in production (please don't...) this
+could add verbosity to those logs if you also happen to be calling for components
+and passing pointless arguments. We added this warning to help people not make this
+error and to better understand the component resolution flow.
+
+=head1 Upgrading to Catalyst 5.90085
+
+In this version of Catalyst we made a small change to Chained Dispatching so
+that when two or more actions all have the same path specification AND they
+all have Args(0), we break the tie by choosing the last action defined, and
+not the first one defined. This was done to normalize Chaining to following
+the 'longest Path wins, and when several actions match the same Path specification
+we choose the last defined.' rule. Previously Args(0) was hard coded to be a special
+case such that the first action defined would match (which is not the case when
+Args is not zero.)
+
+Its possible that this could be a breaking change for you, if you had used
+action roles (custom or otherwise) to add additional matching rules to differentiate
+between several Args(0) actions that share the same root action chain. For
+example if you have code now like this:
+
+ sub check_default :Chained(/) CaptureArgs(0) { ... }
+
+ sub default_get :Chained('check_default') PathPart('') Args(0) GET {
+ pop->res->body('get3');
+ }
+
+ sub default_post :Chained('check_default') PathPart('') Args(0) POST {
+ pop->res->body('post3');
+ }
+
+ sub chain_default :Chained('check_default') PathPart('') Args(0) {
+ pop->res->body('chain_default');
+ }
+
+The way that chaining will work previous is that when two or more equal actions can
+match, the 'top' one wins. So if the request is "GET .../check_default" BOTH
+actions 'default_get' AND 'chain_default' would match. To break the tie in
+the case when Args is 0, we'd previous take the 'top' (or first defined) action.
+Unfortunately this treatment of Args(0) is special case. In all other cases
+we choose the 'last defined' action to break a tie. So this version of
+Catalyst changed the dispatcher to make Args(0) no longer a special case for
+breaking ties. This means that the above code must now become:
+
+ sub check_default :Chained(/) CaptureArgs(0) { ... }
+
+ sub chain_default :Chained('check_default') PathPart('') Args(0) {
+ pop->res->body('chain_default');
+ }
+
+ sub default_get :Chained('check_default') PathPart('') Args(0) GET {
+ pop->res->body('get3');
+ }
+
+ sub default_post :Chained('check_default') PathPart('') Args(0) POST {
+ pop->res->body('post3');
+ }
+
+If we want it to work as expected (for example we we GET to match 'default_get' and
+POST to match 'default_post' and any other http Method to match 'chain_default').
+
+In other words Arg(0) and chained actions must now follow the normal rule where
+in a tie the last defined action wins and you should place all your less defined
+or 'catch all' actions first.
+
+If this causes you trouble and you can't fix your code to conform, you may set the
+application configuration setting "use_chained_args_0_special_case" to true and
+that will revert you code to the previous behavior.
+
+=head2 More backwards compatibility options with UTF-8 changes
+
+In order to give better backwards compatibility with the 5.90080+ UTF-8 changes
+we've added several configuration options around control of how we try to decode
+your URL keywords / query parameters.
+
+C<do_not_decode_query>
+
+If true, then do not try to character decode any wide characters in your
+request URL query or keywords. Most readings of the relevant specifications
+suggest these should be UTF-* encoded, which is the default that L<Catalyst>
+will use, however if you are creating a lot of URLs manually or have external
+evil clients, this might cause you trouble. If you find the changes introduced
+in Catalyst version 5.90080+ break some of your query code, you may disable
+the UTF-8 decoding globally using this configuration.
+
+This setting takes precedence over C<default_query_encoding> and
+C<decode_query_using_global_encoding>
+
+C<default_query_encoding>
+
+By default we decode query and keywords in your request URL using UTF-8, which
+is our reading of the relevant specifications. This setting allows one to
+specify a fixed value for how to decode your query. You might need this if
+you are doing a lot of custom encoding of your URLs and not using UTF-8.
+
+This setting take precedence over C<decode_query_using_global_encoding>.
+
+C<decode_query_using_global_encoding>
+
+Setting this to true will default your query decoding to whatever your
+general global encoding is (the default is UTF-8).
+
+
+=head1 Upgrading to Catalyst 5.90080
+
+UTF8 encoding is now default. For temporary backwards compatibility, if this
+change is causing you trouble, you can disable it by setting the application
+configuration option to undef:
+
+ MyApp->config(encoding => undef);
+
+But please consider this a temporary measure since it is the intention that
+UTF8 is enabled going forwards and the expectation is that other ecosystem
+projects will assume this as well. At some point you application will not
+correctly function without this setting.
+
+As of 5.90084 we've added two additional configuration flags for more selective
+control over some encoding changes: 'skip_body_param_unicode_decoding' and
+'skip_complex_post_part_handling'. You may use these to more selectively
+disable new features while you are seeking a long term fix. Please review
+CONFIGURATION in L<Catalyst>.
+
+For further information, please see L<Catalyst::UTF8>
+
+A number of projects in the wider ecosystem required minor updates to be able
+to work correctly. Here's the known list:
+
+L<Catalyst::View::TT>, L<Catalyst::View::Mason>, L<Catalyst::View::HTML::Mason>,
+L<Catalyst::View::Xslate>, L<Test::WWW::Mechanize::Catalyst>
+
+You will need to update to modern versions in most cases, although quite a few
+of these only needed minor test case and documentation changes so you will need
+to review the changelog of each one that is relevant to you to determine your
+true upgrade needs.
+
+=head1 Upgrading to Catalyst 5.90060
+
+Starting in the v5.90059_001 development release, the regexp dispatch type is
+no longer automatically included as a dependency. If you are still using this
+dispatch type, you need to add L<Catalyst::DispatchType::Regex> into your build
+system.
+
+The standalone distribution of Regexp will be supported for the time being, but
+should we find that supporting it prevents us from moving L<Catalyst> forward
+in necessary ways, we reserve the right to drop that support. It is highly
+recommended that you use this last stage of deprecation to change your code.
+
+=head1 Upgrading to Catalyst 5.90040
+
+=head2 Catalyst::Plugin::Unicode::Encoding is now core
+
+The previously stand alone Unicode support module L<Catalyst::Plugin::Unicode::Encoding>
+has been brought into core as a default plugin. Going forward, all you need is
+to add a configuration setting for the encoding type. For example:
+
+ package Myapp::Web;
+
+ use Catalyst;
+
+ __PACKAGE__->config( encoding => 'UTF-8' );
+
+Please note that this is different from the old stand alone plugin which applied
+C<UTF-8> encoding by default (that is, if you did not set an explicit
+C<encoding> configuration value, it assumed you wanted UTF-8). In order to
+preserve backwards compatibility you will need to explicitly turn it on via the
+configuration setting. THIS MIGHT CHANGE IN THE FUTURE, so please consider
+starting to test your application with proper UTF-8 support and remove all those
+crappy hacks you munged into the code because you didn't know the Plugin
+existed :)
+
+For people that are using the Plugin, you will note a startup warning suggesting
+that you can remove it from the plugin list. When you do so, please remember to
+add the configuration setting, since you can no longer rely on the default being
+UTF-8. We'll add it for you if you continue to use the stand alone plugin and
+we detect this, but this backwards compatibility shim will likely be removed in
+a few releases (trying to clean up the codebase after all).
+
+If you have trouble with any of this, please bring it to the attention of the
+Catalyst maintainer group.
+
+=head2 basic async and event loop support
+
+This version of L<Catalyst> offers some support for using L<AnyEvent> and
+L<IO::Async> event loops in your application. These changes should work
+fine for most applications however if you are already trying to perform
+some streaming, minor changes in this area of the code might affect your
+functionality. Please see L<Catalyst::Response\write_fh> for more and for a
+basic example.
+
+We consider this feature experimental. We will try not to break it, but we
+reserve the right to make necessary changes to fix major issues that people
+run into when the use this functionality in the wild.
+
+=head1 Upgrading to Catalyst 5.90030
+
+=head2 Regex dispatch type is deprecated.
+
+The Regex dispatchtype (L<Catalyst::DispatchType::Regex>) has been deprecated.
+
+You are encouraged to move your application to Chained dispatch (L<Catalyst::DispatchType::Chained>).
+
+If you cannot do so, please add a dependency to Catalyst::DispatchType::Regex to your application's
+Makefile.PL
+
+=head1 Upgrading to Catalyst 5.9
+
+The major change is that L<Plack>, a toolkit for using the L<PSGI>
+specification, now replaces most of the subclasses of L<Catalyst::Engine>. If
+you are using one of the standard subclasses of L<Catalyst::Engine> this
+should be a straightforward upgrade for you. It was a design goal for
+this release to preserve as much backwards compatibility as possible.
+However, since L<Plack> is different from L<Catalyst::Engine>, it is
+possible that differences exist for edge cases. Therefore, we recommend
+that care be taken with this upgrade and that testing should be greater
+than would be the case with a minor point update. Please inform the
+Catalyst developers of any problems so that we can fix them and
+incorporate tests.
+
+It is highly recommended that you become familiar with the L<Plack> ecosystem
+and documentation. Being able to take advantage of L<Plack> development and
+middleware is a major bonus to this upgrade. Documentation about how to
+take advantage of L<Plack::Middleware> by writing your own C<< .psgi >> file
+is contained in L<Catalyst::PSGI>.
+
+If you have created a custom subclass of L<Catalyst:Engine>, you will
+need to convert it to be a subclass of L<Plack::Handler>.
+
+If you are using the L<Plack> engine, L<Catalyst::Engine::PSGI>, this new
+release supersedes that code.
+
+If you are using a subclass of L<Catalyst::Engine> that is aimed at
+nonstandard or internal/testing uses, such as
+L<Catalyst::Engine::Embeddable>, you should still be able to continue
+using that engine.
+
+Advice for specific subclasses of L<Catalyst::Engine> follows:
+
+=head2 Upgrading the FastCGI Engine
+
+No upgrade is needed if your myapp_fastcgi.pl script is already upgraded
+to use L<Catalyst::Script::FastCGI>.
+
+=head2 Upgrading the mod_perl / Apache Engines
+
+The engines that are built upon the various iterations of mod_perl,
+L<Catalyst::Engine::Apache::MP13> (for mod_perl 1, and Apache 1.x) and
+L<Catalyst::Engine::Apache2::MP20> (for mod_perl 2, and Apache 2.x),
+should be seamless upgrades and will work using L<Plack::Handler::Apache1>
+or L<Plack::Handler::Apache2> as required.
+
+L<Catalyst::Engine::Apache2::MP19>, however, is no longer supported, as
+Plack does not support mod_perl version 1.99. This is unlikely to be a
+problem for anyone, as 1.99 was a brief beta-test release for mod_perl
+2, and all users of mod_perl 1.99 are encouraged to upgrade to a
+supported release of Apache 2 and mod_perl 2.
+
+=head2 Upgrading the HTTP Engine
+
+The default development server that comes with the L<Catalyst> distribution
+should continue to work as expected with no changes as long as your C<myapp_server>
+script is upgraded to use L<Catalyst::Script::HTTP>.
+
+=head2 Upgrading the CGI Engine
+
+If you were using L<Catalyst::Engine::CGI> there is no upgrade needed if your
+myapp_cgi.pl script is already upgraded to use L<Catalyst::Script::CGI>.
+
+=head2 Upgrading Catalyst::Engine::HTTP::Prefork
+
+If you were using L<Catalyst::Engine::HTTP::Prefork> then L<Starman>
+is automatically loaded. You should (at least) change your C<Makefile.PL>
+to depend on Starman.
+
+You can regenerate your C<myapp_server.pl> script with C<catalyst.pl>
+and implement a C<MyApp::Script::Server> class that looks like this:
+
+ package MyApp::Script::Server;
+ use Moose;
+ use namespace::autoclean;
+
+ extends 'CatalystX::Script::Server::Starman';
+
+ 1;
+
+This takes advantage of the new script system, and will add a number of
+options to the standard server script as extra options are added by
+Starman.
+
+More information about these options can be seen at
+L<CatalystX::Script::Server::Starman/SYNOPSIS>.
+
+An alternate route to implement this functionality is to write a simple .psgi
+file for your application, and then use the L<plackup> utility to start the
+server.
+
+=head2 Upgrading the PSGI Engine
+
+If you were using L<Catalyst::Engine::PSGI>, this new release supersedes
+this engine in supporting L<Plack>. By default the Engine is now always
+L<Plack>. As a result, you can remove the dependency on
+L<Catalyst::Engine::PSGI> in your C<Makefile.PL>.
+
+Applications that were using L<Catalyst::Engine::PSGI>
+previously should entirely continue to work in this release with no changes.
+
+However, if you have an C<app.psgi> script, then you no longer need to
+specify the PSGI engine. Instead, the L<Catalyst> application class now
+has a new method C<psgi_app> which returns a L<PSGI> compatible coderef
+which you can wrap in the middleware of your choice.
+
+Catalyst will use the .psgi for your application if it is located in the C<home>
+directory of the application.
+
+For example, if you were using L<Catalyst::Engine::PSGI> in the past, you will
+have written (or generated) a C<script/myapp.psgi> 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 say:
+
+ use Plack::Builder;
+ use MyCatalystApp;
+
+ builder {
+ enable ... #enable your desired middleware
+ MyCatalystApp->psgi_app;
+ };
+
+In the simplest case:
+
+ MyCatalystApp->setup_engine('PSGI');
+ my $app = sub { MyCatalystApp->run(@_) }
+
+becomes
+
+ my $app = MyCatalystApp->psgi_app(@_);
+
+B<NOT>:
+
+ my $app = sub { MyCatalystApp->psgi_app(@_) };
+ # If you make ^^ this mistake, your app won't work, and will confuse the hell out of you!
+
+You can now move C<< script/myapp.psgi >> to C<< myapp.psgi >>, and the built-in
+Catalyst scripts and your test suite will start using your .psgi file.
+
+B<NOTE:> If you rename your .psgi file without these modifications, then
+any tests run via L<Catalyst::Test> will not be compatible with the new
+release, and will result in the development server starting, rather than
+the expected test running.
+
+B<NOTE:> If you are directly accessing C<< $c->req->env >> to get the PSGI
+environment then this accessor is moved to C<< $c->engine->env >>,
+you will need to update your code.
+
+=head2 Engines which are known to be broken
+
+The following engines B<DO NOT> work as of Catalyst version 5.9. The
+core team will be happy to work with the developers and/or users of
+these engines to help them port to the new Plack/Engine system, but for
+now, applications which are currently using these engines B<WILL NOT>
+run without modification to the engine code.
+
+=over
+
+=item Catalyst::Engine::Wx
+
+=item Catalyst::Engine::Zeus
+
+=item Catalyst::Engine::JobQueue::POE
+
+=item Catalyst::Engine::XMPP2
+
+=item Catalyst::Engine::SCGI
+
+=back
+
+=head2 Engines with unknown status
+
+The following engines are untested or have unknown compatibility.
+Reports are highly encouraged:
+
+=over
+
+=item Catalyst::Engine::Mojo
+
+=item Catalyst::Engine::Server (marked as Deprecated)
+
+=item Catalyst::Engine::HTTP::POE (marked as Deprecated)
+
+=back
+
+=head2 Plack functionality
+
+See L<Catalyst::PSGI>.
+
+=head2 Tests in 5.9
+
+Tests should generally work the same in Catalyst 5.9, but there are
+some differences.
+
+Previously, if using L<Catalyst::Test> and doing local requests (against
+a local server), if the application threw an exception then this
+exception propagated into the test.
+
+This behavior has been removed, and now a 500 response will be returned
+to the test. This change standardizes behavior, so that local test
+requests behave similarly to remote requests.
+
=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 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
+might 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
+run during the call to C<< ->setup >>.
+
+See L<Catalyst::Manual::ExtendingCatalyst> for more information about using
+L<Moose> in your applications.
+
+=head2 Controller actions in Moose roles
+
+You can use L<MooseX::MethodAttributes::Role> 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<Components which inherit from Moose::Object before Catalyst::Component>.
+
+=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.
+
+=head2 Issues with Class::C3
+
+Catalyst 5.80 uses the 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 manifests itself by your application failing to start due to an
+error message about having a non-linear @ISA.
-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.
+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 your plugins, as it has been
+fixed. Note that Makefile.PL in the distribution will warn about known
+incompatible components.
-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.
+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.
-=head1 Known backwards compatibility breakages.
+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 inheritance, 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<Class::C3::Adopt::NEXT>.
=head2 Components which inherit from Moose::Object before Catalyst::Component
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, while 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>
+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.
+
+This way you do 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
+to detect the version of Catalyst your application is running, and deal
with it appropriately.
+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.
+
You will also see this issue if you do the following:
package TestApp::Controller::Example;
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 > decleration needs to occur in a begin block for
-L<attributes> to operate correctly.
-
=head3 use Moose in MyApp
Similar to the above, this will also fail:
__PACKAGE__->setup;
If you need to use Moose in your application class (e.g. for method modifiers
-etc) then the correct technique is:
+etc.) then the correct technique is:
package MyApp;
use Moose;
+ use Catalyst;
+
extends 'Catalyst';
+
+ __PACKAGE__->config( name => 'MyApp' );
__PACKAGE__->setup(qw/
ConfigLoader
/);
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
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<Class::MOP> and
+Additionally, you can take advantage of Catalyst's use of L<Class::MOP> and
install the closure using the appropriate metaclass. Example:
use Class::MOP;
=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
}
-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.
-
-As L<NEXTs|NEXT> hacks to remember what methods have already been called, this
-causes infinite recursion between MyApp::setup and Catalyst::setup.
+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<NEXT> remembers what methods have already
+been called, and will not call them again.
-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 avoid this issue.
+
=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
+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 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.
+This behavior 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 Moose's 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 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
+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;
BaseClass->foo('base class');
Child->foo('sub class');
-
+
use Test::More;
isnt(BaseClass->can('foo'), Child->can('foo'));
-=head2 Extending Catalyst::Request or other classes in an ad-hoc manor using mk_accessors
+=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 sub-class of the class whos
+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.
+
+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's 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.
+=head2 Development server relying on environment variables
-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.
+Previously, the development server would allow propagation of system
+environment variables into the request environment, this has changed with the
+adoption of Plack. You can use L<Plack::Middleware::ForceEnv> to achieve the
+same effect.
=head1 WARNINGS
+=head2 Actions in your application class
+
+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 warning, also affects tests. You should move actions in your test,
+creating a myTest::Controller::Root, like the following example:
+
+ package MyTest::Controller::Root;
+
+ 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<Catalyst::Base> 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 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 implementation
+details, 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 5.9
You should B<NEVER> be calling any of these methods from application code.
-Plugins authors and maintainers whos plugins currently call these methods
+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
-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 mistyping 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.
+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