3 Catalyst::Upgrading - Instructions for upgrading to the latest Catalyst
5 =head1 Upgrading to Catalyst 5.90090
7 L<Catalyst::Utils> has a new method 'inject_component' which works the same as the method of
8 the same name in L<CatalystX::InjectComponent>. You should start converting any
9 use of the non core method in your code as future changes to Catalyst will be
10 sychronized to the core method first. We reserve the right to cease support
11 of the non core version should we reach a point in time where it cannot be
12 properly supported as an external module. Luckily this should be a trivial
13 search and replace. Change all occurances of:
15 CatalystX::InjectComponent->inject(...)
19 Catalyst::Utils::inject_component(...)
21 and we expect everything to work the same (we'd consider it not working the same
22 to be a bug, and please report it.)
24 We also cored features from L<CatalystX::RoleApplicator> to compose a role into the
25 request, response and stats classes. The main difference is that with L<CatalystX::RoleApplicator>
31 use CatalystX::RoleApplicator;
33 __PACKAGE__->apply_request_class_roles(
34 qw/My::Request::Role Other::Request::Role/);
36 Whereas now we have three class attributes, 'request_class_traits', 'response_class_traits'
37 and 'stats_class_traits', so you use like this (note this value is an ArrayRef)
44 __PACKAGE__->request_class_traits([qw/
46 Other::Request::Role/]);
48 (And the same for response_class_traits and stats_class_traits. We left off the
49 traits for Engine, since that class does a lot less nowadays, and dispatcher. If you
50 used those and can share a use case, we'd be likely to support them.
52 Lastly, we have some of the feature from L<CatalystX::ComponentsFromConfig> in
53 core. This should mostly work the same way in core, except for now the
54 core version does not create an automatic base wrapper class for your configured
55 components (it requires these to be catalyst components and injects them directly.
56 So if you make heavy use of custom base classes in L<CatalystX::ComponentsFromConfig>
57 you might need a bit of work to use the core version (although there is no reason
58 to stop using L<CatalystX::ComponentsFromConfig> since it should continue to work
59 fine and we'd consider issues with it to be bugs). Here's one way to map from
60 L<CatalystX::ComponentsFromConfig> to core:
62 In L<CatalystX::ComponentsFromConfig>:
74 inject_components => {
75 'Model::MyClass' => { from_component => 'My::Class' },
82 Although the cored behavior requires more code, its better separates concerns
83 as well as plays more into core Catalyst expections of how configuration shoul
86 Also we added a new develop console mode only warning when you call a component
87 with arguments that don't expect or do anything meaningful with those args. Its
88 possible if you are logging debug mode in production (please don't...) this
89 could add verbosity to those logs if you also happen to be calling for components
90 and passing pointless arguments. We added this warning to help people not make this
91 error and to better understand the component resolution flow.
93 =head1 Upgrading to Catalyst 5.90085
95 In this version of Catalyst we made a small change to Chained Dispatching so
96 that when two or more actions all have the same path specification AND they
97 all have Args(0), we break the tie by choosing the last action defined, and
98 not the first one defined. This was done to normalize Chaining to following
99 the 'longest Path wins, and when several actions match the same Path specification
100 we choose the last defined.' rule. Previously Args(0) was hard coded to be a special
101 case such that the first action defined would match (which is not the case when
104 Its possible that this could be a breaking change for you, if you had used
105 action roles (custom or otherwise) to add additional matching rules to differentiate
106 between several Args(0) actions that share the same root action chain. For
107 example if you have code now like this:
109 sub check_default :Chained(/) CaptureArgs(0) { ... }
111 sub default_get :Chained('check_default') PathPart('') Args(0) GET {
112 pop->res->body('get3');
115 sub default_post :Chained('check_default') PathPart('') Args(0) POST {
116 pop->res->body('post3');
119 sub chain_default :Chained('check_default') PathPart('') Args(0) {
120 pop->res->body('chain_default');
123 The way that chaining will work previous is that when two or more equal actions can
124 match, the 'top' one wins. So if the request is "GET .../check_default" BOTH
125 actions 'default_get' AND 'chain_default' would match. To break the tie in
126 the case when Args is 0, we'd previous take the 'top' (or first defined) action.
127 Unfortunately this treatment of Args(0) is special case. In all other cases
128 we choose the 'last defined' action to break a tie. So this version of
129 Catalyst changed the dispatcher to make Args(0) no longer a special case for
130 breaking ties. This means that the above code must now become:
132 sub check_default :Chained(/) CaptureArgs(0) { ... }
134 sub chain_default :Chained('check_default') PathPart('') Args(0) {
135 pop->res->body('chain_default');
138 sub default_get :Chained('check_default') PathPart('') Args(0) GET {
139 pop->res->body('get3');
142 sub default_post :Chained('check_default') PathPart('') Args(0) POST {
143 pop->res->body('post3');
146 If we want it to work as expected (for example we we GET to match 'default_get' and
147 POST to match 'default_post' and any other http Method to match 'chain_default').
149 In other words Arg(0) and chained actions must now follow the normal rule where
150 in a tie the last defined action wins and you should place all your less defined
151 or 'catch all' actions first.
153 If this causes you trouble and you can't fix your code to conform, you may set the
154 application configuration setting "use_chained_args_0_special_case" to true and
155 that will revert you code to the previous behavior.
157 =head2 More backwards compatibility options with UTF-8 changes
159 In order to give better backwards compatiblity with the 5.90080+ UTF-8 changes
160 we've added several configuration options around control of how we try to decode
161 your URL keywords / query parameters.
163 C<do_not_decode_query>
165 If true, then do not try to character decode any wide characters in your
166 request URL query or keywords. Most readings of the relevent specifications
167 suggest these should be UTF-* encoded, which is the default that L<Catalyst>
168 will use, hwoever if you are creating a lot of URLs manually or have external
169 evil clients, this might cause you trouble. If you find the changes introduced
170 in Catalyst version 5.90080+ break some of your query code, you may disable
171 the UTF-8 decoding globally using this configuration.
173 This setting takes precedence over C<default_query_encoding> and
174 C<decode_query_using_global_encoding>
176 C<default_query_encoding>
178 By default we decode query and keywords in your request URL using UTF-8, which
179 is our reading of the relevent specifications. This setting allows one to
180 specify a fixed value for how to decode your query. You might need this if
181 you are doing a lot of custom encoding of your URLs and not using UTF-8.
183 This setting take precedence over C<decode_query_using_global_encoding>.
185 C<decode_query_using_global_encoding>
187 Setting this to true will default your query decoding to whatever your
188 general global encoding is (the default is UTF-8).
191 =head1 Upgrading to Catalyst 5.90080
193 UTF8 encoding is now default. For temporary backwards compatibility, if this
194 change is causing you trouble, you can disable it by setting the application
195 configuration option to undef:
197 MyApp->config(encoding => undef);
199 But please consider this a temporary measure since it is the intention that
200 UTF8 is enabled going forwards and the expectation is that other ecosystem
201 projects will assume this as well. At some point you application will not
202 correctly function without this setting.
204 As of 5.90084 we've added two additional configuration flags for more selective
205 control over some encoding changes: 'skip_body_param_unicode_decoding' and
206 'skip_complex_post_part_handling'. You may use these to more selectively
207 disable new features while you are seeking a long term fix. Please review
208 CONFIGURATION in L<Catalyst>.
210 For further information, please see L<Catalyst::UTF8>
212 A number of projects in the wider ecosystem required minor updates to be able
213 to work correctly. Here's the known list:
215 L<Catalyst::View::TT>, L<Catalyst::View::Mason>, L<Catalyst::View::HTML::Mason>,
216 L<Catalyst::View::Xslate>, L<Test::WWW::Mechanize::Catalyst>
218 You will need to update to modern versions in most cases, although quite a few
219 of these only needed minor test case and documentation changes so you will need
220 to review the changelog of each one that is relevant to you to determine your
223 =head1 Upgrading to Catalyst 5.90060
225 Starting in the v5.90059_001 development release, the regexp dispatch type is
226 no longer automatically included as a dependency. If you are still using this
227 dispatch type, you need to add L<Catalyst::DispatchType::Regex> into your build
230 The standalone distribution of Regexp will be supported for the time being, but
231 should we find that supporting it prevents us from moving L<Catalyst> forward
232 in necessary ways, we reserve the right to drop that support. It is highly
233 recommended that you use this last stage of deprecation to change your code.
235 =head1 Upgrading to Catalyst 5.90040
237 =head2 Catalyst::Plugin::Unicode::Encoding is now core
239 The previously stand alone Unicode support module L<Catalyst::Plugin::Unicode::Encoding>
240 has been brought into core as a default plugin. Going forward, all you need is
241 to add a configuration setting for the encoding type. For example:
247 __PACKAGE__->config( encoding => 'UTF-8' );
249 Please note that this is different from the old stand alone plugin which applied
250 C<UTF-8> encoding by default (that is, if you did not set an explicit
251 C<encoding> configuration value, it assumed you wanted UTF-8). In order to
252 preserve backwards compatibility you will need to explicitly turn it on via the
253 configuration setting. THIS MIGHT CHANGE IN THE FUTURE, so please consider
254 starting to test your application with proper UTF-8 support and remove all those
255 crappy hacks you munged into the code because you didn't know the Plugin
258 For people that are using the Plugin, you will note a startup warning suggesting
259 that you can remove it from the plugin list. When you do so, please remember to
260 add the configuration setting, since you can no longer rely on the default being
261 UTF-8. We'll add it for you if you continue to use the stand alone plugin and
262 we detect this, but this backwards compatibility shim will likely be removed in
263 a few releases (trying to clean up the codebase after all).
265 If you have trouble with any of this, please bring it to the attention of the
266 Catalyst maintainer group.
268 =head2 basic async and event loop support
270 This version of L<Catalyst> offers some support for using L<AnyEvent> and
271 L<IO::Async> event loops in your application. These changes should work
272 fine for most applications however if you are already trying to perform
273 some streaming, minor changes in this area of the code might affect your
274 functionality. Please see L<Catalyst::Response\write_fh> for more and for a
277 We consider this feature experimental. We will try not to break it, but we
278 reserve the right to make necessary changes to fix major issues that people
279 run into when the use this functionality in the wild.
281 =head1 Upgrading to Catalyst 5.90030
283 =head2 Regex dispatch type is deprecated.
285 The Regex dispatchtype (L<Catalyst::DispatchType::Regex>) has been deprecated.
287 You are encouraged to move your application to Chained dispatch (L<Catalyst::DispatchType::Chained>).
289 If you cannot do so, please add a dependency to Catalyst::DispatchType::Regex to your application's
292 =head1 Upgrading to Catalyst 5.9
294 The major change is that L<Plack>, a toolkit for using the L<PSGI>
295 specification, now replaces most of the subclasses of L<Catalyst::Engine>. If
296 you are using one of the standard subclasses of L<Catalyst::Engine> this
297 should be a straightforward upgrade for you. It was a design goal for
298 this release to preserve as much backwards compatibility as possible.
299 However, since L<Plack> is different from L<Catalyst::Engine>, it is
300 possible that differences exist for edge cases. Therefore, we recommend
301 that care be taken with this upgrade and that testing should be greater
302 than would be the case with a minor point update. Please inform the
303 Catalyst developers of any problems so that we can fix them and
306 It is highly recommended that you become familiar with the L<Plack> ecosystem
307 and documentation. Being able to take advantage of L<Plack> development and
308 middleware is a major bonus to this upgrade. Documentation about how to
309 take advantage of L<Plack::Middleware> by writing your own C<< .psgi >> file
310 is contained in L<Catalyst::PSGI>.
312 If you have created a custom subclass of L<Catalyst:Engine>, you will
313 need to convert it to be a subclass of L<Plack::Handler>.
315 If you are using the L<Plack> engine, L<Catalyst::Engine::PSGI>, this new
316 release supersedes that code.
318 If you are using a subclass of L<Catalyst::Engine> that is aimed at
319 nonstandard or internal/testing uses, such as
320 L<Catalyst::Engine::Embeddable>, you should still be able to continue
323 Advice for specific subclasses of L<Catalyst::Engine> follows:
325 =head2 Upgrading the FastCGI Engine
327 No upgrade is needed if your myapp_fastcgi.pl script is already upgraded
328 to use L<Catalyst::Script::FastCGI>.
330 =head2 Upgrading the mod_perl / Apache Engines
332 The engines that are built upon the various iterations of mod_perl,
333 L<Catalyst::Engine::Apache::MP13> (for mod_perl 1, and Apache 1.x) and
334 L<Catalyst::Engine::Apache2::MP20> (for mod_perl 2, and Apache 2.x),
335 should be seamless upgrades and will work using L<Plack::Handler::Apache1>
336 or L<Plack::Handler::Apache2> as required.
338 L<Catalyst::Engine::Apache2::MP19>, however, is no longer supported, as
339 Plack does not support mod_perl version 1.99. This is unlikely to be a
340 problem for anyone, as 1.99 was a brief beta-test release for mod_perl
341 2, and all users of mod_perl 1.99 are encouraged to upgrade to a
342 supported release of Apache 2 and mod_perl 2.
344 =head2 Upgrading the HTTP Engine
346 The default development server that comes with the L<Catalyst> distribution
347 should continue to work as expected with no changes as long as your C<myapp_server>
348 script is upgraded to use L<Catalyst::Script::HTTP>.
350 =head2 Upgrading the CGI Engine
352 If you were using L<Catalyst::Engine::CGI> there is no upgrade needed if your
353 myapp_cgi.pl script is already upgraded to use L<Catalyst::Script::CGI>.
355 =head2 Upgrading Catalyst::Engine::HTTP::Prefork
357 If you were using L<Catalyst::Engine::HTTP::Prefork> then L<Starman>
358 is automatically loaded. You should (at least) change your C<Makefile.PL>
359 to depend on Starman.
361 You can regenerate your C<myapp_server.pl> script with C<catalyst.pl>
362 and implement a C<MyApp::Script::Server> class that looks like this:
364 package MyApp::Script::Server;
366 use namespace::autoclean;
368 extends 'CatalystX::Script::Server::Starman';
372 This takes advantage of the new script system, and will add a number of
373 options to the standard server script as extra options are added by
376 More information about these options can be seen at
377 L<CatalystX::Script::Server::Starman/SYNOPSIS>.
379 An alternate route to implement this functionality is to write a simple .psgi
380 file for your application, and then use the L<plackup> utility to start the
383 =head2 Upgrading the PSGI Engine
385 If you were using L<Catalyst::Engine::PSGI>, this new release supersedes
386 this engine in supporting L<Plack>. By default the Engine is now always
387 L<Plack>. As a result, you can remove the dependency on
388 L<Catalyst::Engine::PSGI> in your C<Makefile.PL>.
390 Applications that were using L<Catalyst::Engine::PSGI>
391 previously should entirely continue to work in this release with no changes.
393 However, if you have an C<app.psgi> script, then you no longer need to
394 specify the PSGI engine. Instead, the L<Catalyst> application class now
395 has a new method C<psgi_app> which returns a L<PSGI> compatible coderef
396 which you can wrap in the middleware of your choice.
398 Catalyst will use the .psgi for your application if it is located in the C<home>
399 directory of the application.
401 For example, if you were using L<Catalyst::Engine::PSGI> in the past, you will
402 have written (or generated) a C<script/myapp.psgi> file similar to this one:
407 MyCatalystApp->setup_engine('PSGI');
410 enable ... # enable your desired middleware
411 sub { MyCatalystApp->run(@_) };
414 Instead, you now say:
420 enable ... #enable your desired middleware
421 MyCatalystApp->psgi_app;
424 In the simplest case:
426 MyCatalystApp->setup_engine('PSGI');
427 my $app = sub { MyCatalystApp->run(@_) }
431 my $app = MyCatalystApp->psgi_app(@_);
435 my $app = sub { MyCatalystApp->psgi_app(@_) };
436 # If you make ^^ this mistake, your app won't work, and will confuse the hell out of you!
438 You can now move C<< script/myapp.psgi >> to C<< myapp.psgi >>, and the built-in
439 Catalyst scripts and your test suite will start using your .psgi file.
441 B<NOTE:> If you rename your .psgi file without these modifications, then
442 any tests run via L<Catalyst::Test> will not be compatible with the new
443 release, and will result in the development server starting, rather than
444 the expected test running.
446 B<NOTE:> If you are directly accessing C<< $c->req->env >> to get the PSGI
447 environment then this accessor is moved to C<< $c->engine->env >>,
448 you will need to update your code.
450 =head2 Engines which are known to be broken
452 The following engines B<DO NOT> work as of Catalyst version 5.9. The
453 core team will be happy to work with the developers and/or users of
454 these engines to help them port to the new Plack/Engine system, but for
455 now, applications which are currently using these engines B<WILL NOT>
456 run without modification to the engine code.
460 =item Catalyst::Engine::Wx
462 =item Catalyst::Engine::Zeus
464 =item Catalyst::Engine::JobQueue::POE
466 =item Catalyst::Engine::XMPP2
468 =item Catalyst::Engine::SCGI
472 =head2 Engines with unknown status
474 The following engines are untested or have unknown compatibility.
475 Reports are highly encouraged:
479 =item Catalyst::Engine::Mojo
481 =item Catalyst::Engine::Server (marked as Deprecated)
483 =item Catalyst::Engine::HTTP::POE (marked as Deprecated)
487 =head2 Plack functionality
489 See L<Catalyst::PSGI>.
493 Tests should generally work the same in Catalyst 5.9, but there are
496 Previously, if using L<Catalyst::Test> and doing local requests (against
497 a local server), if the application threw an exception then this
498 exception propagated into the test.
500 This behavior has been removed, and now a 500 response will be returned
501 to the test. This change standardizes behavior, so that local test
502 requests behave similarly to remote requests.
504 =head1 Upgrading to Catalyst 5.80
506 Most applications and plugins should run unaltered on Catalyst 5.80.
508 However, a lot of refactoring work has taken place, and several changes have
509 been made which could cause incompatibilities. If your application or plugin
510 is using deprecated code, or relying on side effects, then you could have
511 issues upgrading to this release.
513 Most issues found with existing components have been easy to
514 solve. This document provides a complete description of behavior changes
515 which may cause compatibility issues, and of new Catalyst warnings which
518 If you think you have found an upgrade-related issue which is not covered in
519 this document, please email the Catalyst list to discuss the problem.
521 =head1 Moose features
523 =head2 Application class roles
525 You can only apply method modifiers after the application's C<< ->setup >>
526 method has been called. This means that modifiers will not work with methods
527 run during the call to C<< ->setup >>.
529 See L<Catalyst::Manual::ExtendingCatalyst> for more information about using
530 L<Moose> in your applications.
532 =head2 Controller actions in Moose roles
534 You can use L<MooseX::MethodAttributes::Role> if you want to declare actions
537 =head2 Using Moose in Components
539 The correct way to use Moose in a component in a both forward and backwards
542 package TestApp::Controller::Root;
544 BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
546 See L<Components which inherit from Moose::Object before Catalyst::Component>.
548 =head1 Known backwards compatibility breakages
550 =head2 Applications in a single file
552 Applications must be in their own file, and loaded at compile time. This
553 issue generally only affects the tests of CPAN distributions. Your
554 application will fail if you try to define an application inline in a
555 block, and use plugins which supply a C< new > method, then use that
556 application latter in tests within the same file.
558 This is due to the fact that Catalyst is inlining a new method on your
559 application class allowing it to be compatible with Moose. The method
560 used to do this changed in 5.80004 to avoid the possibility of reporting
561 an 'Unknown Error' if your application failed to compile.
563 =head2 Issues with Class::C3
565 Catalyst 5.80 uses the L<Algorithm::C3> method dispatch order. This is
566 built into Perl 5.10, and comes via L<Class::C3> for Perl 5.8. This
567 replaces L<NEXT> with L<Class::C3::Adopt::NEXT>, forcing all components
568 to resolve methods using C3, rather than the unpredictable dispatch
571 This issue manifests itself by your application failing to start due to an
572 error message about having a non-linear @ISA.
574 The Catalyst plugin most often causing this is
575 L<Catalyst::Plugin::Session::Store::FastMmap> - if you are using this
576 plugin and see issues, then please upgrade your plugins, as it has been
577 fixed. Note that Makefile.PL in the distribution will warn about known
578 incompatible components.
580 This issue can, however, be found in your own application - the only solution is
581 to go through each base class of the class the error was reported against, until
582 you identify the ones in conflict, and resolve them.
584 To be able to generate a linear @ISA, the list of superclasses for each
585 class must be resolvable using the C3 algorithm. Unfortunately, when
586 superclasses are being used as mixins (to add functionality used in your class),
587 and with multiple inheritance, it is easy to get this wrong.
589 Most common is the case of:
591 package Component1; # Note, this is the common case
592 use base qw/Class::Accessor::Fast Class::Data::Inheritable/;
594 package Component2; # Accidentally saying it this way causes a failure
595 use base qw/Class::Data::Inheritable Class::Accessor::Fast/;
598 use base qw/Component1 Component2/;
600 Any situation like this will cause your application to fail to start.
602 For additional documentation about this issue, and how to resolve it, see
603 L<Class::C3::Adopt::NEXT>.
605 =head2 Components which inherit from Moose::Object before Catalyst::Component
607 Moose components which say:
609 package TestApp::Controller::Example;
611 extends qw/Moose::Object Catalyst::Component/;
613 to use the constructor provided by Moose, while working (if you do some hacks
614 with the C< BUILDARGS > method), will not work with Catalyst 5.80 as
615 C<Catalyst::Component> inherits from C<Moose::Object>, and so C< @ISA > fails
618 The correct way to use Moose in a component in a both forward and backwards
621 package TestApp::Controller::Root;
623 BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
625 Note that the C< extends > declaration needs to occur in a begin block for
626 L<attributes> to operate correctly.
628 This way you do not inherit directly from C<Moose::Object>
629 yourself. Having components which do not inherit their constructor from
630 C<Catalyst::Component> is B<unsupported>, and has never been recommended,
631 therefore you're on your own if you're using this technique. You'll need
632 to detect the version of Catalyst your application is running, and deal
633 with it appropriately.
635 You also don't get the L<Moose::Object> constructor, and therefore attribute
636 initialization will not work as normally expected. If you want to use Moose
637 attributes, then they need to be made lazy to correctly initialize.
639 Note that this only applies if your component needs to maintain component
640 backwards compatibility for Catalyst versions before 5.71001 - in 5.71001
641 attributes work as expected, and the BUILD method is called normally
642 (although BUILDARGS is not).
644 If you depend on Catalyst 5.8, then B<all> Moose features work as expected.
646 You will also see this issue if you do the following:
648 package TestApp::Controller::Example;
650 use base 'Catalyst::Controller';
652 as C< use base > appends to @ISA.
654 =head3 use Moose in MyApp
656 Similar to the above, this will also fail:
665 If you need to use Moose in your application class (e.g. for method modifiers
666 etc.) then the correct technique is:
674 __PACKAGE__->config( name => 'MyApp' );
675 __PACKAGE__->setup(qw/
679 =head2 Anonymous closures installed directly into the symbol table
681 If you have any code which installs anonymous subroutine references directly
682 into the symbol table, you may encounter breakages. The simplest solution is
683 to use L<Sub::Name> to name the subroutine. Example:
685 # Original code, likely to break:
686 my $full_method_name = join('::', $package_name, $method_name);
687 *$full_method_name = sub { ... };
690 use Sub::Name 'subname';
691 my $full_method_name = join('::',$package_name, $method_name);
692 *$full_method_name = subname $full_method_name, sub { ... };
694 Additionally, you can take advantage of Catalyst's use of L<Class::MOP> and
695 install the closure using the appropriate metaclass. Example:
698 my $metaclass = Moose::Meta::Class->initialize($package_name);
699 $metaclass->add_method($method_name => sub { ... });
701 =head2 Hooking into application setup
703 To execute code during application start-up, the following snippet in MyApp.pm
707 my ($class, @args) = @_;
708 $class->NEXT::setup(@args);
709 ... # things to do after the actual setup
712 With Catalyst 5.80 this won't work anymore, because Catalyst no longer
713 uses NEXT.pm for method resolution. The functionality was only ever
714 originally operational as L<NEXT> remembers what methods have already
715 been called, and will not call them again.
717 Using this now causes infinite recursion between MyApp::setup and
718 Catalyst::setup, due to other backwards compatibility issues related to how
719 plugin setup works. Moose method modifiers like C<< before|after|around setup
720 => sub { ... }; >> also will not operate correctly on the setup method.
722 The right way to do it is this:
724 after setup_finalize => sub {
725 ... # things to do after the actual setup
728 The setup_finalize hook was introduced as a way to avoid this issue.
730 =head2 Components with a new method which returns false
732 Previously, if you had a component which inherited from Catalyst::COMPONENT,
733 but overrode the new method to return false, then your class's configuration
734 would be blessed into a hash on your behalf, and this would be returned from
735 the COMPONENT method.
737 This behavior makes no sense, and so has been removed. Implementing your own
738 C< new > method in components is B<highly> discouraged. Instead, you should
739 inherit the new method from Catalyst::Component, and use Moose's BUILD
740 functionality and/or Moose attributes to perform any construction work
741 necessary for your class.
743 =head2 __PACKAGE__->mk_accessor('meta');
745 Won't work due to a limitation of L<Moose>. This is currently being fixed
748 =head2 Class::Data::Inheritable side effects
750 Previously, writing to a class data accessor would copy the accessor method
751 down into your package.
753 This behavior has been removed. While the class data is still stored
754 per-class, it is stored on the metaclass of the class defining the accessor.
756 Therefore anything relying on the side effect of the accessor being copied down
759 The following test demonstrates the problem:
763 use base qw/Class::Data::Inheritable/;
764 __PACKAGE__->mk_classdata('foo');
769 use base qw/BaseClass/;
772 BaseClass->foo('base class');
773 Child->foo('sub class');
776 isnt(BaseClass->can('foo'), Child->can('foo'));
778 =head2 Extending Catalyst::Request or other classes in an ad hoc manner using mk_accessors
780 Previously, it was possible to add additional accessors to Catalyst::Request
781 (or other classes) by calling the mk_accessors class method.
783 This is no longer supported - users should make a subclass of the class whose
784 behavior they would like to change, rather than globally polluting the
787 =head2 Confused multiple inheritance with Catalyst::Component::COMPONENT
789 Previously, Catalyst's COMPONENT method would delegate to the method on
790 the right hand side, which could then delegate back again with
791 NEXT. This is poor practice, and in addition, makes no sense with C3
792 method dispatch order, and is therefore no longer supported.
794 If a COMPONENT method is detected in the inheritance hierarchy to the right
795 hand side of Catalyst::Component::COMPONENT, then the following warning
796 message will be emitted:
798 There is a COMPONENT method resolving after Catalyst::Component
801 The correct fix is to re-arrange your class's inheritance hierarchy so that the
802 COMPONENT method you would like to inherit is the first (left-hand most)
803 COMPONENT method in your @ISA.
805 =head2 Development server relying on environment variables
807 Previously, the development server would allow propagation of system
808 environment variables into the request environment, this has changed with the
809 adoption of Plack. You can use L<Plack::Middleware::ForceEnv> to achieve the
814 =head2 Actions in your application class
816 Having actions in your application class will now emit a warning at application
817 startup as this is deprecated. It is highly recommended that these actions are moved
818 into a MyApp::Controller::Root (as demonstrated by the scaffold application
819 generated by catalyst.pl).
821 This warning, also affects tests. You should move actions in your test,
822 creating a myTest::Controller::Root, like the following example:
824 package MyTest::Controller::Root;
829 use parent 'Catalyst::Controller';
831 __PACKAGE__->config(namespace => '');
834 my ( $self, $c ) = @_;
840 =head2 ::[MVC]:: naming scheme
842 Having packages called MyApp::[MVC]::XX is deprecated and can no longer be generated
845 This is still supported, but it is recommended that you rename your application
846 components to Model/View/Controller.
848 A warning will be issued at application startup if the ::[MVC]:: naming scheme is
851 =head2 Catalyst::Base
853 Any code using L<Catalyst::Base> will now emit a warning; this
854 module will be removed in a future release.
856 =head2 Methods in Catalyst::Dispatcher
858 The following methods in Catalyst::Dispatcher are implementation
859 details, which may change in the 5.8X release series, and therefore their use
860 is highly deprecated.
868 =item registered_dispatch_types
870 =item method_action_class
878 The first time one of these methods is called, a warning will be emitted:
880 Class $class is calling the deprecated method Catalyst::Dispatcher::$public_method_name,
881 this will be removed in Catalyst 5.9
883 You should B<NEVER> be calling any of these methods from application code.
885 Plugin authors and maintainers whose plugins currently call these methods
886 should change to using the public API, or, if you do not feel the public API
887 adequately supports your use case, please email the development list to
888 discuss what API features you need so that you can be appropriately supported.
890 =head2 Class files with names that don't correspond to the packages they define
892 In this version of Catalyst, if a component is loaded from disk, but no
893 symbols are defined in that component's name space after it is loaded, this
894 warning will be issued:
896 require $class was successful but the package is not defined.
898 This is to protect against confusing bugs caused by mistyping package names,
899 and will become a fatal error in a future version.
901 Please note that 'inner packages' (via L<Devel::InnerPackage>) are still fully
902 supported; this warning is only issued when component file naming does not map
903 to B<any> of the packages defined within that component.
905 =head2 $c->plugin method
907 Calling the plugin method is deprecated, and calling it at run time is B<highly
910 Instead you are recommended to use L<Catalyst::Model::Adaptor> or similar to
911 compose the functionality you need outside of the main application name space.
913 Calling the plugin method will not be supported past Catalyst 5.81.