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 =head1 Upgrading to Catalyst 5.90085
26 In this version of Catalyst we made a small change to Chained Dispatching so
27 that when two or more actions all have the same path specification AND they
28 all have Args(0), we break the tie by choosing the last action defined, and
29 not the first one defined. This was done to normalize Chaining to following
30 the 'longest Path wins, and when several actions match the same Path specification
31 we choose the last defined.' rule. Previously Args(0) was hard coded to be a special
32 case such that the first action defined would match (which is not the case when
35 Its possible that this could be a breaking change for you, if you had used
36 action roles (custom or otherwise) to add additional matching rules to differentiate
37 between several Args(0) actions that share the same root action chain. For
38 example if you have code now like this:
40 sub check_default :Chained(/) CaptureArgs(0) { ... }
42 sub default_get :Chained('check_default') PathPart('') Args(0) GET {
43 pop->res->body('get3');
46 sub default_post :Chained('check_default') PathPart('') Args(0) POST {
47 pop->res->body('post3');
50 sub chain_default :Chained('check_default') PathPart('') Args(0) {
51 pop->res->body('chain_default');
54 The way that chaining will work previous is that when two or more equal actions can
55 match, the 'top' one wins. So if the request is "GET .../check_default" BOTH
56 actions 'default_get' AND 'chain_default' would match. To break the tie in
57 the case when Args is 0, we'd previous take the 'top' (or first defined) action.
58 Unfortunately this treatment of Args(0) is special case. In all other cases
59 we choose the 'last defined' action to break a tie. So this version of
60 Catalyst changed the dispatcher to make Args(0) no longer a special case for
61 breaking ties. This means that the above code must now become:
63 sub check_default :Chained(/) CaptureArgs(0) { ... }
65 sub chain_default :Chained('check_default') PathPart('') Args(0) {
66 pop->res->body('chain_default');
69 sub default_get :Chained('check_default') PathPart('') Args(0) GET {
70 pop->res->body('get3');
73 sub default_post :Chained('check_default') PathPart('') Args(0) POST {
74 pop->res->body('post3');
77 If we want it to work as expected (for example we we GET to match 'default_get' and
78 POST to match 'default_post' and any other http Method to match 'chain_default').
80 In other words Arg(0) and chained actions must now follow the normal rule where
81 in a tie the last defined action wins and you should place all your less defined
82 or 'catch all' actions first.
84 If this causes you trouble and you can't fix your code to conform, you may set the
85 application configuration setting "use_chained_args_0_special_case" to true and
86 that will revert you code to the previous behavior.
88 =head2 More backwards compatibility options with UTF-8 changes
90 In order to give better backwards compatiblity with the 5.90080+ UTF-8 changes
91 we've added several configuration options around control of how we try to decode
92 your URL keywords / query parameters.
94 C<do_not_decode_query>
96 If true, then do not try to character decode any wide characters in your
97 request URL query or keywords. Most readings of the relevent specifications
98 suggest these should be UTF-* encoded, which is the default that L<Catalyst>
99 will use, hwoever if you are creating a lot of URLs manually or have external
100 evil clients, this might cause you trouble. If you find the changes introduced
101 in Catalyst version 5.90080+ break some of your query code, you may disable
102 the UTF-8 decoding globally using this configuration.
104 This setting takes precedence over C<default_query_encoding> and
105 C<decode_query_using_global_encoding>
107 C<default_query_encoding>
109 By default we decode query and keywords in your request URL using UTF-8, which
110 is our reading of the relevent specifications. This setting allows one to
111 specify a fixed value for how to decode your query. You might need this if
112 you are doing a lot of custom encoding of your URLs and not using UTF-8.
114 This setting take precedence over C<decode_query_using_global_encoding>.
116 C<decode_query_using_global_encoding>
118 Setting this to true will default your query decoding to whatever your
119 general global encoding is (the default is UTF-8).
122 =head1 Upgrading to Catalyst 5.90080
124 UTF8 encoding is now default. For temporary backwards compatibility, if this
125 change is causing you trouble, you can disable it by setting the application
126 configuration option to undef:
128 MyApp->config(encoding => undef);
130 But please consider this a temporary measure since it is the intention that
131 UTF8 is enabled going forwards and the expectation is that other ecosystem
132 projects will assume this as well. At some point you application will not
133 correctly function without this setting.
135 As of 5.90084 we've added two additional configuration flags for more selective
136 control over some encoding changes: 'skip_body_param_unicode_decoding' and
137 'skip_complex_post_part_handling'. You may use these to more selectively
138 disable new features while you are seeking a long term fix. Please review
139 CONFIGURATION in L<Catalyst>.
141 For further information, please see L<Catalyst::UTF8>
143 A number of projects in the wider ecosystem required minor updates to be able
144 to work correctly. Here's the known list:
146 L<Catalyst::View::TT>, L<Catalyst::View::Mason>, L<Catalyst::View::HTML::Mason>,
147 L<Catalyst::View::Xslate>, L<Test::WWW::Mechanize::Catalyst>
149 You will need to update to modern versions in most cases, although quite a few
150 of these only needed minor test case and documentation changes so you will need
151 to review the changelog of each one that is relevant to you to determine your
154 =head1 Upgrading to Catalyst 5.90060
156 Starting in the v5.90059_001 development release, the regexp dispatch type is
157 no longer automatically included as a dependency. If you are still using this
158 dispatch type, you need to add L<Catalyst::DispatchType::Regex> into your build
161 The standalone distribution of Regexp will be supported for the time being, but
162 should we find that supporting it prevents us from moving L<Catalyst> forward
163 in necessary ways, we reserve the right to drop that support. It is highly
164 recommended that you use this last stage of deprecation to change your code.
166 =head1 Upgrading to Catalyst 5.90040
168 =head2 Catalyst::Plugin::Unicode::Encoding is now core
170 The previously stand alone Unicode support module L<Catalyst::Plugin::Unicode::Encoding>
171 has been brought into core as a default plugin. Going forward, all you need is
172 to add a configuration setting for the encoding type. For example:
178 __PACKAGE__->config( encoding => 'UTF-8' );
180 Please note that this is different from the old stand alone plugin which applied
181 C<UTF-8> encoding by default (that is, if you did not set an explicit
182 C<encoding> configuration value, it assumed you wanted UTF-8). In order to
183 preserve backwards compatibility you will need to explicitly turn it on via the
184 configuration setting. THIS MIGHT CHANGE IN THE FUTURE, so please consider
185 starting to test your application with proper UTF-8 support and remove all those
186 crappy hacks you munged into the code because you didn't know the Plugin
189 For people that are using the Plugin, you will note a startup warning suggesting
190 that you can remove it from the plugin list. When you do so, please remember to
191 add the configuration setting, since you can no longer rely on the default being
192 UTF-8. We'll add it for you if you continue to use the stand alone plugin and
193 we detect this, but this backwards compatibility shim will likely be removed in
194 a few releases (trying to clean up the codebase after all).
196 If you have trouble with any of this, please bring it to the attention of the
197 Catalyst maintainer group.
199 =head2 basic async and event loop support
201 This version of L<Catalyst> offers some support for using L<AnyEvent> and
202 L<IO::Async> event loops in your application. These changes should work
203 fine for most applications however if you are already trying to perform
204 some streaming, minor changes in this area of the code might affect your
205 functionality. Please see L<Catalyst::Response\write_fh> for more and for a
208 We consider this feature experimental. We will try not to break it, but we
209 reserve the right to make necessary changes to fix major issues that people
210 run into when the use this functionality in the wild.
212 =head1 Upgrading to Catalyst 5.90030
214 =head2 Regex dispatch type is deprecated.
216 The Regex dispatchtype (L<Catalyst::DispatchType::Regex>) has been deprecated.
218 You are encouraged to move your application to Chained dispatch (L<Catalyst::DispatchType::Chained>).
220 If you cannot do so, please add a dependency to Catalyst::DispatchType::Regex to your application's
223 =head1 Upgrading to Catalyst 5.9
225 The major change is that L<Plack>, a toolkit for using the L<PSGI>
226 specification, now replaces most of the subclasses of L<Catalyst::Engine>. If
227 you are using one of the standard subclasses of L<Catalyst::Engine> this
228 should be a straightforward upgrade for you. It was a design goal for
229 this release to preserve as much backwards compatibility as possible.
230 However, since L<Plack> is different from L<Catalyst::Engine>, it is
231 possible that differences exist for edge cases. Therefore, we recommend
232 that care be taken with this upgrade and that testing should be greater
233 than would be the case with a minor point update. Please inform the
234 Catalyst developers of any problems so that we can fix them and
237 It is highly recommended that you become familiar with the L<Plack> ecosystem
238 and documentation. Being able to take advantage of L<Plack> development and
239 middleware is a major bonus to this upgrade. Documentation about how to
240 take advantage of L<Plack::Middleware> by writing your own C<< .psgi >> file
241 is contained in L<Catalyst::PSGI>.
243 If you have created a custom subclass of L<Catalyst:Engine>, you will
244 need to convert it to be a subclass of L<Plack::Handler>.
246 If you are using the L<Plack> engine, L<Catalyst::Engine::PSGI>, this new
247 release supersedes that code.
249 If you are using a subclass of L<Catalyst::Engine> that is aimed at
250 nonstandard or internal/testing uses, such as
251 L<Catalyst::Engine::Embeddable>, you should still be able to continue
254 Advice for specific subclasses of L<Catalyst::Engine> follows:
256 =head2 Upgrading the FastCGI Engine
258 No upgrade is needed if your myapp_fastcgi.pl script is already upgraded
259 to use L<Catalyst::Script::FastCGI>.
261 =head2 Upgrading the mod_perl / Apache Engines
263 The engines that are built upon the various iterations of mod_perl,
264 L<Catalyst::Engine::Apache::MP13> (for mod_perl 1, and Apache 1.x) and
265 L<Catalyst::Engine::Apache2::MP20> (for mod_perl 2, and Apache 2.x),
266 should be seamless upgrades and will work using L<Plack::Handler::Apache1>
267 or L<Plack::Handler::Apache2> as required.
269 L<Catalyst::Engine::Apache2::MP19>, however, is no longer supported, as
270 Plack does not support mod_perl version 1.99. This is unlikely to be a
271 problem for anyone, as 1.99 was a brief beta-test release for mod_perl
272 2, and all users of mod_perl 1.99 are encouraged to upgrade to a
273 supported release of Apache 2 and mod_perl 2.
275 =head2 Upgrading the HTTP Engine
277 The default development server that comes with the L<Catalyst> distribution
278 should continue to work as expected with no changes as long as your C<myapp_server>
279 script is upgraded to use L<Catalyst::Script::HTTP>.
281 =head2 Upgrading the CGI Engine
283 If you were using L<Catalyst::Engine::CGI> there is no upgrade needed if your
284 myapp_cgi.pl script is already upgraded to use L<Catalyst::Script::CGI>.
286 =head2 Upgrading Catalyst::Engine::HTTP::Prefork
288 If you were using L<Catalyst::Engine::HTTP::Prefork> then L<Starman>
289 is automatically loaded. You should (at least) change your C<Makefile.PL>
290 to depend on Starman.
292 You can regenerate your C<myapp_server.pl> script with C<catalyst.pl>
293 and implement a C<MyApp::Script::Server> class that looks like this:
295 package MyApp::Script::Server;
297 use namespace::autoclean;
299 extends 'CatalystX::Script::Server::Starman';
303 This takes advantage of the new script system, and will add a number of
304 options to the standard server script as extra options are added by
307 More information about these options can be seen at
308 L<CatalystX::Script::Server::Starman/SYNOPSIS>.
310 An alternate route to implement this functionality is to write a simple .psgi
311 file for your application, and then use the L<plackup> utility to start the
314 =head2 Upgrading the PSGI Engine
316 If you were using L<Catalyst::Engine::PSGI>, this new release supersedes
317 this engine in supporting L<Plack>. By default the Engine is now always
318 L<Plack>. As a result, you can remove the dependency on
319 L<Catalyst::Engine::PSGI> in your C<Makefile.PL>.
321 Applications that were using L<Catalyst::Engine::PSGI>
322 previously should entirely continue to work in this release with no changes.
324 However, if you have an C<app.psgi> script, then you no longer need to
325 specify the PSGI engine. Instead, the L<Catalyst> application class now
326 has a new method C<psgi_app> which returns a L<PSGI> compatible coderef
327 which you can wrap in the middleware of your choice.
329 Catalyst will use the .psgi for your application if it is located in the C<home>
330 directory of the application.
332 For example, if you were using L<Catalyst::Engine::PSGI> in the past, you will
333 have written (or generated) a C<script/myapp.psgi> file similar to this one:
338 MyCatalystApp->setup_engine('PSGI');
341 enable ... # enable your desired middleware
342 sub { MyCatalystApp->run(@_) };
345 Instead, you now say:
351 enable ... #enable your desired middleware
352 MyCatalystApp->psgi_app;
355 In the simplest case:
357 MyCatalystApp->setup_engine('PSGI');
358 my $app = sub { MyCatalystApp->run(@_) }
362 my $app = MyCatalystApp->psgi_app(@_);
366 my $app = sub { MyCatalystApp->psgi_app(@_) };
367 # If you make ^^ this mistake, your app won't work, and will confuse the hell out of you!
369 You can now move C<< script/myapp.psgi >> to C<< myapp.psgi >>, and the built-in
370 Catalyst scripts and your test suite will start using your .psgi file.
372 B<NOTE:> If you rename your .psgi file without these modifications, then
373 any tests run via L<Catalyst::Test> will not be compatible with the new
374 release, and will result in the development server starting, rather than
375 the expected test running.
377 B<NOTE:> If you are directly accessing C<< $c->req->env >> to get the PSGI
378 environment then this accessor is moved to C<< $c->engine->env >>,
379 you will need to update your code.
381 =head2 Engines which are known to be broken
383 The following engines B<DO NOT> work as of Catalyst version 5.9. The
384 core team will be happy to work with the developers and/or users of
385 these engines to help them port to the new Plack/Engine system, but for
386 now, applications which are currently using these engines B<WILL NOT>
387 run without modification to the engine code.
391 =item Catalyst::Engine::Wx
393 =item Catalyst::Engine::Zeus
395 =item Catalyst::Engine::JobQueue::POE
397 =item Catalyst::Engine::XMPP2
399 =item Catalyst::Engine::SCGI
403 =head2 Engines with unknown status
405 The following engines are untested or have unknown compatibility.
406 Reports are highly encouraged:
410 =item Catalyst::Engine::Mojo
412 =item Catalyst::Engine::Server (marked as Deprecated)
414 =item Catalyst::Engine::HTTP::POE (marked as Deprecated)
418 =head2 Plack functionality
420 See L<Catalyst::PSGI>.
424 Tests should generally work the same in Catalyst 5.9, but there are
427 Previously, if using L<Catalyst::Test> and doing local requests (against
428 a local server), if the application threw an exception then this
429 exception propagated into the test.
431 This behavior has been removed, and now a 500 response will be returned
432 to the test. This change standardizes behavior, so that local test
433 requests behave similarly to remote requests.
435 =head1 Upgrading to Catalyst 5.80
437 Most applications and plugins should run unaltered on Catalyst 5.80.
439 However, a lot of refactoring work has taken place, and several changes have
440 been made which could cause incompatibilities. If your application or plugin
441 is using deprecated code, or relying on side effects, then you could have
442 issues upgrading to this release.
444 Most issues found with existing components have been easy to
445 solve. This document provides a complete description of behavior changes
446 which may cause compatibility issues, and of new Catalyst warnings which
449 If you think you have found an upgrade-related issue which is not covered in
450 this document, please email the Catalyst list to discuss the problem.
452 =head1 Moose features
454 =head2 Application class roles
456 You can only apply method modifiers after the application's C<< ->setup >>
457 method has been called. This means that modifiers will not work with methods
458 run during the call to C<< ->setup >>.
460 See L<Catalyst::Manual::ExtendingCatalyst> for more information about using
461 L<Moose> in your applications.
463 =head2 Controller actions in Moose roles
465 You can use L<MooseX::MethodAttributes::Role> if you want to declare actions
468 =head2 Using Moose in Components
470 The correct way to use Moose in a component in a both forward and backwards
473 package TestApp::Controller::Root;
475 BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
477 See L<Components which inherit from Moose::Object before Catalyst::Component>.
479 =head1 Known backwards compatibility breakages
481 =head2 Applications in a single file
483 Applications must be in their own file, and loaded at compile time. This
484 issue generally only affects the tests of CPAN distributions. Your
485 application will fail if you try to define an application inline in a
486 block, and use plugins which supply a C< new > method, then use that
487 application latter in tests within the same file.
489 This is due to the fact that Catalyst is inlining a new method on your
490 application class allowing it to be compatible with Moose. The method
491 used to do this changed in 5.80004 to avoid the possibility of reporting
492 an 'Unknown Error' if your application failed to compile.
494 =head2 Issues with Class::C3
496 Catalyst 5.80 uses the L<Algorithm::C3> method dispatch order. This is
497 built into Perl 5.10, and comes via L<Class::C3> for Perl 5.8. This
498 replaces L<NEXT> with L<Class::C3::Adopt::NEXT>, forcing all components
499 to resolve methods using C3, rather than the unpredictable dispatch
502 This issue manifests itself by your application failing to start due to an
503 error message about having a non-linear @ISA.
505 The Catalyst plugin most often causing this is
506 L<Catalyst::Plugin::Session::Store::FastMmap> - if you are using this
507 plugin and see issues, then please upgrade your plugins, as it has been
508 fixed. Note that Makefile.PL in the distribution will warn about known
509 incompatible components.
511 This issue can, however, be found in your own application - the only solution is
512 to go through each base class of the class the error was reported against, until
513 you identify the ones in conflict, and resolve them.
515 To be able to generate a linear @ISA, the list of superclasses for each
516 class must be resolvable using the C3 algorithm. Unfortunately, when
517 superclasses are being used as mixins (to add functionality used in your class),
518 and with multiple inheritance, it is easy to get this wrong.
520 Most common is the case of:
522 package Component1; # Note, this is the common case
523 use base qw/Class::Accessor::Fast Class::Data::Inheritable/;
525 package Component2; # Accidentally saying it this way causes a failure
526 use base qw/Class::Data::Inheritable Class::Accessor::Fast/;
529 use base qw/Component1 Component2/;
531 Any situation like this will cause your application to fail to start.
533 For additional documentation about this issue, and how to resolve it, see
534 L<Class::C3::Adopt::NEXT>.
536 =head2 Components which inherit from Moose::Object before Catalyst::Component
538 Moose components which say:
540 package TestApp::Controller::Example;
542 extends qw/Moose::Object Catalyst::Component/;
544 to use the constructor provided by Moose, while working (if you do some hacks
545 with the C< BUILDARGS > method), will not work with Catalyst 5.80 as
546 C<Catalyst::Component> inherits from C<Moose::Object>, and so C< @ISA > fails
549 The correct way to use Moose in a component in a both forward and backwards
552 package TestApp::Controller::Root;
554 BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
556 Note that the C< extends > declaration needs to occur in a begin block for
557 L<attributes> to operate correctly.
559 This way you do not inherit directly from C<Moose::Object>
560 yourself. Having components which do not inherit their constructor from
561 C<Catalyst::Component> is B<unsupported>, and has never been recommended,
562 therefore you're on your own if you're using this technique. You'll need
563 to detect the version of Catalyst your application is running, and deal
564 with it appropriately.
566 You also don't get the L<Moose::Object> constructor, and therefore attribute
567 initialization will not work as normally expected. If you want to use Moose
568 attributes, then they need to be made lazy to correctly initialize.
570 Note that this only applies if your component needs to maintain component
571 backwards compatibility for Catalyst versions before 5.71001 - in 5.71001
572 attributes work as expected, and the BUILD method is called normally
573 (although BUILDARGS is not).
575 If you depend on Catalyst 5.8, then B<all> Moose features work as expected.
577 You will also see this issue if you do the following:
579 package TestApp::Controller::Example;
581 use base 'Catalyst::Controller';
583 as C< use base > appends to @ISA.
585 =head3 use Moose in MyApp
587 Similar to the above, this will also fail:
596 If you need to use Moose in your application class (e.g. for method modifiers
597 etc.) then the correct technique is:
605 __PACKAGE__->config( name => 'MyApp' );
606 __PACKAGE__->setup(qw/
610 =head2 Anonymous closures installed directly into the symbol table
612 If you have any code which installs anonymous subroutine references directly
613 into the symbol table, you may encounter breakages. The simplest solution is
614 to use L<Sub::Name> to name the subroutine. Example:
616 # Original code, likely to break:
617 my $full_method_name = join('::', $package_name, $method_name);
618 *$full_method_name = sub { ... };
621 use Sub::Name 'subname';
622 my $full_method_name = join('::',$package_name, $method_name);
623 *$full_method_name = subname $full_method_name, sub { ... };
625 Additionally, you can take advantage of Catalyst's use of L<Class::MOP> and
626 install the closure using the appropriate metaclass. Example:
629 my $metaclass = Moose::Meta::Class->initialize($package_name);
630 $metaclass->add_method($method_name => sub { ... });
632 =head2 Hooking into application setup
634 To execute code during application start-up, the following snippet in MyApp.pm
638 my ($class, @args) = @_;
639 $class->NEXT::setup(@args);
640 ... # things to do after the actual setup
643 With Catalyst 5.80 this won't work anymore, because Catalyst no longer
644 uses NEXT.pm for method resolution. The functionality was only ever
645 originally operational as L<NEXT> remembers what methods have already
646 been called, and will not call them again.
648 Using this now causes infinite recursion between MyApp::setup and
649 Catalyst::setup, due to other backwards compatibility issues related to how
650 plugin setup works. Moose method modifiers like C<< before|after|around setup
651 => sub { ... }; >> also will not operate correctly on the setup method.
653 The right way to do it is this:
655 after setup_finalize => sub {
656 ... # things to do after the actual setup
659 The setup_finalize hook was introduced as a way to avoid this issue.
661 =head2 Components with a new method which returns false
663 Previously, if you had a component which inherited from Catalyst::COMPONENT,
664 but overrode the new method to return false, then your class's configuration
665 would be blessed into a hash on your behalf, and this would be returned from
666 the COMPONENT method.
668 This behavior makes no sense, and so has been removed. Implementing your own
669 C< new > method in components is B<highly> discouraged. Instead, you should
670 inherit the new method from Catalyst::Component, and use Moose's BUILD
671 functionality and/or Moose attributes to perform any construction work
672 necessary for your class.
674 =head2 __PACKAGE__->mk_accessor('meta');
676 Won't work due to a limitation of L<Moose>. This is currently being fixed
679 =head2 Class::Data::Inheritable side effects
681 Previously, writing to a class data accessor would copy the accessor method
682 down into your package.
684 This behavior has been removed. While the class data is still stored
685 per-class, it is stored on the metaclass of the class defining the accessor.
687 Therefore anything relying on the side effect of the accessor being copied down
690 The following test demonstrates the problem:
694 use base qw/Class::Data::Inheritable/;
695 __PACKAGE__->mk_classdata('foo');
700 use base qw/BaseClass/;
703 BaseClass->foo('base class');
704 Child->foo('sub class');
707 isnt(BaseClass->can('foo'), Child->can('foo'));
709 =head2 Extending Catalyst::Request or other classes in an ad hoc manner using mk_accessors
711 Previously, it was possible to add additional accessors to Catalyst::Request
712 (or other classes) by calling the mk_accessors class method.
714 This is no longer supported - users should make a subclass of the class whose
715 behavior they would like to change, rather than globally polluting the
718 =head2 Confused multiple inheritance with Catalyst::Component::COMPONENT
720 Previously, Catalyst's COMPONENT method would delegate to the method on
721 the right hand side, which could then delegate back again with
722 NEXT. This is poor practice, and in addition, makes no sense with C3
723 method dispatch order, and is therefore no longer supported.
725 If a COMPONENT method is detected in the inheritance hierarchy to the right
726 hand side of Catalyst::Component::COMPONENT, then the following warning
727 message will be emitted:
729 There is a COMPONENT method resolving after Catalyst::Component
732 The correct fix is to re-arrange your class's inheritance hierarchy so that the
733 COMPONENT method you would like to inherit is the first (left-hand most)
734 COMPONENT method in your @ISA.
736 =head2 Development server relying on environment variables
738 Previously, the development server would allow propagation of system
739 environment variables into the request environment, this has changed with the
740 adoption of Plack. You can use L<Plack::Middleware::ForceEnv> to achieve the
745 =head2 Actions in your application class
747 Having actions in your application class will now emit a warning at application
748 startup as this is deprecated. It is highly recommended that these actions are moved
749 into a MyApp::Controller::Root (as demonstrated by the scaffold application
750 generated by catalyst.pl).
752 This warning, also affects tests. You should move actions in your test,
753 creating a myTest::Controller::Root, like the following example:
755 package MyTest::Controller::Root;
760 use parent 'Catalyst::Controller';
762 __PACKAGE__->config(namespace => '');
765 my ( $self, $c ) = @_;
771 =head2 ::[MVC]:: naming scheme
773 Having packages called MyApp::[MVC]::XX is deprecated and can no longer be generated
776 This is still supported, but it is recommended that you rename your application
777 components to Model/View/Controller.
779 A warning will be issued at application startup if the ::[MVC]:: naming scheme is
782 =head2 Catalyst::Base
784 Any code using L<Catalyst::Base> will now emit a warning; this
785 module will be removed in a future release.
787 =head2 Methods in Catalyst::Dispatcher
789 The following methods in Catalyst::Dispatcher are implementation
790 details, which may change in the 5.8X release series, and therefore their use
791 is highly deprecated.
799 =item registered_dispatch_types
801 =item method_action_class
809 The first time one of these methods is called, a warning will be emitted:
811 Class $class is calling the deprecated method Catalyst::Dispatcher::$public_method_name,
812 this will be removed in Catalyst 5.9
814 You should B<NEVER> be calling any of these methods from application code.
816 Plugin authors and maintainers whose plugins currently call these methods
817 should change to using the public API, or, if you do not feel the public API
818 adequately supports your use case, please email the development list to
819 discuss what API features you need so that you can be appropriately supported.
821 =head2 Class files with names that don't correspond to the packages they define
823 In this version of Catalyst, if a component is loaded from disk, but no
824 symbols are defined in that component's name space after it is loaded, this
825 warning will be issued:
827 require $class was successful but the package is not defined.
829 This is to protect against confusing bugs caused by mistyping package names,
830 and will become a fatal error in a future version.
832 Please note that 'inner packages' (via L<Devel::InnerPackage>) are still fully
833 supported; this warning is only issued when component file naming does not map
834 to B<any> of the packages defined within that component.
836 =head2 $c->plugin method
838 Calling the plugin method is deprecated, and calling it at run time is B<highly
841 Instead you are recommended to use L<Catalyst::Model::Adaptor> or similar to
842 compose the functionality you need outside of the main application name space.
844 Calling the plugin method will not be supported past Catalyst 5.81.