3 Catalyst::Upgrading - Instructions for upgrading to the latest Catalyst
5 =head1 Upgrading to Catalyst 5.90097
7 In older versions of Catalyst one could construct a L<URI> with a fragment (such as
8 https://localhost/foo/bar#fragment) by using a '#' in the path or final argument, for
11 $c->uri_for('/mypath#fragment');
15 $c->uri_for($action, 'foo#fragment');
17 This behavior was never documented and would break if using the Unicode plugin, or when
18 adding a query to the arguments:
20 $c->uri_for($action, 'foo#fragment', +{ a=>1, b=>2});
22 would define a fragment like "#fragment?a=1&b=2".
24 When we introduced UTF-8 encoding by default in Catalyst 5.9008x this side effect behavior
25 was broken since we started encoding the '#' when it was part of the URI path.
27 In version 5.90095 and 5.90096 we attempted to fix this, but all we managed to do was break
28 people with URIs that included '#' as part of the path data, when it was not expected to
29 be a fragment delimiter.
31 In general L<Catalyst> prefers an explicit specification rather than relying on side effects
32 or domain specific mini languages. As a result we are now defining how to set a fragment
33 for a URI via ->uri_for:
35 $c->uri_for($action_or_path, \@captures_or_args, @args, \$query, \$fragment);
37 If you are relying on the previous side effect behavior your URLs will now encode the '#'
38 delimiter, which is going to be a breaking change for you. You need to alter your code
39 to match the new specification or modify uri_for for your local case. Patches to solve
40 this are very welcomed, as long as they don't break existing test cases.
42 B<NOTE> If you are using the alternative:
44 $c->uri_for('/foo/bar#baz')
46 construction, we do not attempt to encode this and it will make a URL with a
50 =head1 Upgrading to Catalyst 5.90095
52 The method C<last_error> in L</Catalyst> was actually returning the first error. This has
53 been fixed but there is a small chance it could be a breaking issue for you. If this gives
54 you trouble changing to C<shift_errors> is the easiest workaround (although that does
55 modify the error stack so if you are relying on that not being changed you should try something
56 like @{$c->errors}[-1] instead. Since this method is relatively new and the cases when the
57 error stack actually has more than one error in it, we feel the exposure is very low, but bug
58 reports are very welcomed.
60 =head1 Upgrading to Catalyst 5.90090
62 L<Catalyst::Utils> has a new method 'inject_component' which works the same as the method of
63 the same name in L<CatalystX::InjectComponent>. You should start converting any
64 use of the non core method in your code as future changes to Catalyst will be
65 sychronized to the core method first. We reserve the right to cease support
66 of the non core version should we reach a point in time where it cannot be
67 properly supported as an external module. Luckily this should be a trivial
68 search and replace. Change all occurances of:
70 CatalystX::InjectComponent->inject(...)
74 Catalyst::Utils::inject_component(...)
76 and we expect everything to work the same (we'd consider it not working the same
77 to be a bug, and please report it.)
79 We also cored features from L<CatalystX::RoleApplicator> to compose a role into the
80 request, response and stats classes. The main difference is that with L<CatalystX::RoleApplicator>
86 use CatalystX::RoleApplicator;
88 __PACKAGE__->apply_request_class_roles(
89 qw/My::Request::Role Other::Request::Role/);
91 Whereas now we have three class attributes, 'request_class_traits', 'response_class_traits'
92 and 'stats_class_traits', so you use like this (note this value is an ArrayRef)
99 __PACKAGE__->request_class_traits([qw/
101 Other::Request::Role/]);
103 (And the same for response_class_traits and stats_class_traits. We left off the
104 traits for Engine, since that class does a lot less nowadays, and dispatcher. If you
105 used those and can share a use case, we'd be likely to support them.
107 Lastly, we have some of the feature from L<CatalystX::ComponentsFromConfig> in
108 core. This should mostly work the same way in core, except for now the
109 core version does not create an automatic base wrapper class for your configured
110 components (it requires these to be catalyst components and injects them directly.
111 So if you make heavy use of custom base classes in L<CatalystX::ComponentsFromConfig>
112 you might need a bit of work to use the core version (although there is no reason
113 to stop using L<CatalystX::ComponentsFromConfig> since it should continue to work
114 fine and we'd consider issues with it to be bugs). Here's one way to map from
115 L<CatalystX::ComponentsFromConfig> to core:
117 In L<CatalystX::ComponentsFromConfig>:
120 'Model::MyClass' => {
129 inject_components => {
130 'Model::MyClass' => { from_component => 'My::Class' },
132 'Model::MyClass' => {
137 Although the cored behavior requires more code, its better separates concerns
138 as well as plays more into core Catalyst expections of how configuration shoul
141 Also we added a new develop console mode only warning when you call a component
142 with arguments that don't expect or do anything meaningful with those args. Its
143 possible if you are logging debug mode in production (please don't...) this
144 could add verbosity to those logs if you also happen to be calling for components
145 and passing pointless arguments. We added this warning to help people not make this
146 error and to better understand the component resolution flow.
148 =head1 Upgrading to Catalyst 5.90085
150 In this version of Catalyst we made a small change to Chained Dispatching so
151 that when two or more actions all have the same path specification AND they
152 all have Args(0), we break the tie by choosing the last action defined, and
153 not the first one defined. This was done to normalize Chaining to following
154 the 'longest Path wins, and when several actions match the same Path specification
155 we choose the last defined.' rule. Previously Args(0) was hard coded to be a special
156 case such that the first action defined would match (which is not the case when
159 Its possible that this could be a breaking change for you, if you had used
160 action roles (custom or otherwise) to add additional matching rules to differentiate
161 between several Args(0) actions that share the same root action chain. For
162 example if you have code now like this:
164 sub check_default :Chained(/) CaptureArgs(0) { ... }
166 sub default_get :Chained('check_default') PathPart('') Args(0) GET {
167 pop->res->body('get3');
170 sub default_post :Chained('check_default') PathPart('') Args(0) POST {
171 pop->res->body('post3');
174 sub chain_default :Chained('check_default') PathPart('') Args(0) {
175 pop->res->body('chain_default');
178 The way that chaining will work previous is that when two or more equal actions can
179 match, the 'top' one wins. So if the request is "GET .../check_default" BOTH
180 actions 'default_get' AND 'chain_default' would match. To break the tie in
181 the case when Args is 0, we'd previous take the 'top' (or first defined) action.
182 Unfortunately this treatment of Args(0) is special case. In all other cases
183 we choose the 'last defined' action to break a tie. So this version of
184 Catalyst changed the dispatcher to make Args(0) no longer a special case for
185 breaking ties. This means that the above code must now become:
187 sub check_default :Chained(/) CaptureArgs(0) { ... }
189 sub chain_default :Chained('check_default') PathPart('') Args(0) {
190 pop->res->body('chain_default');
193 sub default_get :Chained('check_default') PathPart('') Args(0) GET {
194 pop->res->body('get3');
197 sub default_post :Chained('check_default') PathPart('') Args(0) POST {
198 pop->res->body('post3');
201 If we want it to work as expected (for example we we GET to match 'default_get' and
202 POST to match 'default_post' and any other http Method to match 'chain_default').
204 In other words Arg(0) and chained actions must now follow the normal rule where
205 in a tie the last defined action wins and you should place all your less defined
206 or 'catch all' actions first.
208 If this causes you trouble and you can't fix your code to conform, you may set the
209 application configuration setting "use_chained_args_0_special_case" to true and
210 that will revert you code to the previous behavior.
212 =head2 More backwards compatibility options with UTF-8 changes
214 In order to give better backwards compatiblity with the 5.90080+ UTF-8 changes
215 we've added several configuration options around control of how we try to decode
216 your URL keywords / query parameters.
218 C<do_not_decode_query>
220 If true, then do not try to character decode any wide characters in your
221 request URL query or keywords. Most readings of the relevent specifications
222 suggest these should be UTF-* encoded, which is the default that L<Catalyst>
223 will use, hwoever if you are creating a lot of URLs manually or have external
224 evil clients, this might cause you trouble. If you find the changes introduced
225 in Catalyst version 5.90080+ break some of your query code, you may disable
226 the UTF-8 decoding globally using this configuration.
228 This setting takes precedence over C<default_query_encoding> and
229 C<decode_query_using_global_encoding>
231 C<default_query_encoding>
233 By default we decode query and keywords in your request URL using UTF-8, which
234 is our reading of the relevent specifications. This setting allows one to
235 specify a fixed value for how to decode your query. You might need this if
236 you are doing a lot of custom encoding of your URLs and not using UTF-8.
238 This setting take precedence over C<decode_query_using_global_encoding>.
240 C<decode_query_using_global_encoding>
242 Setting this to true will default your query decoding to whatever your
243 general global encoding is (the default is UTF-8).
246 =head1 Upgrading to Catalyst 5.90080
248 UTF8 encoding is now default. For temporary backwards compatibility, if this
249 change is causing you trouble, you can disable it by setting the application
250 configuration option to undef:
252 MyApp->config(encoding => undef);
254 But please consider this a temporary measure since it is the intention that
255 UTF8 is enabled going forwards and the expectation is that other ecosystem
256 projects will assume this as well. At some point you application will not
257 correctly function without this setting.
259 As of 5.90084 we've added two additional configuration flags for more selective
260 control over some encoding changes: 'skip_body_param_unicode_decoding' and
261 'skip_complex_post_part_handling'. You may use these to more selectively
262 disable new features while you are seeking a long term fix. Please review
263 CONFIGURATION in L<Catalyst>.
265 For further information, please see L<Catalyst::UTF8>
267 A number of projects in the wider ecosystem required minor updates to be able
268 to work correctly. Here's the known list:
270 L<Catalyst::View::TT>, L<Catalyst::View::Mason>, L<Catalyst::View::HTML::Mason>,
271 L<Catalyst::View::Xslate>, L<Test::WWW::Mechanize::Catalyst>
273 You will need to update to modern versions in most cases, although quite a few
274 of these only needed minor test case and documentation changes so you will need
275 to review the changelog of each one that is relevant to you to determine your
278 =head1 Upgrading to Catalyst 5.90060
280 Starting in the v5.90059_001 development release, the regexp dispatch type is
281 no longer automatically included as a dependency. If you are still using this
282 dispatch type, you need to add L<Catalyst::DispatchType::Regex> into your build
285 The standalone distribution of Regexp will be supported for the time being, but
286 should we find that supporting it prevents us from moving L<Catalyst> forward
287 in necessary ways, we reserve the right to drop that support. It is highly
288 recommended that you use this last stage of deprecation to change your code.
290 =head1 Upgrading to Catalyst 5.90040
292 =head2 Catalyst::Plugin::Unicode::Encoding is now core
294 The previously stand alone Unicode support module L<Catalyst::Plugin::Unicode::Encoding>
295 has been brought into core as a default plugin. Going forward, all you need is
296 to add a configuration setting for the encoding type. For example:
302 __PACKAGE__->config( encoding => 'UTF-8' );
304 Please note that this is different from the old stand alone plugin which applied
305 C<UTF-8> encoding by default (that is, if you did not set an explicit
306 C<encoding> configuration value, it assumed you wanted UTF-8). In order to
307 preserve backwards compatibility you will need to explicitly turn it on via the
308 configuration setting. THIS MIGHT CHANGE IN THE FUTURE, so please consider
309 starting to test your application with proper UTF-8 support and remove all those
310 crappy hacks you munged into the code because you didn't know the Plugin
313 For people that are using the Plugin, you will note a startup warning suggesting
314 that you can remove it from the plugin list. When you do so, please remember to
315 add the configuration setting, since you can no longer rely on the default being
316 UTF-8. We'll add it for you if you continue to use the stand alone plugin and
317 we detect this, but this backwards compatibility shim will likely be removed in
318 a few releases (trying to clean up the codebase after all).
320 If you have trouble with any of this, please bring it to the attention of the
321 Catalyst maintainer group.
323 =head2 basic async and event loop support
325 This version of L<Catalyst> offers some support for using L<AnyEvent> and
326 L<IO::Async> event loops in your application. These changes should work
327 fine for most applications however if you are already trying to perform
328 some streaming, minor changes in this area of the code might affect your
329 functionality. Please see L<Catalyst::Response\write_fh> for more and for a
332 We consider this feature experimental. We will try not to break it, but we
333 reserve the right to make necessary changes to fix major issues that people
334 run into when the use this functionality in the wild.
336 =head1 Upgrading to Catalyst 5.90030
338 =head2 Regex dispatch type is deprecated.
340 The Regex dispatchtype (L<Catalyst::DispatchType::Regex>) has been deprecated.
342 You are encouraged to move your application to Chained dispatch (L<Catalyst::DispatchType::Chained>).
344 If you cannot do so, please add a dependency to Catalyst::DispatchType::Regex to your application's
347 =head1 Upgrading to Catalyst 5.9
349 The major change is that L<Plack>, a toolkit for using the L<PSGI>
350 specification, now replaces most of the subclasses of L<Catalyst::Engine>. If
351 you are using one of the standard subclasses of L<Catalyst::Engine> this
352 should be a straightforward upgrade for you. It was a design goal for
353 this release to preserve as much backwards compatibility as possible.
354 However, since L<Plack> is different from L<Catalyst::Engine>, it is
355 possible that differences exist for edge cases. Therefore, we recommend
356 that care be taken with this upgrade and that testing should be greater
357 than would be the case with a minor point update. Please inform the
358 Catalyst developers of any problems so that we can fix them and
361 It is highly recommended that you become familiar with the L<Plack> ecosystem
362 and documentation. Being able to take advantage of L<Plack> development and
363 middleware is a major bonus to this upgrade. Documentation about how to
364 take advantage of L<Plack::Middleware> by writing your own C<< .psgi >> file
365 is contained in L<Catalyst::PSGI>.
367 If you have created a custom subclass of L<Catalyst:Engine>, you will
368 need to convert it to be a subclass of L<Plack::Handler>.
370 If you are using the L<Plack> engine, L<Catalyst::Engine::PSGI>, this new
371 release supersedes that code.
373 If you are using a subclass of L<Catalyst::Engine> that is aimed at
374 nonstandard or internal/testing uses, such as
375 L<Catalyst::Engine::Embeddable>, you should still be able to continue
378 Advice for specific subclasses of L<Catalyst::Engine> follows:
380 =head2 Upgrading the FastCGI Engine
382 No upgrade is needed if your myapp_fastcgi.pl script is already upgraded
383 to use L<Catalyst::Script::FastCGI>.
385 =head2 Upgrading the mod_perl / Apache Engines
387 The engines that are built upon the various iterations of mod_perl,
388 L<Catalyst::Engine::Apache::MP13> (for mod_perl 1, and Apache 1.x) and
389 L<Catalyst::Engine::Apache2::MP20> (for mod_perl 2, and Apache 2.x),
390 should be seamless upgrades and will work using L<Plack::Handler::Apache1>
391 or L<Plack::Handler::Apache2> as required.
393 L<Catalyst::Engine::Apache2::MP19>, however, is no longer supported, as
394 Plack does not support mod_perl version 1.99. This is unlikely to be a
395 problem for anyone, as 1.99 was a brief beta-test release for mod_perl
396 2, and all users of mod_perl 1.99 are encouraged to upgrade to a
397 supported release of Apache 2 and mod_perl 2.
399 =head2 Upgrading the HTTP Engine
401 The default development server that comes with the L<Catalyst> distribution
402 should continue to work as expected with no changes as long as your C<myapp_server>
403 script is upgraded to use L<Catalyst::Script::HTTP>.
405 =head2 Upgrading the CGI Engine
407 If you were using L<Catalyst::Engine::CGI> there is no upgrade needed if your
408 myapp_cgi.pl script is already upgraded to use L<Catalyst::Script::CGI>.
410 =head2 Upgrading Catalyst::Engine::HTTP::Prefork
412 If you were using L<Catalyst::Engine::HTTP::Prefork> then L<Starman>
413 is automatically loaded. You should (at least) change your C<Makefile.PL>
414 to depend on Starman.
416 You can regenerate your C<myapp_server.pl> script with C<catalyst.pl>
417 and implement a C<MyApp::Script::Server> class that looks like this:
419 package MyApp::Script::Server;
421 use namespace::autoclean;
423 extends 'CatalystX::Script::Server::Starman';
427 This takes advantage of the new script system, and will add a number of
428 options to the standard server script as extra options are added by
431 More information about these options can be seen at
432 L<CatalystX::Script::Server::Starman/SYNOPSIS>.
434 An alternate route to implement this functionality is to write a simple .psgi
435 file for your application, and then use the L<plackup> utility to start the
438 =head2 Upgrading the PSGI Engine
440 If you were using L<Catalyst::Engine::PSGI>, this new release supersedes
441 this engine in supporting L<Plack>. By default the Engine is now always
442 L<Plack>. As a result, you can remove the dependency on
443 L<Catalyst::Engine::PSGI> in your C<Makefile.PL>.
445 Applications that were using L<Catalyst::Engine::PSGI>
446 previously should entirely continue to work in this release with no changes.
448 However, if you have an C<app.psgi> script, then you no longer need to
449 specify the PSGI engine. Instead, the L<Catalyst> application class now
450 has a new method C<psgi_app> which returns a L<PSGI> compatible coderef
451 which you can wrap in the middleware of your choice.
453 Catalyst will use the .psgi for your application if it is located in the C<home>
454 directory of the application.
456 For example, if you were using L<Catalyst::Engine::PSGI> in the past, you will
457 have written (or generated) a C<script/myapp.psgi> file similar to this one:
462 MyCatalystApp->setup_engine('PSGI');
465 enable ... # enable your desired middleware
466 sub { MyCatalystApp->run(@_) };
469 Instead, you now say:
475 enable ... #enable your desired middleware
476 MyCatalystApp->psgi_app;
479 In the simplest case:
481 MyCatalystApp->setup_engine('PSGI');
482 my $app = sub { MyCatalystApp->run(@_) }
486 my $app = MyCatalystApp->psgi_app(@_);
490 my $app = sub { MyCatalystApp->psgi_app(@_) };
491 # If you make ^^ this mistake, your app won't work, and will confuse the hell out of you!
493 You can now move C<< script/myapp.psgi >> to C<< myapp.psgi >>, and the built-in
494 Catalyst scripts and your test suite will start using your .psgi file.
496 B<NOTE:> If you rename your .psgi file without these modifications, then
497 any tests run via L<Catalyst::Test> will not be compatible with the new
498 release, and will result in the development server starting, rather than
499 the expected test running.
501 B<NOTE:> If you are directly accessing C<< $c->req->env >> to get the PSGI
502 environment then this accessor is moved to C<< $c->engine->env >>,
503 you will need to update your code.
505 =head2 Engines which are known to be broken
507 The following engines B<DO NOT> work as of Catalyst version 5.9. The
508 core team will be happy to work with the developers and/or users of
509 these engines to help them port to the new Plack/Engine system, but for
510 now, applications which are currently using these engines B<WILL NOT>
511 run without modification to the engine code.
515 =item Catalyst::Engine::Wx
517 =item Catalyst::Engine::Zeus
519 =item Catalyst::Engine::JobQueue::POE
521 =item Catalyst::Engine::XMPP2
523 =item Catalyst::Engine::SCGI
527 =head2 Engines with unknown status
529 The following engines are untested or have unknown compatibility.
530 Reports are highly encouraged:
534 =item Catalyst::Engine::Mojo
536 =item Catalyst::Engine::Server (marked as Deprecated)
538 =item Catalyst::Engine::HTTP::POE (marked as Deprecated)
542 =head2 Plack functionality
544 See L<Catalyst::PSGI>.
548 Tests should generally work the same in Catalyst 5.9, but there are
551 Previously, if using L<Catalyst::Test> and doing local requests (against
552 a local server), if the application threw an exception then this
553 exception propagated into the test.
555 This behavior has been removed, and now a 500 response will be returned
556 to the test. This change standardizes behavior, so that local test
557 requests behave similarly to remote requests.
559 =head1 Upgrading to Catalyst 5.80
561 Most applications and plugins should run unaltered on Catalyst 5.80.
563 However, a lot of refactoring work has taken place, and several changes have
564 been made which could cause incompatibilities. If your application or plugin
565 is using deprecated code, or relying on side effects, then you could have
566 issues upgrading to this release.
568 Most issues found with existing components have been easy to
569 solve. This document provides a complete description of behavior changes
570 which may cause compatibility issues, and of new Catalyst warnings which
573 If you think you have found an upgrade-related issue which is not covered in
574 this document, please email the Catalyst list to discuss the problem.
576 =head1 Moose features
578 =head2 Application class roles
580 You can only apply method modifiers after the application's C<< ->setup >>
581 method has been called. This means that modifiers will not work with methods
582 run during the call to C<< ->setup >>.
584 See L<Catalyst::Manual::ExtendingCatalyst> for more information about using
585 L<Moose> in your applications.
587 =head2 Controller actions in Moose roles
589 You can use L<MooseX::MethodAttributes::Role> if you want to declare actions
592 =head2 Using Moose in Components
594 The correct way to use Moose in a component in a both forward and backwards
597 package TestApp::Controller::Root;
599 BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
601 See L<Components which inherit from Moose::Object before Catalyst::Component>.
603 =head1 Known backwards compatibility breakages
605 =head2 Applications in a single file
607 Applications must be in their own file, and loaded at compile time. This
608 issue generally only affects the tests of CPAN distributions. Your
609 application will fail if you try to define an application inline in a
610 block, and use plugins which supply a C< new > method, then use that
611 application latter in tests within the same file.
613 This is due to the fact that Catalyst is inlining a new method on your
614 application class allowing it to be compatible with Moose. The method
615 used to do this changed in 5.80004 to avoid the possibility of reporting
616 an 'Unknown Error' if your application failed to compile.
618 =head2 Issues with Class::C3
620 Catalyst 5.80 uses the L<Algorithm::C3> method dispatch order. This is
621 built into Perl 5.10, and comes via L<Class::C3> for Perl 5.8. This
622 replaces L<NEXT> with L<Class::C3::Adopt::NEXT>, forcing all components
623 to resolve methods using C3, rather than the unpredictable dispatch
626 This issue manifests itself by your application failing to start due to an
627 error message about having a non-linear @ISA.
629 The Catalyst plugin most often causing this is
630 L<Catalyst::Plugin::Session::Store::FastMmap> - if you are using this
631 plugin and see issues, then please upgrade your plugins, as it has been
632 fixed. Note that Makefile.PL in the distribution will warn about known
633 incompatible components.
635 This issue can, however, be found in your own application - the only solution is
636 to go through each base class of the class the error was reported against, until
637 you identify the ones in conflict, and resolve them.
639 To be able to generate a linear @ISA, the list of superclasses for each
640 class must be resolvable using the C3 algorithm. Unfortunately, when
641 superclasses are being used as mixins (to add functionality used in your class),
642 and with multiple inheritance, it is easy to get this wrong.
644 Most common is the case of:
646 package Component1; # Note, this is the common case
647 use base qw/Class::Accessor::Fast Class::Data::Inheritable/;
649 package Component2; # Accidentally saying it this way causes a failure
650 use base qw/Class::Data::Inheritable Class::Accessor::Fast/;
653 use base qw/Component1 Component2/;
655 Any situation like this will cause your application to fail to start.
657 For additional documentation about this issue, and how to resolve it, see
658 L<Class::C3::Adopt::NEXT>.
660 =head2 Components which inherit from Moose::Object before Catalyst::Component
662 Moose components which say:
664 package TestApp::Controller::Example;
666 extends qw/Moose::Object Catalyst::Component/;
668 to use the constructor provided by Moose, while working (if you do some hacks
669 with the C< BUILDARGS > method), will not work with Catalyst 5.80 as
670 C<Catalyst::Component> inherits from C<Moose::Object>, and so C< @ISA > fails
673 The correct way to use Moose in a component in a both forward and backwards
676 package TestApp::Controller::Root;
678 BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
680 Note that the C< extends > declaration needs to occur in a begin block for
681 L<attributes> to operate correctly.
683 This way you do not inherit directly from C<Moose::Object>
684 yourself. Having components which do not inherit their constructor from
685 C<Catalyst::Component> is B<unsupported>, and has never been recommended,
686 therefore you're on your own if you're using this technique. You'll need
687 to detect the version of Catalyst your application is running, and deal
688 with it appropriately.
690 You also don't get the L<Moose::Object> constructor, and therefore attribute
691 initialization will not work as normally expected. If you want to use Moose
692 attributes, then they need to be made lazy to correctly initialize.
694 Note that this only applies if your component needs to maintain component
695 backwards compatibility for Catalyst versions before 5.71001 - in 5.71001
696 attributes work as expected, and the BUILD method is called normally
697 (although BUILDARGS is not).
699 If you depend on Catalyst 5.8, then B<all> Moose features work as expected.
701 You will also see this issue if you do the following:
703 package TestApp::Controller::Example;
705 use base 'Catalyst::Controller';
707 as C< use base > appends to @ISA.
709 =head3 use Moose in MyApp
711 Similar to the above, this will also fail:
720 If you need to use Moose in your application class (e.g. for method modifiers
721 etc.) then the correct technique is:
729 __PACKAGE__->config( name => 'MyApp' );
730 __PACKAGE__->setup(qw/
734 =head2 Anonymous closures installed directly into the symbol table
736 If you have any code which installs anonymous subroutine references directly
737 into the symbol table, you may encounter breakages. The simplest solution is
738 to use L<Sub::Name> to name the subroutine. Example:
740 # Original code, likely to break:
741 my $full_method_name = join('::', $package_name, $method_name);
742 *$full_method_name = sub { ... };
745 use Sub::Name 'subname';
746 my $full_method_name = join('::',$package_name, $method_name);
747 *$full_method_name = subname $full_method_name, sub { ... };
749 Additionally, you can take advantage of Catalyst's use of L<Class::MOP> and
750 install the closure using the appropriate metaclass. Example:
753 my $metaclass = Moose::Meta::Class->initialize($package_name);
754 $metaclass->add_method($method_name => sub { ... });
756 =head2 Hooking into application setup
758 To execute code during application start-up, the following snippet in MyApp.pm
762 my ($class, @args) = @_;
763 $class->NEXT::setup(@args);
764 ... # things to do after the actual setup
767 With Catalyst 5.80 this won't work anymore, because Catalyst no longer
768 uses NEXT.pm for method resolution. The functionality was only ever
769 originally operational as L<NEXT> remembers what methods have already
770 been called, and will not call them again.
772 Using this now causes infinite recursion between MyApp::setup and
773 Catalyst::setup, due to other backwards compatibility issues related to how
774 plugin setup works. Moose method modifiers like C<< before|after|around setup
775 => sub { ... }; >> also will not operate correctly on the setup method.
777 The right way to do it is this:
779 after setup_finalize => sub {
780 ... # things to do after the actual setup
783 The setup_finalize hook was introduced as a way to avoid this issue.
785 =head2 Components with a new method which returns false
787 Previously, if you had a component which inherited from Catalyst::COMPONENT,
788 but overrode the new method to return false, then your class's configuration
789 would be blessed into a hash on your behalf, and this would be returned from
790 the COMPONENT method.
792 This behavior makes no sense, and so has been removed. Implementing your own
793 C< new > method in components is B<highly> discouraged. Instead, you should
794 inherit the new method from Catalyst::Component, and use Moose's BUILD
795 functionality and/or Moose attributes to perform any construction work
796 necessary for your class.
798 =head2 __PACKAGE__->mk_accessor('meta');
800 Won't work due to a limitation of L<Moose>. This is currently being fixed
803 =head2 Class::Data::Inheritable side effects
805 Previously, writing to a class data accessor would copy the accessor method
806 down into your package.
808 This behavior has been removed. While the class data is still stored
809 per-class, it is stored on the metaclass of the class defining the accessor.
811 Therefore anything relying on the side effect of the accessor being copied down
814 The following test demonstrates the problem:
818 use base qw/Class::Data::Inheritable/;
819 __PACKAGE__->mk_classdata('foo');
824 use base qw/BaseClass/;
827 BaseClass->foo('base class');
828 Child->foo('sub class');
831 isnt(BaseClass->can('foo'), Child->can('foo'));
833 =head2 Extending Catalyst::Request or other classes in an ad hoc manner using mk_accessors
835 Previously, it was possible to add additional accessors to Catalyst::Request
836 (or other classes) by calling the mk_accessors class method.
838 This is no longer supported - users should make a subclass of the class whose
839 behavior they would like to change, rather than globally polluting the
842 =head2 Confused multiple inheritance with Catalyst::Component::COMPONENT
844 Previously, Catalyst's COMPONENT method would delegate to the method on
845 the right hand side, which could then delegate back again with
846 NEXT. This is poor practice, and in addition, makes no sense with C3
847 method dispatch order, and is therefore no longer supported.
849 If a COMPONENT method is detected in the inheritance hierarchy to the right
850 hand side of Catalyst::Component::COMPONENT, then the following warning
851 message will be emitted:
853 There is a COMPONENT method resolving after Catalyst::Component
856 The correct fix is to re-arrange your class's inheritance hierarchy so that the
857 COMPONENT method you would like to inherit is the first (left-hand most)
858 COMPONENT method in your @ISA.
860 =head2 Development server relying on environment variables
862 Previously, the development server would allow propagation of system
863 environment variables into the request environment, this has changed with the
864 adoption of Plack. You can use L<Plack::Middleware::ForceEnv> to achieve the
869 =head2 Actions in your application class
871 Having actions in your application class will now emit a warning at application
872 startup as this is deprecated. It is highly recommended that these actions are moved
873 into a MyApp::Controller::Root (as demonstrated by the scaffold application
874 generated by catalyst.pl).
876 This warning, also affects tests. You should move actions in your test,
877 creating a myTest::Controller::Root, like the following example:
879 package MyTest::Controller::Root;
884 use parent 'Catalyst::Controller';
886 __PACKAGE__->config(namespace => '');
889 my ( $self, $c ) = @_;
895 =head2 ::[MVC]:: naming scheme
897 Having packages called MyApp::[MVC]::XX is deprecated and can no longer be generated
900 This is still supported, but it is recommended that you rename your application
901 components to Model/View/Controller.
903 A warning will be issued at application startup if the ::[MVC]:: naming scheme is
906 =head2 Catalyst::Base
908 Any code using L<Catalyst::Base> will now emit a warning; this
909 module will be removed in a future release.
911 =head2 Methods in Catalyst::Dispatcher
913 The following methods in Catalyst::Dispatcher are implementation
914 details, which may change in the 5.8X release series, and therefore their use
915 is highly deprecated.
923 =item registered_dispatch_types
925 =item method_action_class
933 The first time one of these methods is called, a warning will be emitted:
935 Class $class is calling the deprecated method Catalyst::Dispatcher::$public_method_name,
936 this will be removed in Catalyst 5.9
938 You should B<NEVER> be calling any of these methods from application code.
940 Plugin authors and maintainers whose plugins currently call these methods
941 should change to using the public API, or, if you do not feel the public API
942 adequately supports your use case, please email the development list to
943 discuss what API features you need so that you can be appropriately supported.
945 =head2 Class files with names that don't correspond to the packages they define
947 In this version of Catalyst, if a component is loaded from disk, but no
948 symbols are defined in that component's name space after it is loaded, this
949 warning will be issued:
951 require $class was successful but the package is not defined.
953 This is to protect against confusing bugs caused by mistyping package names,
954 and will become a fatal error in a future version.
956 Please note that 'inner packages' (via L<Devel::InnerPackage>) are still fully
957 supported; this warning is only issued when component file naming does not map
958 to B<any> of the packages defined within that component.
960 =head2 $c->plugin method
962 Calling the plugin method is deprecated, and calling it at run time is B<highly
965 Instead you are recommended to use L<Catalyst::Model::Adaptor> or similar to
966 compose the functionality you need outside of the main application name space.
968 Calling the plugin method will not be supported past Catalyst 5.81.