3 Catalyst::Upgrading - Instructions for upgrading to the latest Catalyst
5 =head1 Upgrading to Catalyst 5.90121
7 A new C<log_stats> method has been added. This will only affect
8 subclasses that have a method with this name added.
10 =head1 Upgrading to Catalyst 5.90100
12 We changed the way the middleware stash works so that it no longer localizes
13 the PSGI env hashref. This was done to fix bugs where people set PSGI ENV hash
14 keys and found them to disappear in certain cases. It also means that now if
15 a sub applications sets stash variables, that stash will now bubble up to the
16 parent application. This may be a breaking change for you since previous
17 versions of this code did not allow that. A workaround is to explicitly delete
18 stash keys in your sub application before returning control to the parent
21 =head1 Upgrading to Catalyst 5.90097
23 In older versions of Catalyst one could construct a L<URI> with a fragment (such as
24 https://localhost/foo/bar#fragment) by using a '#' in the path or final argument, for
27 $c->uri_for($action, 'foo#fragment');
29 This behavior was never documented and would break if using the Unicode plugin, or when
30 adding a query to the arguments:
32 $c->uri_for($action, 'foo#fragment', +{ a=>1, b=>2});
34 would define a fragment like "#fragment?a=1&b=2".
36 When we introduced UTF-8 encoding by default in Catalyst 5.9008x this side effect behavior
37 was broken since we started encoding the '#' when it was part of the URI path.
39 In version 5.90095 and 5.90096 we attempted to fix this, but all we managed to do was break
40 people with URIs that included '#' as part of the path data, when it was not expected to
41 be a fragment delimiter.
43 In general L<Catalyst> prefers an explicit specification rather than relying on side effects
44 or domain specific mini languages. As a result we are now defining how to set a fragment
45 for a URI via ->uri_for:
47 $c->uri_for($action_or_path, \@captures_or_args, @args, \$query, \$fragment);
49 If you are relying on the previous side effect behavior your URLs will now encode the '#'
50 delimiter, which is going to be a breaking change for you. You need to alter your code
51 to match the new specification or modify uri_for for your local case. Patches to solve
52 this are very welcomed, as long as they don't break existing test cases.
54 B<NOTE> If you are using the string form of the first argument:
56 $c->uri_for('/foo/bar#baz')
58 construction, we do not attempt to encode this and it will make a URL with a
62 =head1 Upgrading to Catalyst 5.90095
64 The method C<last_error> in L</Catalyst> was actually returning the first error. This has
65 been fixed but there is a small chance it could be a breaking issue for you. If this gives
66 you trouble changing to C<shift_errors> is the easiest workaround (although that does
67 modify the error stack so if you are relying on that not being changed you should try something
68 like @{$c->errors}[-1] instead. Since this method is relatively new and the cases when the
69 error stack actually has more than one error in it, we feel the exposure is very low, but bug
70 reports are very welcomed.
72 =head1 Upgrading to Catalyst 5.90090
74 L<Catalyst::Utils> has a new method 'inject_component' which works the same as the method of
75 the same name in L<CatalystX::InjectComponent>. You should start converting any
76 use of the non core method in your code as future changes to Catalyst will be
77 synchronized to the core method first. We reserve the right to cease support
78 of the non core version should we reach a point in time where it cannot be
79 properly supported as an external module. Luckily this should be a trivial
80 search and replace. Change all occurrences of:
82 CatalystX::InjectComponent->inject(...)
86 Catalyst::Utils::inject_component(...)
88 and we expect everything to work the same (we'd consider it not working the same
89 to be a bug, and please report it.)
91 We also cored features from L<CatalystX::RoleApplicator> to compose a role into the
92 request, response and stats classes. The main difference is that with L<CatalystX::RoleApplicator>
98 use CatalystX::RoleApplicator;
100 __PACKAGE__->apply_request_class_roles(
101 qw/My::Request::Role Other::Request::Role/);
103 Whereas now we have three class attributes, 'request_class_traits', 'response_class_traits'
104 and 'stats_class_traits', so you use like this (note this value is an ArrayRef)
111 __PACKAGE__->request_class_traits([qw/
113 Other::Request::Role/]);
115 (And the same for response_class_traits and stats_class_traits. We left off the
116 traits for Engine, since that class does a lot less nowadays, and dispatcher. If you
117 used those and can share a use case, we'd be likely to support them.
119 Lastly, we have some of the feature from L<CatalystX::ComponentsFromConfig> in
120 core. This should mostly work the same way in core, except for now the
121 core version does not create an automatic base wrapper class for your configured
122 components (it requires these to be catalyst components and injects them directly.
123 So if you make heavy use of custom base classes in L<CatalystX::ComponentsFromConfig>
124 you might need a bit of work to use the core version (although there is no reason
125 to stop using L<CatalystX::ComponentsFromConfig> since it should continue to work
126 fine and we'd consider issues with it to be bugs). Here's one way to map from
127 L<CatalystX::ComponentsFromConfig> to core:
129 In L<CatalystX::ComponentsFromConfig>:
132 'Model::MyClass' => {
141 inject_components => {
142 'Model::MyClass' => { from_component => 'My::Class' },
144 'Model::MyClass' => {
149 Although the core behavior requires more code, it better separates concerns
150 as well as plays more into core Catalyst expectations of how configuration should
153 Also we added a new develop console mode only warning when you call a component
154 with arguments that don't expect or do anything meaningful with those args. Its
155 possible if you are logging debug mode in production (please don't...) this
156 could add verbosity to those logs if you also happen to be calling for components
157 and passing pointless arguments. We added this warning to help people not make this
158 error and to better understand the component resolution flow.
160 =head1 Upgrading to Catalyst 5.90085
162 In this version of Catalyst we made a small change to Chained Dispatching so
163 that when two or more actions all have the same path specification AND they
164 all have Args(0), we break the tie by choosing the last action defined, and
165 not the first one defined. This was done to normalize Chaining to following
166 the 'longest Path wins, and when several actions match the same Path specification
167 we choose the last defined.' rule. Previously Args(0) was hard coded to be a special
168 case such that the first action defined would match (which is not the case when
171 Its possible that this could be a breaking change for you, if you had used
172 action roles (custom or otherwise) to add additional matching rules to differentiate
173 between several Args(0) actions that share the same root action chain. For
174 example if you have code now like this:
176 sub check_default :Chained(/) CaptureArgs(0) { ... }
178 sub default_get :Chained('check_default') PathPart('') Args(0) GET {
179 pop->res->body('get3');
182 sub default_post :Chained('check_default') PathPart('') Args(0) POST {
183 pop->res->body('post3');
186 sub chain_default :Chained('check_default') PathPart('') Args(0) {
187 pop->res->body('chain_default');
190 The way that chaining will work previous is that when two or more equal actions can
191 match, the 'top' one wins. So if the request is "GET .../check_default" BOTH
192 actions 'default_get' AND 'chain_default' would match. To break the tie in
193 the case when Args is 0, we'd previous take the 'top' (or first defined) action.
194 Unfortunately this treatment of Args(0) is special case. In all other cases
195 we choose the 'last defined' action to break a tie. So this version of
196 Catalyst changed the dispatcher to make Args(0) no longer a special case for
197 breaking ties. This means that the above code must now become:
199 sub check_default :Chained(/) CaptureArgs(0) { ... }
201 sub chain_default :Chained('check_default') PathPart('') Args(0) {
202 pop->res->body('chain_default');
205 sub default_get :Chained('check_default') PathPart('') Args(0) GET {
206 pop->res->body('get3');
209 sub default_post :Chained('check_default') PathPart('') Args(0) POST {
210 pop->res->body('post3');
213 If we want it to work as expected (for example we we GET to match 'default_get' and
214 POST to match 'default_post' and any other http Method to match 'chain_default').
216 In other words Arg(0) and chained actions must now follow the normal rule where
217 in a tie the last defined action wins and you should place all your less defined
218 or 'catch all' actions first.
220 If this causes you trouble and you can't fix your code to conform, you may set the
221 application configuration setting "use_chained_args_0_special_case" to true and
222 that will revert you code to the previous behavior.
224 =head2 More backwards compatibility options with UTF-8 changes
226 In order to give better backwards compatibility with the 5.90080+ UTF-8 changes
227 we've added several configuration options around control of how we try to decode
228 your URL keywords / query parameters.
230 C<do_not_decode_query>
232 If true, then do not try to character decode any wide characters in your
233 request URL query or keywords. Most readings of the relevant specifications
234 suggest these should be UTF-* encoded, which is the default that L<Catalyst>
235 will use, however if you are creating a lot of URLs manually or have external
236 evil clients, this might cause you trouble. If you find the changes introduced
237 in Catalyst version 5.90080+ break some of your query code, you may disable
238 the UTF-8 decoding globally using this configuration.
240 This setting takes precedence over C<default_query_encoding> and
241 C<decode_query_using_global_encoding>
243 C<default_query_encoding>
245 By default we decode query and keywords in your request URL using UTF-8, which
246 is our reading of the relevant specifications. This setting allows one to
247 specify a fixed value for how to decode your query. You might need this if
248 you are doing a lot of custom encoding of your URLs and not using UTF-8.
250 This setting take precedence over C<decode_query_using_global_encoding>.
252 C<decode_query_using_global_encoding>
254 Setting this to true will default your query decoding to whatever your
255 general global encoding is (the default is UTF-8).
258 =head1 Upgrading to Catalyst 5.90080
260 UTF8 encoding is now default. For temporary backwards compatibility, if this
261 change is causing you trouble, you can disable it by setting the application
262 configuration option to undef:
264 MyApp->config(encoding => undef);
266 But please consider this a temporary measure since it is the intention that
267 UTF8 is enabled going forwards and the expectation is that other ecosystem
268 projects will assume this as well. At some point you application will not
269 correctly function without this setting.
271 As of 5.90084 we've added two additional configuration flags for more selective
272 control over some encoding changes: 'skip_body_param_unicode_decoding' and
273 'skip_complex_post_part_handling'. You may use these to more selectively
274 disable new features while you are seeking a long term fix. Please review
275 CONFIGURATION in L<Catalyst>.
277 For further information, please see L<Catalyst::UTF8>
279 A number of projects in the wider ecosystem required minor updates to be able
280 to work correctly. Here's the known list:
282 L<Catalyst::View::TT>, L<Catalyst::View::Mason>, L<Catalyst::View::HTML::Mason>,
283 L<Catalyst::View::Xslate>, L<Test::WWW::Mechanize::Catalyst>
285 You will need to update to modern versions in most cases, although quite a few
286 of these only needed minor test case and documentation changes so you will need
287 to review the changelog of each one that is relevant to you to determine your
290 =head1 Upgrading to Catalyst 5.90060
292 Starting in the v5.90059_001 development release, the regexp dispatch type is
293 no longer automatically included as a dependency. If you are still using this
294 dispatch type, you need to add L<Catalyst::DispatchType::Regex> into your build
297 The standalone distribution of Regexp will be supported for the time being, but
298 should we find that supporting it prevents us from moving L<Catalyst> forward
299 in necessary ways, we reserve the right to drop that support. It is highly
300 recommended that you use this last stage of deprecation to change your code.
302 =head1 Upgrading to Catalyst 5.90040
304 =head2 Catalyst::Plugin::Unicode::Encoding is now core
306 The previously stand alone Unicode support module L<Catalyst::Plugin::Unicode::Encoding>
307 has been brought into core as a default plugin. Going forward, all you need is
308 to add a configuration setting for the encoding type. For example:
314 __PACKAGE__->config( encoding => 'UTF-8' );
316 Please note that this is different from the old stand alone plugin which applied
317 C<UTF-8> encoding by default (that is, if you did not set an explicit
318 C<encoding> configuration value, it assumed you wanted UTF-8). In order to
319 preserve backwards compatibility you will need to explicitly turn it on via the
320 configuration setting. THIS MIGHT CHANGE IN THE FUTURE, so please consider
321 starting to test your application with proper UTF-8 support and remove all those
322 crappy hacks you munged into the code because you didn't know the Plugin
325 For people that are using the Plugin, you will note a startup warning suggesting
326 that you can remove it from the plugin list. When you do so, please remember to
327 add the configuration setting, since you can no longer rely on the default being
328 UTF-8. We'll add it for you if you continue to use the stand alone plugin and
329 we detect this, but this backwards compatibility shim will likely be removed in
330 a few releases (trying to clean up the codebase after all).
332 If you have trouble with any of this, please bring it to the attention of the
333 Catalyst maintainer group.
335 =head2 basic async and event loop support
337 This version of L<Catalyst> offers some support for using L<AnyEvent> and
338 L<IO::Async> event loops in your application. These changes should work
339 fine for most applications however if you are already trying to perform
340 some streaming, minor changes in this area of the code might affect your
341 functionality. Please see L<Catalyst::Response\write_fh> for more and for a
344 We consider this feature experimental. We will try not to break it, but we
345 reserve the right to make necessary changes to fix major issues that people
346 run into when the use this functionality in the wild.
348 =head1 Upgrading to Catalyst 5.90030
350 =head2 Regex dispatch type is deprecated.
352 The Regex dispatchtype (L<Catalyst::DispatchType::Regex>) has been deprecated.
354 You are encouraged to move your application to Chained dispatch (L<Catalyst::DispatchType::Chained>).
356 If you cannot do so, please add a dependency to Catalyst::DispatchType::Regex to your application's
359 =head1 Upgrading to Catalyst 5.9
361 The major change is that L<Plack>, a toolkit for using the L<PSGI>
362 specification, now replaces most of the subclasses of L<Catalyst::Engine>. If
363 you are using one of the standard subclasses of L<Catalyst::Engine> this
364 should be a straightforward upgrade for you. It was a design goal for
365 this release to preserve as much backwards compatibility as possible.
366 However, since L<Plack> is different from L<Catalyst::Engine>, it is
367 possible that differences exist for edge cases. Therefore, we recommend
368 that care be taken with this upgrade and that testing should be greater
369 than would be the case with a minor point update. Please inform the
370 Catalyst developers of any problems so that we can fix them and
373 It is highly recommended that you become familiar with the L<Plack> ecosystem
374 and documentation. Being able to take advantage of L<Plack> development and
375 middleware is a major bonus to this upgrade. Documentation about how to
376 take advantage of L<Plack::Middleware> by writing your own C<< .psgi >> file
377 is contained in L<Catalyst::PSGI>.
379 If you have created a custom subclass of L<Catalyst:Engine>, you will
380 need to convert it to be a subclass of L<Plack::Handler>.
382 If you are using the L<Plack> engine, L<Catalyst::Engine::PSGI>, this new
383 release supersedes that code.
385 If you are using a subclass of L<Catalyst::Engine> that is aimed at
386 nonstandard or internal/testing uses, such as
387 L<Catalyst::Engine::Embeddable>, you should still be able to continue
390 Advice for specific subclasses of L<Catalyst::Engine> follows:
392 =head2 Upgrading the FastCGI Engine
394 No upgrade is needed if your myapp_fastcgi.pl script is already upgraded
395 to use L<Catalyst::Script::FastCGI>.
397 =head2 Upgrading the mod_perl / Apache Engines
399 The engines that are built upon the various iterations of mod_perl,
400 L<Catalyst::Engine::Apache::MP13> (for mod_perl 1, and Apache 1.x) and
401 L<Catalyst::Engine::Apache2::MP20> (for mod_perl 2, and Apache 2.x),
402 should be seamless upgrades and will work using L<Plack::Handler::Apache1>
403 or L<Plack::Handler::Apache2> as required.
405 L<Catalyst::Engine::Apache2::MP19>, however, is no longer supported, as
406 Plack does not support mod_perl version 1.99. This is unlikely to be a
407 problem for anyone, as 1.99 was a brief beta-test release for mod_perl
408 2, and all users of mod_perl 1.99 are encouraged to upgrade to a
409 supported release of Apache 2 and mod_perl 2.
411 =head2 Upgrading the HTTP Engine
413 The default development server that comes with the L<Catalyst> distribution
414 should continue to work as expected with no changes as long as your C<myapp_server>
415 script is upgraded to use L<Catalyst::Script::HTTP>.
417 =head2 Upgrading the CGI Engine
419 If you were using L<Catalyst::Engine::CGI> there is no upgrade needed if your
420 myapp_cgi.pl script is already upgraded to use L<Catalyst::Script::CGI>.
422 =head2 Upgrading Catalyst::Engine::HTTP::Prefork
424 If you were using L<Catalyst::Engine::HTTP::Prefork> then L<Starman>
425 is automatically loaded. You should (at least) change your C<Makefile.PL>
426 to depend on Starman.
428 You can regenerate your C<myapp_server.pl> script with C<catalyst.pl>
429 and implement a C<MyApp::Script::Server> class that looks like this:
431 package MyApp::Script::Server;
433 use namespace::autoclean;
435 extends 'CatalystX::Script::Server::Starman';
439 This takes advantage of the new script system, and will add a number of
440 options to the standard server script as extra options are added by
443 More information about these options can be seen at
444 L<CatalystX::Script::Server::Starman/SYNOPSIS>.
446 An alternate route to implement this functionality is to write a simple .psgi
447 file for your application, and then use the L<plackup> utility to start the
450 =head2 Upgrading the PSGI Engine
452 If you were using L<Catalyst::Engine::PSGI>, this new release supersedes
453 this engine in supporting L<Plack>. By default the Engine is now always
454 L<Plack>. As a result, you can remove the dependency on
455 L<Catalyst::Engine::PSGI> in your C<Makefile.PL>.
457 Applications that were using L<Catalyst::Engine::PSGI>
458 previously should entirely continue to work in this release with no changes.
460 However, if you have an C<app.psgi> script, then you no longer need to
461 specify the PSGI engine. Instead, the L<Catalyst> application class now
462 has a new method C<psgi_app> which returns a L<PSGI> compatible coderef
463 which you can wrap in the middleware of your choice.
465 Catalyst will use the .psgi for your application if it is located in the C<home>
466 directory of the application.
468 For example, if you were using L<Catalyst::Engine::PSGI> in the past, you will
469 have written (or generated) a C<script/myapp.psgi> file similar to this one:
474 MyCatalystApp->setup_engine('PSGI');
477 enable ... # enable your desired middleware
478 sub { MyCatalystApp->run(@_) };
481 Instead, you now say:
487 enable ... #enable your desired middleware
488 MyCatalystApp->psgi_app;
491 In the simplest case:
493 MyCatalystApp->setup_engine('PSGI');
494 my $app = sub { MyCatalystApp->run(@_) }
498 my $app = MyCatalystApp->psgi_app(@_);
502 my $app = sub { MyCatalystApp->psgi_app(@_) };
503 # If you make ^^ this mistake, your app won't work, and will confuse the hell out of you!
505 You can now move C<< script/myapp.psgi >> to C<< myapp.psgi >>, and the built-in
506 Catalyst scripts and your test suite will start using your .psgi file.
508 B<NOTE:> If you rename your .psgi file without these modifications, then
509 any tests run via L<Catalyst::Test> will not be compatible with the new
510 release, and will result in the development server starting, rather than
511 the expected test running.
513 B<NOTE:> If you are directly accessing C<< $c->req->env >> to get the PSGI
514 environment then this accessor is moved to C<< $c->engine->env >>,
515 you will need to update your code.
517 =head2 Engines which are known to be broken
519 The following engines B<DO NOT> work as of Catalyst version 5.9. The
520 core team will be happy to work with the developers and/or users of
521 these engines to help them port to the new Plack/Engine system, but for
522 now, applications which are currently using these engines B<WILL NOT>
523 run without modification to the engine code.
527 =item Catalyst::Engine::Wx
529 =item Catalyst::Engine::Zeus
531 =item Catalyst::Engine::JobQueue::POE
533 =item Catalyst::Engine::XMPP2
535 =item Catalyst::Engine::SCGI
539 =head2 Engines with unknown status
541 The following engines are untested or have unknown compatibility.
542 Reports are highly encouraged:
546 =item Catalyst::Engine::Mojo
548 =item Catalyst::Engine::Server (marked as Deprecated)
550 =item Catalyst::Engine::HTTP::POE (marked as Deprecated)
554 =head2 Plack functionality
556 See L<Catalyst::PSGI>.
560 Tests should generally work the same in Catalyst 5.9, but there are
563 Previously, if using L<Catalyst::Test> and doing local requests (against
564 a local server), if the application threw an exception then this
565 exception propagated into the test.
567 This behavior has been removed, and now a 500 response will be returned
568 to the test. This change standardizes behavior, so that local test
569 requests behave similarly to remote requests.
571 =head1 Upgrading to Catalyst 5.80
573 Most applications and plugins should run unaltered on Catalyst 5.80.
575 However, a lot of refactoring work has taken place, and several changes have
576 been made which could cause incompatibilities. If your application or plugin
577 is using deprecated code, or relying on side effects, then you could have
578 issues upgrading to this release.
580 Most issues found with existing components have been easy to
581 solve. This document provides a complete description of behavior changes
582 which may cause compatibility issues, and of new Catalyst warnings which
585 If you think you have found an upgrade-related issue which is not covered in
586 this document, please email the Catalyst list to discuss the problem.
588 =head1 Moose features
590 =head2 Application class roles
592 You can only apply method modifiers after the application's C<< ->setup >>
593 method has been called. This means that modifiers will not work with methods
594 run during the call to C<< ->setup >>.
596 See L<Catalyst::Manual::ExtendingCatalyst> for more information about using
597 L<Moose> in your applications.
599 =head2 Controller actions in Moose roles
601 You can use L<MooseX::MethodAttributes::Role> if you want to declare actions
604 =head2 Using Moose in Components
606 The correct way to use Moose in a component in a both forward and backwards
609 package TestApp::Controller::Root;
611 BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
613 See L<Components which inherit from Moose::Object before Catalyst::Component>.
615 =head1 Known backwards compatibility breakages
617 =head2 Applications in a single file
619 Applications must be in their own file, and loaded at compile time. This
620 issue generally only affects the tests of CPAN distributions. Your
621 application will fail if you try to define an application inline in a
622 block, and use plugins which supply a C< new > method, then use that
623 application latter in tests within the same file.
625 This is due to the fact that Catalyst is inlining a new method on your
626 application class allowing it to be compatible with Moose. The method
627 used to do this changed in 5.80004 to avoid the possibility of reporting
628 an 'Unknown Error' if your application failed to compile.
630 =head2 Issues with Class::C3
632 Catalyst 5.80 uses the L<Algorithm::C3> method dispatch order. This is
633 built into Perl 5.10, and comes via L<Class::C3> for Perl 5.8. This
634 replaces L<NEXT> with L<Class::C3::Adopt::NEXT>, forcing all components
635 to resolve methods using C3, rather than the unpredictable dispatch
638 This issue manifests itself by your application failing to start due to an
639 error message about having a non-linear @ISA.
641 The Catalyst plugin most often causing this is
642 L<Catalyst::Plugin::Session::Store::FastMmap> - if you are using this
643 plugin and see issues, then please upgrade your plugins, as it has been
644 fixed. Note that Makefile.PL in the distribution will warn about known
645 incompatible components.
647 This issue can, however, be found in your own application - the only solution is
648 to go through each base class of the class the error was reported against, until
649 you identify the ones in conflict, and resolve them.
651 To be able to generate a linear @ISA, the list of superclasses for each
652 class must be resolvable using the C3 algorithm. Unfortunately, when
653 superclasses are being used as mixins (to add functionality used in your class),
654 and with multiple inheritance, it is easy to get this wrong.
656 Most common is the case of:
658 package Component1; # Note, this is the common case
659 use base qw/Class::Accessor::Fast Class::Data::Inheritable/;
661 package Component2; # Accidentally saying it this way causes a failure
662 use base qw/Class::Data::Inheritable Class::Accessor::Fast/;
665 use base qw/Component1 Component2/;
667 Any situation like this will cause your application to fail to start.
669 For additional documentation about this issue, and how to resolve it, see
670 L<Class::C3::Adopt::NEXT>.
672 =head2 Components which inherit from Moose::Object before Catalyst::Component
674 Moose components which say:
676 package TestApp::Controller::Example;
678 extends qw/Moose::Object Catalyst::Component/;
680 to use the constructor provided by Moose, while working (if you do some hacks
681 with the C< BUILDARGS > method), will not work with Catalyst 5.80 as
682 C<Catalyst::Component> inherits from C<Moose::Object>, and so C< @ISA > fails
685 The correct way to use Moose in a component in a both forward and backwards
688 package TestApp::Controller::Root;
690 BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
692 Note that the C< extends > declaration needs to occur in a begin block for
693 L<attributes> to operate correctly.
695 This way you do not inherit directly from C<Moose::Object>
696 yourself. Having components which do not inherit their constructor from
697 C<Catalyst::Component> is B<unsupported>, and has never been recommended,
698 therefore you're on your own if you're using this technique. You'll need
699 to detect the version of Catalyst your application is running, and deal
700 with it appropriately.
702 You also don't get the L<Moose::Object> constructor, and therefore attribute
703 initialization will not work as normally expected. If you want to use Moose
704 attributes, then they need to be made lazy to correctly initialize.
706 Note that this only applies if your component needs to maintain component
707 backwards compatibility for Catalyst versions before 5.71001 - in 5.71001
708 attributes work as expected, and the BUILD method is called normally
709 (although BUILDARGS is not).
711 If you depend on Catalyst 5.8, then B<all> Moose features work as expected.
713 You will also see this issue if you do the following:
715 package TestApp::Controller::Example;
717 use base 'Catalyst::Controller';
719 as C< use base > appends to @ISA.
721 =head3 use Moose in MyApp
723 Similar to the above, this will also fail:
732 If you need to use Moose in your application class (e.g. for method modifiers
733 etc.) then the correct technique is:
741 __PACKAGE__->config( name => 'MyApp' );
742 __PACKAGE__->setup(qw/
746 =head2 Anonymous closures installed directly into the symbol table
748 If you have any code which installs anonymous subroutine references directly
749 into the symbol table, you may encounter breakages. The simplest solution is
750 to use L<Sub::Name> to name the subroutine. Example:
752 # Original code, likely to break:
753 my $full_method_name = join('::', $package_name, $method_name);
754 *$full_method_name = sub { ... };
757 use Sub::Name 'subname';
758 my $full_method_name = join('::',$package_name, $method_name);
759 *$full_method_name = subname $full_method_name, sub { ... };
761 Additionally, you can take advantage of Catalyst's use of L<Class::MOP> and
762 install the closure using the appropriate metaclass. Example:
765 my $metaclass = Moose::Meta::Class->initialize($package_name);
766 $metaclass->add_method($method_name => sub { ... });
768 =head2 Hooking into application setup
770 To execute code during application start-up, the following snippet in MyApp.pm
774 my ($class, @args) = @_;
775 $class->NEXT::setup(@args);
776 ... # things to do after the actual setup
779 With Catalyst 5.80 this won't work anymore, because Catalyst no longer
780 uses NEXT.pm for method resolution. The functionality was only ever
781 originally operational as L<NEXT> remembers what methods have already
782 been called, and will not call them again.
784 Using this now causes infinite recursion between MyApp::setup and
785 Catalyst::setup, due to other backwards compatibility issues related to how
786 plugin setup works. Moose method modifiers like C<< before|after|around setup
787 => sub { ... }; >> also will not operate correctly on the setup method.
789 The right way to do it is this:
791 after setup_finalize => sub {
792 ... # things to do after the actual setup
795 The setup_finalize hook was introduced as a way to avoid this issue.
797 =head2 Components with a new method which returns false
799 Previously, if you had a component which inherited from Catalyst::COMPONENT,
800 but overrode the new method to return false, then your class's configuration
801 would be blessed into a hash on your behalf, and this would be returned from
802 the COMPONENT method.
804 This behavior makes no sense, and so has been removed. Implementing your own
805 C< new > method in components is B<highly> discouraged. Instead, you should
806 inherit the new method from Catalyst::Component, and use Moose's BUILD
807 functionality and/or Moose attributes to perform any construction work
808 necessary for your class.
810 =head2 __PACKAGE__->mk_accessor('meta');
812 Won't work due to a limitation of L<Moose>. This is currently being fixed
815 =head2 Class::Data::Inheritable side effects
817 Previously, writing to a class data accessor would copy the accessor method
818 down into your package.
820 This behavior has been removed. While the class data is still stored
821 per-class, it is stored on the metaclass of the class defining the accessor.
823 Therefore anything relying on the side effect of the accessor being copied down
826 The following test demonstrates the problem:
830 use base qw/Class::Data::Inheritable/;
831 __PACKAGE__->mk_classdata('foo');
836 use base qw/BaseClass/;
839 BaseClass->foo('base class');
840 Child->foo('sub class');
843 isnt(BaseClass->can('foo'), Child->can('foo'));
845 =head2 Extending Catalyst::Request or other classes in an ad hoc manner using mk_accessors
847 Previously, it was possible to add additional accessors to Catalyst::Request
848 (or other classes) by calling the mk_accessors class method.
850 This is no longer supported - users should make a subclass of the class whose
851 behavior they would like to change, rather than globally polluting the
854 =head2 Confused multiple inheritance with Catalyst::Component::COMPONENT
856 Previously, Catalyst's COMPONENT method would delegate to the method on
857 the right hand side, which could then delegate back again with
858 NEXT. This is poor practice, and in addition, makes no sense with C3
859 method dispatch order, and is therefore no longer supported.
861 If a COMPONENT method is detected in the inheritance hierarchy to the right
862 hand side of Catalyst::Component::COMPONENT, then the following warning
863 message will be emitted:
865 There is a COMPONENT method resolving after Catalyst::Component
868 The correct fix is to re-arrange your class's inheritance hierarchy so that the
869 COMPONENT method you would like to inherit is the first (left-hand most)
870 COMPONENT method in your @ISA.
872 =head2 Development server relying on environment variables
874 Previously, the development server would allow propagation of system
875 environment variables into the request environment, this has changed with the
876 adoption of Plack. You can use L<Plack::Middleware::ForceEnv> to achieve the
881 =head2 Actions in your application class
883 Having actions in your application class will now emit a warning at application
884 startup as this is deprecated. It is highly recommended that these actions are moved
885 into a MyApp::Controller::Root (as demonstrated by the scaffold application
886 generated by catalyst.pl).
888 This warning, also affects tests. You should move actions in your test,
889 creating a myTest::Controller::Root, like the following example:
891 package MyTest::Controller::Root;
896 use parent 'Catalyst::Controller';
898 __PACKAGE__->config(namespace => '');
901 my ( $self, $c ) = @_;
907 =head2 ::[MVC]:: naming scheme
909 Having packages called MyApp::[MVC]::XX is deprecated and can no longer be generated
912 This is still supported, but it is recommended that you rename your application
913 components to Model/View/Controller.
915 A warning will be issued at application startup if the ::[MVC]:: naming scheme is
918 =head2 Catalyst::Base
920 Any code using L<Catalyst::Base> will now emit a warning; this
921 module will be removed in a future release.
923 =head2 Methods in Catalyst::Dispatcher
925 The following methods in Catalyst::Dispatcher are implementation
926 details, which may change in the 5.8X release series, and therefore their use
927 is highly deprecated.
935 =item registered_dispatch_types
937 =item method_action_class
945 The first time one of these methods is called, a warning will be emitted:
947 Class $class is calling the deprecated method Catalyst::Dispatcher::$public_method_name,
948 this will be removed in Catalyst 5.9
950 You should B<NEVER> be calling any of these methods from application code.
952 Plugin authors and maintainers whose plugins currently call these methods
953 should change to using the public API, or, if you do not feel the public API
954 adequately supports your use case, please email the development list to
955 discuss what API features you need so that you can be appropriately supported.
957 =head2 Class files with names that don't correspond to the packages they define
959 In this version of Catalyst, if a component is loaded from disk, but no
960 symbols are defined in that component's name space after it is loaded, this
961 warning will be issued:
963 require $class was successful but the package is not defined.
965 This is to protect against confusing bugs caused by mistyping package names,
966 and will become a fatal error in a future version.
968 Please note that 'inner packages' (via L<Devel::InnerPackage>) are still fully
969 supported; this warning is only issued when component file naming does not map
970 to B<any> of the packages defined within that component.
972 =head2 $c->plugin method
974 Calling the plugin method is deprecated, and calling it at run time is B<highly
977 Instead you are recommended to use L<Catalyst::Model::Adaptor> or similar to
978 compose the functionality you need outside of the main application name space.
980 Calling the plugin method will not be supported past Catalyst 5.81.