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 =head1 Upgrading to Catalyst 5.90095
44 The method C<last_error> in L</Catalyst> was actually returning the first error. This has
45 been fixed but there is a small chance it could be a breaking issue for you. If this gives
46 you trouble changing to C<shift_errors> is the easiest workaround (although that does
47 modify the error stack so if you are relying on that not being changed you should try something
48 like @{$c->errors}[-1] instead. Since this method is relatively new and the cases when the
49 error stack actually has more than one error in it, we feel the exposure is very low, but bug
50 reports are very welcomed.
52 =head1 Upgrading to Catalyst 5.90090
54 L<Catalyst::Utils> has a new method 'inject_component' which works the same as the method of
55 the same name in L<CatalystX::InjectComponent>. You should start converting any
56 use of the non core method in your code as future changes to Catalyst will be
57 sychronized to the core method first. We reserve the right to cease support
58 of the non core version should we reach a point in time where it cannot be
59 properly supported as an external module. Luckily this should be a trivial
60 search and replace. Change all occurances of:
62 CatalystX::InjectComponent->inject(...)
66 Catalyst::Utils::inject_component(...)
68 and we expect everything to work the same (we'd consider it not working the same
69 to be a bug, and please report it.)
71 We also cored features from L<CatalystX::RoleApplicator> to compose a role into the
72 request, response and stats classes. The main difference is that with L<CatalystX::RoleApplicator>
78 use CatalystX::RoleApplicator;
80 __PACKAGE__->apply_request_class_roles(
81 qw/My::Request::Role Other::Request::Role/);
83 Whereas now we have three class attributes, 'request_class_traits', 'response_class_traits'
84 and 'stats_class_traits', so you use like this (note this value is an ArrayRef)
91 __PACKAGE__->request_class_traits([qw/
93 Other::Request::Role/]);
95 (And the same for response_class_traits and stats_class_traits. We left off the
96 traits for Engine, since that class does a lot less nowadays, and dispatcher. If you
97 used those and can share a use case, we'd be likely to support them.
99 Lastly, we have some of the feature from L<CatalystX::ComponentsFromConfig> in
100 core. This should mostly work the same way in core, except for now the
101 core version does not create an automatic base wrapper class for your configured
102 components (it requires these to be catalyst components and injects them directly.
103 So if you make heavy use of custom base classes in L<CatalystX::ComponentsFromConfig>
104 you might need a bit of work to use the core version (although there is no reason
105 to stop using L<CatalystX::ComponentsFromConfig> since it should continue to work
106 fine and we'd consider issues with it to be bugs). Here's one way to map from
107 L<CatalystX::ComponentsFromConfig> to core:
109 In L<CatalystX::ComponentsFromConfig>:
112 'Model::MyClass' => {
121 inject_components => {
122 'Model::MyClass' => { from_component => 'My::Class' },
124 'Model::MyClass' => {
129 Although the cored behavior requires more code, its better separates concerns
130 as well as plays more into core Catalyst expections of how configuration shoul
133 Also we added a new develop console mode only warning when you call a component
134 with arguments that don't expect or do anything meaningful with those args. Its
135 possible if you are logging debug mode in production (please don't...) this
136 could add verbosity to those logs if you also happen to be calling for components
137 and passing pointless arguments. We added this warning to help people not make this
138 error and to better understand the component resolution flow.
140 =head1 Upgrading to Catalyst 5.90085
142 In this version of Catalyst we made a small change to Chained Dispatching so
143 that when two or more actions all have the same path specification AND they
144 all have Args(0), we break the tie by choosing the last action defined, and
145 not the first one defined. This was done to normalize Chaining to following
146 the 'longest Path wins, and when several actions match the same Path specification
147 we choose the last defined.' rule. Previously Args(0) was hard coded to be a special
148 case such that the first action defined would match (which is not the case when
151 Its possible that this could be a breaking change for you, if you had used
152 action roles (custom or otherwise) to add additional matching rules to differentiate
153 between several Args(0) actions that share the same root action chain. For
154 example if you have code now like this:
156 sub check_default :Chained(/) CaptureArgs(0) { ... }
158 sub default_get :Chained('check_default') PathPart('') Args(0) GET {
159 pop->res->body('get3');
162 sub default_post :Chained('check_default') PathPart('') Args(0) POST {
163 pop->res->body('post3');
166 sub chain_default :Chained('check_default') PathPart('') Args(0) {
167 pop->res->body('chain_default');
170 The way that chaining will work previous is that when two or more equal actions can
171 match, the 'top' one wins. So if the request is "GET .../check_default" BOTH
172 actions 'default_get' AND 'chain_default' would match. To break the tie in
173 the case when Args is 0, we'd previous take the 'top' (or first defined) action.
174 Unfortunately this treatment of Args(0) is special case. In all other cases
175 we choose the 'last defined' action to break a tie. So this version of
176 Catalyst changed the dispatcher to make Args(0) no longer a special case for
177 breaking ties. This means that the above code must now become:
179 sub check_default :Chained(/) CaptureArgs(0) { ... }
181 sub chain_default :Chained('check_default') PathPart('') Args(0) {
182 pop->res->body('chain_default');
185 sub default_get :Chained('check_default') PathPart('') Args(0) GET {
186 pop->res->body('get3');
189 sub default_post :Chained('check_default') PathPart('') Args(0) POST {
190 pop->res->body('post3');
193 If we want it to work as expected (for example we we GET to match 'default_get' and
194 POST to match 'default_post' and any other http Method to match 'chain_default').
196 In other words Arg(0) and chained actions must now follow the normal rule where
197 in a tie the last defined action wins and you should place all your less defined
198 or 'catch all' actions first.
200 If this causes you trouble and you can't fix your code to conform, you may set the
201 application configuration setting "use_chained_args_0_special_case" to true and
202 that will revert you code to the previous behavior.
204 =head2 More backwards compatibility options with UTF-8 changes
206 In order to give better backwards compatiblity with the 5.90080+ UTF-8 changes
207 we've added several configuration options around control of how we try to decode
208 your URL keywords / query parameters.
210 C<do_not_decode_query>
212 If true, then do not try to character decode any wide characters in your
213 request URL query or keywords. Most readings of the relevent specifications
214 suggest these should be UTF-* encoded, which is the default that L<Catalyst>
215 will use, hwoever if you are creating a lot of URLs manually or have external
216 evil clients, this might cause you trouble. If you find the changes introduced
217 in Catalyst version 5.90080+ break some of your query code, you may disable
218 the UTF-8 decoding globally using this configuration.
220 This setting takes precedence over C<default_query_encoding> and
221 C<decode_query_using_global_encoding>
223 C<default_query_encoding>
225 By default we decode query and keywords in your request URL using UTF-8, which
226 is our reading of the relevent specifications. This setting allows one to
227 specify a fixed value for how to decode your query. You might need this if
228 you are doing a lot of custom encoding of your URLs and not using UTF-8.
230 This setting take precedence over C<decode_query_using_global_encoding>.
232 C<decode_query_using_global_encoding>
234 Setting this to true will default your query decoding to whatever your
235 general global encoding is (the default is UTF-8).
238 =head1 Upgrading to Catalyst 5.90080
240 UTF8 encoding is now default. For temporary backwards compatibility, if this
241 change is causing you trouble, you can disable it by setting the application
242 configuration option to undef:
244 MyApp->config(encoding => undef);
246 But please consider this a temporary measure since it is the intention that
247 UTF8 is enabled going forwards and the expectation is that other ecosystem
248 projects will assume this as well. At some point you application will not
249 correctly function without this setting.
251 As of 5.90084 we've added two additional configuration flags for more selective
252 control over some encoding changes: 'skip_body_param_unicode_decoding' and
253 'skip_complex_post_part_handling'. You may use these to more selectively
254 disable new features while you are seeking a long term fix. Please review
255 CONFIGURATION in L<Catalyst>.
257 For further information, please see L<Catalyst::UTF8>
259 A number of projects in the wider ecosystem required minor updates to be able
260 to work correctly. Here's the known list:
262 L<Catalyst::View::TT>, L<Catalyst::View::Mason>, L<Catalyst::View::HTML::Mason>,
263 L<Catalyst::View::Xslate>, L<Test::WWW::Mechanize::Catalyst>
265 You will need to update to modern versions in most cases, although quite a few
266 of these only needed minor test case and documentation changes so you will need
267 to review the changelog of each one that is relevant to you to determine your
270 =head1 Upgrading to Catalyst 5.90060
272 Starting in the v5.90059_001 development release, the regexp dispatch type is
273 no longer automatically included as a dependency. If you are still using this
274 dispatch type, you need to add L<Catalyst::DispatchType::Regex> into your build
277 The standalone distribution of Regexp will be supported for the time being, but
278 should we find that supporting it prevents us from moving L<Catalyst> forward
279 in necessary ways, we reserve the right to drop that support. It is highly
280 recommended that you use this last stage of deprecation to change your code.
282 =head1 Upgrading to Catalyst 5.90040
284 =head2 Catalyst::Plugin::Unicode::Encoding is now core
286 The previously stand alone Unicode support module L<Catalyst::Plugin::Unicode::Encoding>
287 has been brought into core as a default plugin. Going forward, all you need is
288 to add a configuration setting for the encoding type. For example:
294 __PACKAGE__->config( encoding => 'UTF-8' );
296 Please note that this is different from the old stand alone plugin which applied
297 C<UTF-8> encoding by default (that is, if you did not set an explicit
298 C<encoding> configuration value, it assumed you wanted UTF-8). In order to
299 preserve backwards compatibility you will need to explicitly turn it on via the
300 configuration setting. THIS MIGHT CHANGE IN THE FUTURE, so please consider
301 starting to test your application with proper UTF-8 support and remove all those
302 crappy hacks you munged into the code because you didn't know the Plugin
305 For people that are using the Plugin, you will note a startup warning suggesting
306 that you can remove it from the plugin list. When you do so, please remember to
307 add the configuration setting, since you can no longer rely on the default being
308 UTF-8. We'll add it for you if you continue to use the stand alone plugin and
309 we detect this, but this backwards compatibility shim will likely be removed in
310 a few releases (trying to clean up the codebase after all).
312 If you have trouble with any of this, please bring it to the attention of the
313 Catalyst maintainer group.
315 =head2 basic async and event loop support
317 This version of L<Catalyst> offers some support for using L<AnyEvent> and
318 L<IO::Async> event loops in your application. These changes should work
319 fine for most applications however if you are already trying to perform
320 some streaming, minor changes in this area of the code might affect your
321 functionality. Please see L<Catalyst::Response\write_fh> for more and for a
324 We consider this feature experimental. We will try not to break it, but we
325 reserve the right to make necessary changes to fix major issues that people
326 run into when the use this functionality in the wild.
328 =head1 Upgrading to Catalyst 5.90030
330 =head2 Regex dispatch type is deprecated.
332 The Regex dispatchtype (L<Catalyst::DispatchType::Regex>) has been deprecated.
334 You are encouraged to move your application to Chained dispatch (L<Catalyst::DispatchType::Chained>).
336 If you cannot do so, please add a dependency to Catalyst::DispatchType::Regex to your application's
339 =head1 Upgrading to Catalyst 5.9
341 The major change is that L<Plack>, a toolkit for using the L<PSGI>
342 specification, now replaces most of the subclasses of L<Catalyst::Engine>. If
343 you are using one of the standard subclasses of L<Catalyst::Engine> this
344 should be a straightforward upgrade for you. It was a design goal for
345 this release to preserve as much backwards compatibility as possible.
346 However, since L<Plack> is different from L<Catalyst::Engine>, it is
347 possible that differences exist for edge cases. Therefore, we recommend
348 that care be taken with this upgrade and that testing should be greater
349 than would be the case with a minor point update. Please inform the
350 Catalyst developers of any problems so that we can fix them and
353 It is highly recommended that you become familiar with the L<Plack> ecosystem
354 and documentation. Being able to take advantage of L<Plack> development and
355 middleware is a major bonus to this upgrade. Documentation about how to
356 take advantage of L<Plack::Middleware> by writing your own C<< .psgi >> file
357 is contained in L<Catalyst::PSGI>.
359 If you have created a custom subclass of L<Catalyst:Engine>, you will
360 need to convert it to be a subclass of L<Plack::Handler>.
362 If you are using the L<Plack> engine, L<Catalyst::Engine::PSGI>, this new
363 release supersedes that code.
365 If you are using a subclass of L<Catalyst::Engine> that is aimed at
366 nonstandard or internal/testing uses, such as
367 L<Catalyst::Engine::Embeddable>, you should still be able to continue
370 Advice for specific subclasses of L<Catalyst::Engine> follows:
372 =head2 Upgrading the FastCGI Engine
374 No upgrade is needed if your myapp_fastcgi.pl script is already upgraded
375 to use L<Catalyst::Script::FastCGI>.
377 =head2 Upgrading the mod_perl / Apache Engines
379 The engines that are built upon the various iterations of mod_perl,
380 L<Catalyst::Engine::Apache::MP13> (for mod_perl 1, and Apache 1.x) and
381 L<Catalyst::Engine::Apache2::MP20> (for mod_perl 2, and Apache 2.x),
382 should be seamless upgrades and will work using L<Plack::Handler::Apache1>
383 or L<Plack::Handler::Apache2> as required.
385 L<Catalyst::Engine::Apache2::MP19>, however, is no longer supported, as
386 Plack does not support mod_perl version 1.99. This is unlikely to be a
387 problem for anyone, as 1.99 was a brief beta-test release for mod_perl
388 2, and all users of mod_perl 1.99 are encouraged to upgrade to a
389 supported release of Apache 2 and mod_perl 2.
391 =head2 Upgrading the HTTP Engine
393 The default development server that comes with the L<Catalyst> distribution
394 should continue to work as expected with no changes as long as your C<myapp_server>
395 script is upgraded to use L<Catalyst::Script::HTTP>.
397 =head2 Upgrading the CGI Engine
399 If you were using L<Catalyst::Engine::CGI> there is no upgrade needed if your
400 myapp_cgi.pl script is already upgraded to use L<Catalyst::Script::CGI>.
402 =head2 Upgrading Catalyst::Engine::HTTP::Prefork
404 If you were using L<Catalyst::Engine::HTTP::Prefork> then L<Starman>
405 is automatically loaded. You should (at least) change your C<Makefile.PL>
406 to depend on Starman.
408 You can regenerate your C<myapp_server.pl> script with C<catalyst.pl>
409 and implement a C<MyApp::Script::Server> class that looks like this:
411 package MyApp::Script::Server;
413 use namespace::autoclean;
415 extends 'CatalystX::Script::Server::Starman';
419 This takes advantage of the new script system, and will add a number of
420 options to the standard server script as extra options are added by
423 More information about these options can be seen at
424 L<CatalystX::Script::Server::Starman/SYNOPSIS>.
426 An alternate route to implement this functionality is to write a simple .psgi
427 file for your application, and then use the L<plackup> utility to start the
430 =head2 Upgrading the PSGI Engine
432 If you were using L<Catalyst::Engine::PSGI>, this new release supersedes
433 this engine in supporting L<Plack>. By default the Engine is now always
434 L<Plack>. As a result, you can remove the dependency on
435 L<Catalyst::Engine::PSGI> in your C<Makefile.PL>.
437 Applications that were using L<Catalyst::Engine::PSGI>
438 previously should entirely continue to work in this release with no changes.
440 However, if you have an C<app.psgi> script, then you no longer need to
441 specify the PSGI engine. Instead, the L<Catalyst> application class now
442 has a new method C<psgi_app> which returns a L<PSGI> compatible coderef
443 which you can wrap in the middleware of your choice.
445 Catalyst will use the .psgi for your application if it is located in the C<home>
446 directory of the application.
448 For example, if you were using L<Catalyst::Engine::PSGI> in the past, you will
449 have written (or generated) a C<script/myapp.psgi> file similar to this one:
454 MyCatalystApp->setup_engine('PSGI');
457 enable ... # enable your desired middleware
458 sub { MyCatalystApp->run(@_) };
461 Instead, you now say:
467 enable ... #enable your desired middleware
468 MyCatalystApp->psgi_app;
471 In the simplest case:
473 MyCatalystApp->setup_engine('PSGI');
474 my $app = sub { MyCatalystApp->run(@_) }
478 my $app = MyCatalystApp->psgi_app(@_);
482 my $app = sub { MyCatalystApp->psgi_app(@_) };
483 # If you make ^^ this mistake, your app won't work, and will confuse the hell out of you!
485 You can now move C<< script/myapp.psgi >> to C<< myapp.psgi >>, and the built-in
486 Catalyst scripts and your test suite will start using your .psgi file.
488 B<NOTE:> If you rename your .psgi file without these modifications, then
489 any tests run via L<Catalyst::Test> will not be compatible with the new
490 release, and will result in the development server starting, rather than
491 the expected test running.
493 B<NOTE:> If you are directly accessing C<< $c->req->env >> to get the PSGI
494 environment then this accessor is moved to C<< $c->engine->env >>,
495 you will need to update your code.
497 =head2 Engines which are known to be broken
499 The following engines B<DO NOT> work as of Catalyst version 5.9. The
500 core team will be happy to work with the developers and/or users of
501 these engines to help them port to the new Plack/Engine system, but for
502 now, applications which are currently using these engines B<WILL NOT>
503 run without modification to the engine code.
507 =item Catalyst::Engine::Wx
509 =item Catalyst::Engine::Zeus
511 =item Catalyst::Engine::JobQueue::POE
513 =item Catalyst::Engine::XMPP2
515 =item Catalyst::Engine::SCGI
519 =head2 Engines with unknown status
521 The following engines are untested or have unknown compatibility.
522 Reports are highly encouraged:
526 =item Catalyst::Engine::Mojo
528 =item Catalyst::Engine::Server (marked as Deprecated)
530 =item Catalyst::Engine::HTTP::POE (marked as Deprecated)
534 =head2 Plack functionality
536 See L<Catalyst::PSGI>.
540 Tests should generally work the same in Catalyst 5.9, but there are
543 Previously, if using L<Catalyst::Test> and doing local requests (against
544 a local server), if the application threw an exception then this
545 exception propagated into the test.
547 This behavior has been removed, and now a 500 response will be returned
548 to the test. This change standardizes behavior, so that local test
549 requests behave similarly to remote requests.
551 =head1 Upgrading to Catalyst 5.80
553 Most applications and plugins should run unaltered on Catalyst 5.80.
555 However, a lot of refactoring work has taken place, and several changes have
556 been made which could cause incompatibilities. If your application or plugin
557 is using deprecated code, or relying on side effects, then you could have
558 issues upgrading to this release.
560 Most issues found with existing components have been easy to
561 solve. This document provides a complete description of behavior changes
562 which may cause compatibility issues, and of new Catalyst warnings which
565 If you think you have found an upgrade-related issue which is not covered in
566 this document, please email the Catalyst list to discuss the problem.
568 =head1 Moose features
570 =head2 Application class roles
572 You can only apply method modifiers after the application's C<< ->setup >>
573 method has been called. This means that modifiers will not work with methods
574 run during the call to C<< ->setup >>.
576 See L<Catalyst::Manual::ExtendingCatalyst> for more information about using
577 L<Moose> in your applications.
579 =head2 Controller actions in Moose roles
581 You can use L<MooseX::MethodAttributes::Role> if you want to declare actions
584 =head2 Using Moose in Components
586 The correct way to use Moose in a component in a both forward and backwards
589 package TestApp::Controller::Root;
591 BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
593 See L<Components which inherit from Moose::Object before Catalyst::Component>.
595 =head1 Known backwards compatibility breakages
597 =head2 Applications in a single file
599 Applications must be in their own file, and loaded at compile time. This
600 issue generally only affects the tests of CPAN distributions. Your
601 application will fail if you try to define an application inline in a
602 block, and use plugins which supply a C< new > method, then use that
603 application latter in tests within the same file.
605 This is due to the fact that Catalyst is inlining a new method on your
606 application class allowing it to be compatible with Moose. The method
607 used to do this changed in 5.80004 to avoid the possibility of reporting
608 an 'Unknown Error' if your application failed to compile.
610 =head2 Issues with Class::C3
612 Catalyst 5.80 uses the L<Algorithm::C3> method dispatch order. This is
613 built into Perl 5.10, and comes via L<Class::C3> for Perl 5.8. This
614 replaces L<NEXT> with L<Class::C3::Adopt::NEXT>, forcing all components
615 to resolve methods using C3, rather than the unpredictable dispatch
618 This issue manifests itself by your application failing to start due to an
619 error message about having a non-linear @ISA.
621 The Catalyst plugin most often causing this is
622 L<Catalyst::Plugin::Session::Store::FastMmap> - if you are using this
623 plugin and see issues, then please upgrade your plugins, as it has been
624 fixed. Note that Makefile.PL in the distribution will warn about known
625 incompatible components.
627 This issue can, however, be found in your own application - the only solution is
628 to go through each base class of the class the error was reported against, until
629 you identify the ones in conflict, and resolve them.
631 To be able to generate a linear @ISA, the list of superclasses for each
632 class must be resolvable using the C3 algorithm. Unfortunately, when
633 superclasses are being used as mixins (to add functionality used in your class),
634 and with multiple inheritance, it is easy to get this wrong.
636 Most common is the case of:
638 package Component1; # Note, this is the common case
639 use base qw/Class::Accessor::Fast Class::Data::Inheritable/;
641 package Component2; # Accidentally saying it this way causes a failure
642 use base qw/Class::Data::Inheritable Class::Accessor::Fast/;
645 use base qw/Component1 Component2/;
647 Any situation like this will cause your application to fail to start.
649 For additional documentation about this issue, and how to resolve it, see
650 L<Class::C3::Adopt::NEXT>.
652 =head2 Components which inherit from Moose::Object before Catalyst::Component
654 Moose components which say:
656 package TestApp::Controller::Example;
658 extends qw/Moose::Object Catalyst::Component/;
660 to use the constructor provided by Moose, while working (if you do some hacks
661 with the C< BUILDARGS > method), will not work with Catalyst 5.80 as
662 C<Catalyst::Component> inherits from C<Moose::Object>, and so C< @ISA > fails
665 The correct way to use Moose in a component in a both forward and backwards
668 package TestApp::Controller::Root;
670 BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
672 Note that the C< extends > declaration needs to occur in a begin block for
673 L<attributes> to operate correctly.
675 This way you do not inherit directly from C<Moose::Object>
676 yourself. Having components which do not inherit their constructor from
677 C<Catalyst::Component> is B<unsupported>, and has never been recommended,
678 therefore you're on your own if you're using this technique. You'll need
679 to detect the version of Catalyst your application is running, and deal
680 with it appropriately.
682 You also don't get the L<Moose::Object> constructor, and therefore attribute
683 initialization will not work as normally expected. If you want to use Moose
684 attributes, then they need to be made lazy to correctly initialize.
686 Note that this only applies if your component needs to maintain component
687 backwards compatibility for Catalyst versions before 5.71001 - in 5.71001
688 attributes work as expected, and the BUILD method is called normally
689 (although BUILDARGS is not).
691 If you depend on Catalyst 5.8, then B<all> Moose features work as expected.
693 You will also see this issue if you do the following:
695 package TestApp::Controller::Example;
697 use base 'Catalyst::Controller';
699 as C< use base > appends to @ISA.
701 =head3 use Moose in MyApp
703 Similar to the above, this will also fail:
712 If you need to use Moose in your application class (e.g. for method modifiers
713 etc.) then the correct technique is:
721 __PACKAGE__->config( name => 'MyApp' );
722 __PACKAGE__->setup(qw/
726 =head2 Anonymous closures installed directly into the symbol table
728 If you have any code which installs anonymous subroutine references directly
729 into the symbol table, you may encounter breakages. The simplest solution is
730 to use L<Sub::Name> to name the subroutine. Example:
732 # Original code, likely to break:
733 my $full_method_name = join('::', $package_name, $method_name);
734 *$full_method_name = sub { ... };
737 use Sub::Name 'subname';
738 my $full_method_name = join('::',$package_name, $method_name);
739 *$full_method_name = subname $full_method_name, sub { ... };
741 Additionally, you can take advantage of Catalyst's use of L<Class::MOP> and
742 install the closure using the appropriate metaclass. Example:
745 my $metaclass = Moose::Meta::Class->initialize($package_name);
746 $metaclass->add_method($method_name => sub { ... });
748 =head2 Hooking into application setup
750 To execute code during application start-up, the following snippet in MyApp.pm
754 my ($class, @args) = @_;
755 $class->NEXT::setup(@args);
756 ... # things to do after the actual setup
759 With Catalyst 5.80 this won't work anymore, because Catalyst no longer
760 uses NEXT.pm for method resolution. The functionality was only ever
761 originally operational as L<NEXT> remembers what methods have already
762 been called, and will not call them again.
764 Using this now causes infinite recursion between MyApp::setup and
765 Catalyst::setup, due to other backwards compatibility issues related to how
766 plugin setup works. Moose method modifiers like C<< before|after|around setup
767 => sub { ... }; >> also will not operate correctly on the setup method.
769 The right way to do it is this:
771 after setup_finalize => sub {
772 ... # things to do after the actual setup
775 The setup_finalize hook was introduced as a way to avoid this issue.
777 =head2 Components with a new method which returns false
779 Previously, if you had a component which inherited from Catalyst::COMPONENT,
780 but overrode the new method to return false, then your class's configuration
781 would be blessed into a hash on your behalf, and this would be returned from
782 the COMPONENT method.
784 This behavior makes no sense, and so has been removed. Implementing your own
785 C< new > method in components is B<highly> discouraged. Instead, you should
786 inherit the new method from Catalyst::Component, and use Moose's BUILD
787 functionality and/or Moose attributes to perform any construction work
788 necessary for your class.
790 =head2 __PACKAGE__->mk_accessor('meta');
792 Won't work due to a limitation of L<Moose>. This is currently being fixed
795 =head2 Class::Data::Inheritable side effects
797 Previously, writing to a class data accessor would copy the accessor method
798 down into your package.
800 This behavior has been removed. While the class data is still stored
801 per-class, it is stored on the metaclass of the class defining the accessor.
803 Therefore anything relying on the side effect of the accessor being copied down
806 The following test demonstrates the problem:
810 use base qw/Class::Data::Inheritable/;
811 __PACKAGE__->mk_classdata('foo');
816 use base qw/BaseClass/;
819 BaseClass->foo('base class');
820 Child->foo('sub class');
823 isnt(BaseClass->can('foo'), Child->can('foo'));
825 =head2 Extending Catalyst::Request or other classes in an ad hoc manner using mk_accessors
827 Previously, it was possible to add additional accessors to Catalyst::Request
828 (or other classes) by calling the mk_accessors class method.
830 This is no longer supported - users should make a subclass of the class whose
831 behavior they would like to change, rather than globally polluting the
834 =head2 Confused multiple inheritance with Catalyst::Component::COMPONENT
836 Previously, Catalyst's COMPONENT method would delegate to the method on
837 the right hand side, which could then delegate back again with
838 NEXT. This is poor practice, and in addition, makes no sense with C3
839 method dispatch order, and is therefore no longer supported.
841 If a COMPONENT method is detected in the inheritance hierarchy to the right
842 hand side of Catalyst::Component::COMPONENT, then the following warning
843 message will be emitted:
845 There is a COMPONENT method resolving after Catalyst::Component
848 The correct fix is to re-arrange your class's inheritance hierarchy so that the
849 COMPONENT method you would like to inherit is the first (left-hand most)
850 COMPONENT method in your @ISA.
852 =head2 Development server relying on environment variables
854 Previously, the development server would allow propagation of system
855 environment variables into the request environment, this has changed with the
856 adoption of Plack. You can use L<Plack::Middleware::ForceEnv> to achieve the
861 =head2 Actions in your application class
863 Having actions in your application class will now emit a warning at application
864 startup as this is deprecated. It is highly recommended that these actions are moved
865 into a MyApp::Controller::Root (as demonstrated by the scaffold application
866 generated by catalyst.pl).
868 This warning, also affects tests. You should move actions in your test,
869 creating a myTest::Controller::Root, like the following example:
871 package MyTest::Controller::Root;
876 use parent 'Catalyst::Controller';
878 __PACKAGE__->config(namespace => '');
881 my ( $self, $c ) = @_;
887 =head2 ::[MVC]:: naming scheme
889 Having packages called MyApp::[MVC]::XX is deprecated and can no longer be generated
892 This is still supported, but it is recommended that you rename your application
893 components to Model/View/Controller.
895 A warning will be issued at application startup if the ::[MVC]:: naming scheme is
898 =head2 Catalyst::Base
900 Any code using L<Catalyst::Base> will now emit a warning; this
901 module will be removed in a future release.
903 =head2 Methods in Catalyst::Dispatcher
905 The following methods in Catalyst::Dispatcher are implementation
906 details, which may change in the 5.8X release series, and therefore their use
907 is highly deprecated.
915 =item registered_dispatch_types
917 =item method_action_class
925 The first time one of these methods is called, a warning will be emitted:
927 Class $class is calling the deprecated method Catalyst::Dispatcher::$public_method_name,
928 this will be removed in Catalyst 5.9
930 You should B<NEVER> be calling any of these methods from application code.
932 Plugin authors and maintainers whose plugins currently call these methods
933 should change to using the public API, or, if you do not feel the public API
934 adequately supports your use case, please email the development list to
935 discuss what API features you need so that you can be appropriately supported.
937 =head2 Class files with names that don't correspond to the packages they define
939 In this version of Catalyst, if a component is loaded from disk, but no
940 symbols are defined in that component's name space after it is loaded, this
941 warning will be issued:
943 require $class was successful but the package is not defined.
945 This is to protect against confusing bugs caused by mistyping package names,
946 and will become a fatal error in a future version.
948 Please note that 'inner packages' (via L<Devel::InnerPackage>) are still fully
949 supported; this warning is only issued when component file naming does not map
950 to B<any> of the packages defined within that component.
952 =head2 $c->plugin method
954 Calling the plugin method is deprecated, and calling it at run time is B<highly
957 Instead you are recommended to use L<Catalyst::Model::Adaptor> or similar to
958 compose the functionality you need outside of the main application name space.
960 Calling the plugin method will not be supported past Catalyst 5.81.