1 =head1 Upgrading to Catalyst 5.80
3 Most applications and plugins should run unaltered on Catalyst 5.80.
5 However as a lot of refactoring work has taken place, several changes
6 have been made which could cause incompatibilities, if your application
7 or plugin is using deprecated code, or relying on side-effects then
8 there could be incompatibility.
10 Most issues found with pre-existing components have been easy to solve,
11 and a complete description of behavior changes which may cause compatibility
12 issues, or warnings to be emitted is included below to help if you have
15 If you think you have found an upgrade related issue which is not covered in
16 this document, then please email the Catalyst list to discuss the problem.
18 =head1 Known backwards compatibility breakages.
20 =head2 Components which inherit from Moose::Object before Catalyst::Component
22 Moose components which say:
24 package TestApp::Controller::Example;
26 extends qw/Moose::Object Catalyst::Component/;
28 to use the constructor provided by Moose, whilst working if you do some hacks
29 with the C< BUILDARGS > method, will not work with Catalyst 5.80 as
30 C<Catalyst::Component> inherits from C<Moose::Object>, and so C< @ISA > fails
33 The fix for this, is to not inherit directly from C<Moose::Object>
34 yourself. Having components which do not inherit their constructor from
35 C<Catalyst::Component> is B<unsupported>, and has never been recommended,
36 therefore you're on your own if you're using this technique. You'll need
37 to detect the version of Catalyst your application is running with and deal
38 with it appropriately.
40 You will also see this issue if you do the following:
42 package TestApp::Controller::Example;
44 use base 'Catalyst::Controller';
46 as C< use base > appends to @ISA.
48 The correct way to use Moose in a component in a both forward and backwards
51 package TestApp::Controller::Root;
53 BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
55 Note that the C< extends > decleration needs to occur in a begin block for
56 L<attributes> to operate correctly.
58 =head2 Anonymous closures installed directly into the symbol table
60 If you have any code which installs anonymous subroutine references directly
61 into the symbol table, you may encounter breakages. The simplest solution is
62 to use L<Sub::Name> to name the subroutine. Example:
64 #Originalcode, likely to break:
65 my $full_method_name = join('::',$package_name, $method_name);
66 *$full_method_name = sub { ... };
69 use Sub::Name 'subname';
70 my $full_method_name = join('::',$package_name, $method_name);
71 *$full_method_name = subname $full_method_name, sub { ... };
73 Additionally, you can take advantage of Catalyst's use of L<Class::MOP> and
74 install the closure using the appropriate metaclass. Example:
77 my $metaclass = Moose::Meta::Class->initialize($package_name);
78 $metaclass->add_method($method_name => sub { ... });
80 =head2 Hooking into application setup
82 To execute code during application startup the following snippet in MyApp.pm
86 my ($class, @args) = @_;
87 $class->NEXT::setup(@args);
88 ... # things to do after the actual setup
91 With Catalyst 5.80 this won't work anymore. Because instead of using NEXT.pm it
92 relies on Class::C3::Adopt::NEXT, which doesn't remember what methods it
93 already called, like NEXT does and therefore goes into a deep recursion between
94 MyApp::setup and Catalyst::setup.
96 Moose method modifiers line C<< before|after|around 'setup => sub { ... }; >>
97 won't work either because of backward compatibility issues related to plugin
100 The right way to do it is this:
102 after setup_finalize => sub {
103 ... # things to do after the actual setup
106 =head2 Components whos new method returns false
108 Previously, if you had a component which inherited from Catalyst::COMPONENT,
109 but overrode the new method, to return false, then your class' configuration
110 would be blessed into a hash on your behalf, and this would be returned from
111 the COMPONENT method.
113 This behaviour makes no sense, and so has been removed.. You are recommended to
114 implement your own new method in components, instead, you should inherit the
115 new method from Catalyst::Component, and use Moose's BUILD functionality to
116 perform any construction work necessary for your sub-class.
118 =head2 __PACKAGE__->mk_accessor('meta');
120 Won't work due to a limitation of L<Moose>
122 This is currently being fixed inside core Moose.
124 =head2 Class::Data::Inheritable side effects
126 Previously, writing to a class data accessor would copy the accessor method
127 down into your package.
129 This behavior has been removed. Whilst the class data is still stored
130 per-class, it is stored on the metaclass of the class defining the accessor.
132 Therefore anything relying on the side-effect of the accessor being copied down
135 The following example demonstrates the problem:
139 use base qw/Class::Data::Inheritable/;
140 __PACKAGE__->mk_classdata('foo');
145 use base qw/BaseClass/;
148 BaseClass->foo('base class');
149 Child->foo('sub class');
151 isnt(BaseClass->can('foo'), Child->can('foo'));
153 =head2 Extending Catalyst::Request or other classes in an ad-hoc manor using mk_accessors
155 Previously, it was possible to add additional accessors to Catalyst::Request
156 (or other classes) by calling the mk_accessors class method.
158 This is no longer supported - users should make a sub-class of the class who's
159 behavior they would like to change, rather than globally polluting the Catalyst
162 =head2 Confused multiple inheritance with Catalyst::Component::COMPONENT
166 There is a COMPONENT method resolving after Catalyst::Component
169 This means that one of the packages on the right hand side of
170 Catalyst::Component in your Class' inheritance hierarchy defines
173 Previously, Catalyst's COMPONENT method would delegate to the
174 method on the right hand side, which could then delegate back again
175 with NEXT. This (as it is insane), is no longer supported, as it
176 makes no sense with C3 method dispatch order.
178 Therefore the correct fix is to re-arrange your class' inheritance
179 hierarchy so that the COMPONENT method you would like to inherit is
180 the first COMPONENT method in your @ISA.
184 =head2 Methods in Catalyst::Dispatcher
186 The following methods in Catalyst::Dispatcher are likely to change
187 significantly in the 5.8X release series, and therefore their use is highly
196 =item registered_dispatch_types
198 =item method_action_class
206 The first time one of these methods is called, a warning will be emitted:
208 Class $class is calling the deprecated method Catalyst::Dispatcher::$public_method_name,\n"
209 . "this will be removed in Catalyst 5.9X"
211 You should B<NEVER> be calling any of these methods from application code.
213 Plugins authors and maintainers whos plugins need to call these methods should
214 email the development list to discuss your use-case, and what a better API
217 =head2 require $class was successful but the package is not defined.
219 In this version of Catalyst, if a component is loaded from disk, but no symbols
220 are defined in that component's namespace after it is loaded, this warning will
223 This is to protect against confusing bugs caused by mis-typing package names.
225 This will become a fatal error in a future version.
227 =head2 $c->plugin method
229 Calling the plugin method is deprecated, and calling it at runtime is B<highly
232 Instead you are recommended to use L< Catalyst::Model::Adaptor > or similar to
233 compose the functionality you need outside of the main application namespace.