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 Components whos new method returns false
82 Previously if your new method returned a false value,
84 Previously, if you had a component which inherited from Catalyst::COMPONENT, but
85 overrode the new method, to return false, then your class' configuration would be blessed into a hash on your behalf,
86 and this would be returned from the COMPONENT method. T
88 This behaviour makes no sense, and so has been removed.. You are recommended to implement your own new method
89 in components, instead, you should inherit the new method from Catalyst::Component, and use Moose's BUILD functionality
90 to perform any construction work necessary for your sub-class.
92 =head2 __PACKAGE__->mk_accessor('meta');
94 Won't work due to a limitation of L<Moose>
96 This is currently being fixed inside core Moose.
98 =head2 Class::Data::Inheritable side effects
100 Previously, writing to a class data accessor would copy the accessor method down into your package.
102 This behavior has been removed. Whilst the class data is still stored per-class, it is stored on
103 the metaclass of the class defining the accessor.
105 Therefore anything relying on the side-effect of the accessor being copied down will be broken.
107 =head2 Extending Catalyst::Request or other classes in an ad-hoc manor using mk_accessors
109 Previously, it was possible to add additional accessors to Catalyst::Request (or other classes)
110 by calling the mk_accessors class method.
112 This is no longer supported - users should make a sub-class of the class who's behavior they would
113 like to change, rather than globally polluting the Catalyst objects.
115 =head2 Confused multiple inheritance with Catalyst::Component::COMPONENT
119 There is a COMPONENT method resolving after Catalyst::Component
122 This means that one of the packages on the right hand side of
123 Catalyst::Component in your Class' inheritance hierarchy defines
126 Previously, Catalyst's COMPONENT method would delegate to the
127 method on the right hand side, which could then delegate back again
128 with NEXT. This (as it is insane), is no longer supported, as it
129 makes no sense with C3 method dispatch order.
131 Therefore the correct fix is to re-arrange your class' inheritance
132 hierarchy so that the COMPONENT method you would like to inherit is
133 the first COMPONENT method in your @ISA.
135 =head2 Assigning lists to accessors
137 Accessors generated by Class::Accessor::Fast will, when multiple values
138 are assigned to them, store a reference to a list automatically for you.
140 This is not currently supported by MooseX::Emulate::Class::Accessor::Fast,
141 and only the first value in the list will be stored.
143 If you are relying on this behavior, and inheriting mk_accessors from a
144 Catalyst component, then your code will fail.
148 =head2 Methods in Catalyst::Dispatcher
150 The following methods in Catalyst::Dispatcher are likely to change
151 significantly in the 5.8X release series, and therefore their use is highly
160 =item registered_dispatch_types
162 =item method_action_class
170 The first time one of these methods is called, a warning will be emitted:
172 Class $class is calling the deprecated method Catalyst::Dispatcher::$public_method_name,\n"
173 . "this will be removed in Catalyst 5.9X"
175 You should B<NEVER> be calling any of these methods from application code.
177 Plugins authors and maintainers whos plugins need to call these methods
178 should email the development list to discuss your use-case, and what a
179 better API should look like.
181 =head2 require $class was successful but the package is not defined.
183 In this version of Catalyst, if a component is loaded from disk, but no symbols are defined in that component's namespace
184 after it is loaded, this warning will be issued.
186 This is to protect against confusing bugs caused by mis-typing package names.
188 This will become a fatal error in a future version.
190 =head2 $c->plugin method
192 Calling the plugin method is deprecated, and calling it at runtime is B<highly deprecated>.
194 Instead you are recommended to use L< Catalyst::Model::Adaptor > or similar to compose the functionality
195 you need outside of the main application namespace.