List assignment to MX::Emulate::CAF accessors now works.

[catagits/Catalyst-Runtime.git] / lib / Catalyst / Upgrading.pod

diff --git a/lib/Catalyst/Upgrading.pod b/lib/Catalyst/Upgrading.pod
index 92cc25e..b370334 100644 (file)
--- a/lib/Catalyst/Upgrading.pod
+++ b/lib/Catalyst/Upgrading.pod
@@ -7,7 +7,7 @@ have been made which could cause incompatibilities, if your application
 or plugin is using deprecated code, or relying on side-effects then
 there could be incompatibility.
 
-Most issues found with pre-existing components have been easy to solve, 
+Most issues found with pre-existing components have been easy to solve,
 and a complete description of behavior changes which may cause compatibility
 issues, or warnings to be emitted is included below to help if you have
 problems.
@@ -17,16 +17,43 @@ this document, then please email the Catalyst list to discuss the problem.
 
 =head1 Known backwards compatibility breakages.
 
-=head2 Moose applications
+=head2 Components which inherit from Moose::Object before Catalyst::Component
 
-Moose components for Catalyst 5.70 needed to do
+Moose components which say:
 
+    package TestApp::Controller::Example;
+    use Moose;
     extends qw/Moose::Object Catalyst::Component/;
 
-to be able to use the constructor provided by Moose. In 5.80
-C<Catalyst::Component> already inherits from C<Moose::Object>. Therefor you
-shouldn't directly inherit from C<Moose::Object> yourself, otherwise your
-Class' @ISA will not linearize with C3.
+to use the constructor provided by Moose, whilst working if you do some hacks
+with the C< BUILDARGS > method, will not work with Catalyst 5.80 as
+C<Catalyst::Component> inherits from C<Moose::Object>, and so C< @ISA > fails
+to linearise.
+
+The fix for this, is to not inherit directly from C<Moose::Object>
+yourself. Having components which do not inherit their constructor from
+C<Catalyst::Component> is B<unsupported>, and has never been recommended,
+therefore you're on your own if you're using this technique. You'll need
+to detect the version of Catalyst your application is running with and deal
+with it appropriately.
+
+You will also see this issue if you do the following:
+
+    package TestApp::Controller::Example;
+    use Moose;
+    use base 'Catalyst::Controller';
+
+as C< use base > appends to @ISA.
+
+The correct way to use Moose in a component in a both forward and backwards
+compatible way is:
+
+    package TestApp::Controller::Root;
+    use Moose;
+    BEGIN { extends 'Catalyst::Component' }; # Or ::Controller, or whatever
+
+Note that the C< extends > decleration needs to occur in a begin block for
+L<attributes> to operate correctly.
 
 =head2 Anonymous closures installed directly into the symbol table
 
@@ -50,6 +77,32 @@ install the closure using the appropriate metaclass. Example:
     my $metaclass = Moose::Meta::Class->initialize($package_name);
     $metaclass->add_method($method_name => sub { ... });
 
+=head2 Hooking into application setup
+
+To execute code during application startup the following snippet in MyApp.pm
+used to work:
+
+    sub setup {
+        my ($class, @args) = @_;
+        $class->NEXT::setup(@args);
+        ... # things to do after the actual setup
+    }
+
+With Catalyst 5.80 this won't work anymore. Because instead of using NEXT.pm it
+relies on Class::C3::Adopt::NEXT, which doesn't remember what methods it
+already called, like NEXT does and therefore goes into a deep recursion between
+MyApp::setup and Catalyst::setup.
+
+Moose method modifiers line C<< before|after|around 'setup => sub { ... }; >>
+won't work either because of backward compatibility issues related to plugin
+setup methods.
+
+The right way to do it is this:
+
+    after setup_finalize => sub {
+        ... # things to do after the actual setup
+    };
+
 =head2 Components whos new method returns false
 
 Previously if your new method returned a false value, 
@@ -105,17 +158,6 @@ Therefore the correct fix is to re-arrange your class' inheritance
 hierarchy so that the COMPONENT method you would like to inherit is
 the first COMPONENT method in your @ISA. 
 
-=head2 Assigning lists to accessors
-
-Accessors generated by Class::Accessor::Fast will, when multiple values
-are assigned to them, store a reference to a list automatically for you.
-
-This is not currently supported by MooseX::Emulate::Class::Accessor::Fast,
-and only the first value in the list will be stored.
-
-If you are relying on this behavior, and inheriting mk_accessors from a
-Catalyst component, then your code will fail.
-
 =head1 WARNINGS
 
 =head2 Methods in Catalyst::Dispatcher