Catalyst::Upgrading - Instructions for upgrading to the latest Catalyst
+=head1 Upgrading to Catalyst 5.90121
+
+A new C<log_stats> method has been added. This will only affect
+subclasses that have a method with this name added.
+
+=head1 Upgrading to Catalyst 5.90100
+
+We changed the way the middleware stash works so that it no longer localizes
+the PSGI env hashref. This was done to fix bugs where people set PSGI ENV hash
+keys and found them to disappear in certain cases. It also means that now if
+a sub applications sets stash variables, that stash will now bubble up to the
+parent application. This may be a breaking change for you since previous
+versions of this code did not allow that. A workaround is to explicitly delete
+stash keys in your sub application before returning control to the parent
+application.
+
+=head1 Upgrading to Catalyst 5.90097
+
+In older versions of Catalyst one could construct a L<URI> with a fragment (such as
+https://localhost/foo/bar#fragment) by using a '#' in the path or final argument, for
+example:
+
+ $c->uri_for($action, 'foo#fragment');
+
+This behavior was never documented and would break if using the Unicode plugin, or when
+adding a query to the arguments:
+
+ $c->uri_for($action, 'foo#fragment', +{ a=>1, b=>2});
+
+would define a fragment like "#fragment?a=1&b=2".
+
+When we introduced UTF-8 encoding by default in Catalyst 5.9008x this side effect behavior
+was broken since we started encoding the '#' when it was part of the URI path.
+
+In version 5.90095 and 5.90096 we attempted to fix this, but all we managed to do was break
+people with URIs that included '#' as part of the path data, when it was not expected to
+be a fragment delimiter.
+
+In general L<Catalyst> prefers an explicit specification rather than relying on side effects
+or domain specific mini languages. As a result we are now defining how to set a fragment
+for a URI via ->uri_for:
+
+ $c->uri_for($action_or_path, \@captures_or_args, @args, \$query, \$fragment);
+
+If you are relying on the previous side effect behavior your URLs will now encode the '#'
+delimiter, which is going to be a breaking change for you. You need to alter your code
+to match the new specification or modify uri_for for your local case. Patches to solve
+this are very welcomed, as long as they don't break existing test cases.
+
+B<NOTE> If you are using the string form of the first argument:
+
+ $c->uri_for('/foo/bar#baz')
+
+construction, we do not attempt to encode this and it will make a URL with a
+fragment of 'baz'.
+
+
+=head1 Upgrading to Catalyst 5.90095
+
+The method C<last_error> in L</Catalyst> was actually returning the first error. This has
+been fixed but there is a small chance it could be a breaking issue for you. If this gives
+you trouble changing to C<shift_errors> is the easiest workaround (although that does
+modify the error stack so if you are relying on that not being changed you should try something
+like @{$c->errors}[-1] instead. Since this method is relatively new and the cases when the
+error stack actually has more than one error in it, we feel the exposure is very low, but bug
+reports are very welcomed.
+
+=head1 Upgrading to Catalyst 5.90090
+
+L<Catalyst::Utils> has a new method 'inject_component' which works the same as the method of
+the same name in L<CatalystX::InjectComponent>. You should start converting any
+use of the non core method in your code as future changes to Catalyst will be
+synchronized to the core method first. We reserve the right to cease support
+of the non core version should we reach a point in time where it cannot be
+properly supported as an external module. Luckily this should be a trivial
+search and replace. Change all occurrences of:
+
+ CatalystX::InjectComponent->inject(...)
+
+Into
+
+ Catalyst::Utils::inject_component(...)
+
+and we expect everything to work the same (we'd consider it not working the same
+to be a bug, and please report it.)
+
+We also cored features from L<CatalystX::RoleApplicator> to compose a role into the
+request, response and stats classes. The main difference is that with L<CatalystX::RoleApplicator>
+you did:
+
+ package MyApp;
+
+ use Catalyst;
+ use CatalystX::RoleApplicator;
+
+ __PACKAGE__->apply_request_class_roles(
+ qw/My::Request::Role Other::Request::Role/);
+
+Whereas now we have three class attributes, 'request_class_traits', 'response_class_traits'
+and 'stats_class_traits', so you use like this (note this value is an ArrayRef)
+
+
+ package MyApp;
+
+ use Catalyst;
+
+ __PACKAGE__->request_class_traits([qw/
+ My::Request::Role
+ Other::Request::Role/]);
+
+(And the same for response_class_traits and stats_class_traits. We left off the
+traits for Engine, since that class does a lot less nowadays, and dispatcher. If you
+used those and can share a use case, we'd be likely to support them.
+
+Lastly, we have some of the feature from L<CatalystX::ComponentsFromConfig> in
+core. This should mostly work the same way in core, except for now the
+core version does not create an automatic base wrapper class for your configured
+components (it requires these to be catalyst components and injects them directly.
+So if you make heavy use of custom base classes in L<CatalystX::ComponentsFromConfig>
+you might need a bit of work to use the core version (although there is no reason
+to stop using L<CatalystX::ComponentsFromConfig> since it should continue to work
+fine and we'd consider issues with it to be bugs). Here's one way to map from
+L<CatalystX::ComponentsFromConfig> to core:
+
+In L<CatalystX::ComponentsFromConfig>:
+
+ MyApp->config(
+ 'Model::MyClass' => {
+ class => 'MyClass',
+ args => { %args },
+
+ });
+
+and now in core:
+
+ MyApp->config(
+ inject_components => {
+ 'Model::MyClass' => { from_component => 'My::Class' },
+ },
+ 'Model::MyClass' => {
+ %args
+ },
+ );
+
+Although the core behavior requires more code, it better separates concerns
+as well as plays more into core Catalyst expectations of how configuration should
+look.
+
+Also we added a new develop console mode only warning when you call a component
+with arguments that don't expect or do anything meaningful with those args. Its
+possible if you are logging debug mode in production (please don't...) this
+could add verbosity to those logs if you also happen to be calling for components
+and passing pointless arguments. We added this warning to help people not make this
+error and to better understand the component resolution flow.
+
=head1 Upgrading to Catalyst 5.90085
In this version of Catalyst we made a small change to Chained Dispatching so
application configuration setting "use_chained_args_0_special_case" to true and
that will revert you code to the previous behavior.
+=head2 More backwards compatibility options with UTF-8 changes
+
+In order to give better backwards compatibility with the 5.90080+ UTF-8 changes
+we've added several configuration options around control of how we try to decode
+your URL keywords / query parameters.
+
+C<do_not_decode_query>
+
+If true, then do not try to character decode any wide characters in your
+request URL query or keywords. Most readings of the relevant specifications
+suggest these should be UTF-* encoded, which is the default that L<Catalyst>
+will use, however if you are creating a lot of URLs manually or have external
+evil clients, this might cause you trouble. If you find the changes introduced
+in Catalyst version 5.90080+ break some of your query code, you may disable
+the UTF-8 decoding globally using this configuration.
+
+This setting takes precedence over C<default_query_encoding> and
+C<decode_query_using_global_encoding>
+
+C<default_query_encoding>
+
+By default we decode query and keywords in your request URL using UTF-8, which
+is our reading of the relevant specifications. This setting allows one to
+specify a fixed value for how to decode your query. You might need this if
+you are doing a lot of custom encoding of your URLs and not using UTF-8.
+
+This setting take precedence over C<decode_query_using_global_encoding>.
+
+C<decode_query_using_global_encoding>
+
+Setting this to true will default your query decoding to whatever your
+general global encoding is (the default is UTF-8).
+
+
=head1 Upgrading to Catalyst 5.90080
UTF8 encoding is now default. For temporary backwards compatibility, if this