NAME¶
Catalyst::Upgrading - Instructions for upgrading to the latest Catalyst
Upgrading to Catalyst 5.90060¶
Starting in the v5.90059_001 development release, the regexp dispatch type is no
longer automatically included as a dependency. If you are still using this
dispatch type, you need to add Catalyst::DispatchType::Regex into your build
system.
The standalone distribution of Regexp will be supported for the time being, but
should we find that supporting it prevents us from moving Catalyst forward in
necessary ways, we reserve the right to drop that support. It is highly
recommended that you use this last stage of deprecation to change your code.
Upgrading to Catalyst 5.90040¶
Catalyst::Plugin::Unicode::Encoding is now core¶
The previously stand alone Unicode support module
Catalyst::Plugin::Unicode::Encoding has been brought into core as a default
plugin. Going forward, all you need is to add a configuration setting for the
encoding type. For example:
package Myapp::Web;
use Catalyst;
__PACKAGE__->config( encoding => 'UTF-8' );
Please note that this is different from the old stand alone plugin which applied
"UTF-8" encoding by default (that is, if you did not set an explicit
"encoding" configuration value, it assumed you wanted UTF-8). In
order to preserve backwards compatibility you will need to explicitly turn it
on via the configuration setting. THIS MIGHT CHANGE IN THE FUTURE, so please
consider starting to test your application with proper UTF-8 support and
remove all those crappy hacks you munged into the code because you didn't know
the Plugin existed :)
For people that are using the Plugin, you will note a startup warning suggesting
that you can remove it from the plugin list. When you do so, please remember
to add the configuration setting, since you can no longer rely on the default
being UTF-8. We'll add it for you if you continue to use the stand alone
plugin and we detect this, but this backwards compatibility shim will likely
be removed in a few releases (trying to clean up the codebase after all).
If you have trouble with any of this, please bring it to the attention of the
Catalyst maintainer group.
basic async and event loop support¶
This version of Catalyst offers some support for using AnyEvent and IO::Async
event loops in your application. These changes should work fine for most
applications however if you are already trying to perform some streaming,
minor changes in this area of the code might affect your functionality. Please
see Catalyst::Response\write_fh for more and for a basic example.
We consider this feature experimental. We will try not to break it, but we
reserve the right to make necessary changes to fix major issues that people
run into when the use this functionality in the wild.
Upgrading to Catalyst 5.90030¶
Regex dispatch type is deprecated.¶
The Regex dispatchtype (Catalyst::DispatchType::Regex) has been deprecated.
You are encouraged to move your application to Chained dispatch
(Catalyst::DispatchType::Chained).
If you cannot do so, please add a dependency to Catalyst::DispatchType::Regex to
your application's Makefile.PL
Upgrading to Catalyst 5.9¶
The major change is that Plack, a toolkit for using the PSGI specification, now
replaces most of the subclasses of Catalyst::Engine. If you are using one of
the standard subclasses of Catalyst::Engine this should be a straightforward
upgrade for you. It was a design goal for this release to preserve as much
backwards compatibility as possible. However, since Plack is different from
Catalyst::Engine, it is possible that differences exist for edge cases.
Therefore, we recommend that care be taken with this upgrade and that testing
should be greater than would be the case with a minor point update. Please
inform the Catalyst developers of any problems so that we can fix them and
incorporate tests.
It is highly recommended that you become familiar with the Plack ecosystem and
documentation. Being able to take advantage of Plack development and
middleware is a major bonus to this upgrade. Documentation about how to take
advantage of Plack::Middleware by writing your own ".psgi" file is
contained in Catalyst::PSGI.
If you have created a custom subclass of <Catalyst:Engine>, you will need
to convert it to be a subclass of Plack::Handler.
If you are using the Plack engine, Catalyst::Engine::PSGI, this new release
supersedes that code.
If you are using a subclass of Catalyst::Engine that is aimed at nonstandard or
internal/testing uses, such as Catalyst::Engine::Embeddable, you should still
be able to continue using that engine.
Advice for specific subclasses of Catalyst::Engine follows:
Upgrading the FastCGI Engine¶
No upgrade is needed if your myapp_fastcgi.pl script is already upgraded to use
Catalyst::Script::FastCGI.
Upgrading the mod_perl / Apache Engines¶
The engines that are built upon the various iterations of mod_perl,
Catalyst::Engine::Apache::MP13 (for mod_perl 1, and Apache 1.x) and
Catalyst::Engine::Apache2::MP20 (for mod_perl 2, and Apache 2.x), should be
seamless upgrades and will work using Plack::Handler::Apache1 or
Plack::Handler::Apache2 as required.
Catalyst::Engine::Apache2::MP19, however, is no longer supported, as Plack does
not support mod_perl version 1.99. This is unlikely to be a problem for
anyone, as 1.99 was a brief beta-test release for mod_perl 2, and all users of
mod_perl 1.99 are encouraged to upgrade to a supported release of Apache 2 and
mod_perl 2.
Upgrading the HTTP Engine¶
The default development server that comes with the Catalyst distribution should
continue to work as expected with no changes as long as your
"myapp_server" script is upgraded to use Catalyst::Script::HTTP.
Upgrading the CGI Engine¶
If you were using Catalyst::Engine::CGI there is no upgrade needed if your
myapp_cgi.pl script is already upgraded to use Catalyst::Script::CGI.
Upgrading Catalyst::Engine::HTTP::Prefork¶
If you were using Catalyst::Engine::HTTP::Prefork then Starman is automatically
loaded. You should (at least) change your "Makefile.PL" to depend on
Starman.
You can regenerate your "myapp_server.pl" script with
"catalyst.pl" and implement a "MyApp::Script::Server"
class that looks like this:
package MyApp::Script::Server;
use Moose;
use namespace::autoclean;
extends 'CatalystX::Script::Server::Starman';
1;
This takes advantage of the new script system, and will add a number of options
to the standard server script as extra options are added by Starman.
More information about these options can be seen at "SYNOPSIS" in
CatalystX::Script::Server::Starman.
An alternate route to implement this functionality is to write a simple .psgi
file for your application, and then use the plackup utility to start the
server.
Upgrading the PSGI Engine¶
If you were using Catalyst::Engine::PSGI, this new release supersedes this
engine in supporting Plack. By default the Engine is now always Plack. As a
result, you can remove the dependency on Catalyst::Engine::PSGI in your
"Makefile.PL".
Applications that were using Catalyst::Engine::PSGI previously should entirely
continue to work in this release with no changes.
However, if you have an "app.psgi" script, then you no longer need to
specify the PSGI engine. Instead, the Catalyst application class now has a new
method "psgi_app" which returns a PSGI compatible coderef which you
can wrap in the middleware of your choice.
Catalyst will use the .psgi for your application if it is located in the
"home" directory of the application.
For example, if you were using Catalyst::Engine::PSGI in the past, you will have
written (or generated) a "script/myapp.psgi" file similar to this
one:
use Plack::Builder;
use MyCatalytApp;
MyCatalystApp->setup_engine('PSGI');
builder {
enable ... # enable your desired middleware
sub { MyCatalystApp->run(@_) };
};
Instead, you now say:
use Plack::Builder;
use MyCatalystApp;
builder {
enable ... #enable your desired middleware
MyCatalystApp->psgi_app;
};
In the simplest case:
MyCatalystApp->setup_engine('PSGI');
my $app = sub { MyCatalystApp->run(@_) }
becomes
my $app = MyCatalystApp->psgi_app(@_);
NOT:
my $app = sub { MyCatalystApp->psgi_app(@_) };
# If you make ^^ this mistake, your app won't work, and will confuse the hell out of you!
You can now move "script/myapp.psgi" to "myapp.psgi", and
the built-in Catalyst scripts and your test suite will start using your .psgi
file.
NOTE: If you rename your .psgi file without these modifications, then any
tests run via Catalyst::Test will not be compatible with the new release, and
will result in the development server starting, rather than the expected test
running.
NOTE: If you are directly accessing "$c->req->env" to get
the PSGI environment then this accessor is moved to
"$c->engine->env", you will need to update your code.
Engines which are known to be broken¶
The following engines
DO NOT work as of Catalyst version 5.9. The core
team will be happy to work with the developers and/or users of these engines
to help them port to the new Plack/Engine system, but for now, applications
which are currently using these engines
WILL NOT run without
modification to the engine code.
- Catalyst::Engine::Wx
- Catalyst::Engine::Zeus
- Catalyst::Engine::JobQueue::POE
- Catalyst::Engine::XMPP2
- Catalyst::Engine::SCGI
Engines with unknown status¶
The following engines are untested or have unknown compatibility. Reports are
highly encouraged:
- Catalyst::Engine::Mojo
- Catalyst::Engine::Server (marked as Deprecated)
- Catalyst::Engine::HTTP::POE (marked as Deprecated)
Plack functionality¶
See Catalyst::PSGI.
Tests in 5.9¶
Tests should generally work the same in Catalyst 5.9, but there are some
differences.
Previously, if using Catalyst::Test and doing local requests (against a local
server), if the application threw an exception then this exception propagated
into the test.
This behavior has been removed, and now a 500 response will be returned to the
test. This change standardizes behavior, so that local test requests behave
similarly to remote requests.
Upgrading to Catalyst 5.80¶
Most applications and plugins should run unaltered on Catalyst 5.80.
However, a lot of refactoring work has taken place, and several changes have
been made which could cause incompatibilities. If your application or plugin
is using deprecated code, or relying on side effects, then you could have
issues upgrading to this release.
Most issues found with existing components have been easy to solve. This
document provides a complete description of behavior changes which may cause
compatibility issues, and of new Catalyst warnings which might be unclear.
If you think you have found an upgrade-related issue which is not covered in
this document, please email the Catalyst list to discuss the problem.
Moose features¶
Application class roles¶
You can only apply method modifiers after the application's
"->setup" method has been called. This means that modifiers will
not work with methods run during the call to "->setup".
See Catalyst::Manual::ExtendingCatalyst for more information about using Moose
in your applications.
Controller actions in Moose roles¶
You can use MooseX::MethodAttributes::Role if you want to declare actions inside
Moose roles.
Using Moose in Components¶
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
See "Components which inherit from Moose::Object before
Catalyst::Component".
Known backwards compatibility breakages¶
Applications in a single file¶
Applications must be in their own file, and loaded at compile time. This issue
generally only affects the tests of CPAN distributions. Your application will
fail if you try to define an application inline in a block, and use plugins
which supply a " new " method, then use that application latter in
tests within the same file.
This is due to the fact that Catalyst is inlining a new method on your
application class allowing it to be compatible with Moose. The method used to
do this changed in 5.80004 to avoid the possibility of reporting an 'Unknown
Error' if your application failed to compile.
Issues with Class::C3¶
Catalyst 5.80 uses the Algorithm::C3 method dispatch order. This is built into
Perl 5.10, and comes via Class::C3 for Perl 5.8. This replaces NEXT with
Class::C3::Adopt::NEXT, forcing all components to resolve methods using C3,
rather than the unpredictable dispatch order of NEXT.
This issue manifests itself by your application failing to start due to an error
message about having a non-linear @ISA.
The Catalyst plugin most often causing this is
Catalyst::Plugin::Session::Store::FastMmap - if you are using this plugin and
see issues, then please upgrade your plugins, as it has been fixed. Note that
Makefile.PL in the distribution will warn about known incompatible components.
This issue can, however, be found in your own application - the only solution is
to go through each base class of the class the error was reported against,
until you identify the ones in conflict, and resolve them.
To be able to generate a linear @ISA, the list of superclasses for each class
must be resolvable using the C3 algorithm. Unfortunately, when superclasses
are being used as mixins (to add functionality used in your class), and with
multiple inheritance, it is easy to get this wrong.
Most common is the case of:
package Component1; # Note, this is the common case
use base qw/Class::Accessor::Fast Class::Data::Inheritable/;
package Component2; # Accidentally saying it this way causes a failure
use base qw/Class::Data::Inheritable Class::Accessor::Fast/;
package GoesBang;
use base qw/Component1 Component2/;
Any situation like this will cause your application to fail to start.
For additional documentation about this issue, and how to resolve it, see
Class::C3::Adopt::NEXT.
Components which inherit from Moose::Object before Catalyst::Component¶
Moose components which say:
package TestApp::Controller::Example;
use Moose;
extends qw/Moose::Object Catalyst::Component/;
to use the constructor provided by Moose, while working (if you do some hacks
with the " BUILDARGS " method), will not work with Catalyst 5.80 as
"Catalyst::Component" inherits from "Moose::Object", and
so @ISA fails to linearize.
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 " extends " declaration needs to occur in a begin block
for attributes to operate correctly.
This way you do not inherit directly from "Moose::Object" yourself.
Having components which do not inherit their constructor from
"Catalyst::Component" is
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, and
deal with it appropriately.
You also don't get the Moose::Object constructor, and therefore attribute
initialization will not work as normally expected. If you want to use Moose
attributes, then they need to be made lazy to correctly initialize.
Note that this only applies if your component needs to maintain component
backwards compatibility for Catalyst versions before 5.71001 - in 5.71001
attributes work as expected, and the BUILD method is called normally (although
BUILDARGS is not).
If you depend on Catalyst 5.8, then
all Moose features work as expected.
You will also see this issue if you do the following:
package TestApp::Controller::Example;
use Moose;
use base 'Catalyst::Controller';
as " use base " appends to @ISA.
use Moose in MyApp
Similar to the above, this will also fail:
package MyApp;
use Moose;
use Catalyst qw/
ConfigLoader
/;
__PACKAGE__->setup;
If you need to use Moose in your application class (e.g. for method modifiers
etc.) then the correct technique is:
package MyApp;
use Moose;
use Catalyst;
extends 'Catalyst';
__PACKAGE__->config( name => 'MyApp' );
__PACKAGE__->setup(qw/
ConfigLoader
/);
Anonymous closures installed directly into the symbol table¶
If you have any code which installs anonymous subroutine references directly
into the symbol table, you may encounter breakages. The simplest solution is
to use Sub::Name to name the subroutine. Example:
# Original code, likely to break:
my $full_method_name = join('::', $package_name, $method_name);
*$full_method_name = sub { ... };
# Fixed Code
use Sub::Name 'subname';
my $full_method_name = join('::',$package_name, $method_name);
*$full_method_name = subname $full_method_name, sub { ... };
Additionally, you can take advantage of Catalyst's use of Class::MOP and install
the closure using the appropriate metaclass. Example:
use Class::MOP;
my $metaclass = Moose::Meta::Class->initialize($package_name);
$metaclass->add_method($method_name => sub { ... });
Hooking into application setup¶
To execute code during application start-up, 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 Catalyst no longer uses
NEXT.pm for method resolution. The functionality was only ever originally
operational as NEXT remembers what methods have already been called, and will
not call them again.
Using this now causes infinite recursion between MyApp::setup and
Catalyst::setup, due to other backwards compatibility issues related to how
plugin setup works. Moose method modifiers like "before|after|around
setup => sub { ... };" also will not operate correctly on the setup
method.
The right way to do it is this:
after setup_finalize => sub {
... # things to do after the actual setup
};
The setup_finalize hook was introduced as a way to avoid this issue.
Components with a new method which returns false¶
Previously, if you had a component which inherited from Catalyst::COMPONENT, but
overrode the new method to return false, then your class's configuration would
be blessed into a hash on your behalf, and this would be returned from the
COMPONENT method.
This behavior makes no sense, and so has been removed. Implementing your own
" new " method in components is
highly discouraged. Instead,
you should inherit the new method from Catalyst::Component, and use Moose's
BUILD functionality and/or Moose attributes to perform any construction work
necessary for your class.
Won't work due to a limitation of Moose. This is currently being fixed inside
Moose.
Class::Data::Inheritable side effects¶
Previously, writing to a class data accessor would copy the accessor method down
into your package.
This behavior has been removed. While the class data is still stored per-class,
it is stored on the metaclass of the class defining the accessor.
Therefore anything relying on the side effect of the accessor being copied down
will be broken.
The following test demonstrates the problem:
{
package BaseClass;
use base qw/Class::Data::Inheritable/;
__PACKAGE__->mk_classdata('foo');
}
{
package Child;
use base qw/BaseClass/;
}
BaseClass->foo('base class');
Child->foo('sub class');
use Test::More;
isnt(BaseClass->can('foo'), Child->can('foo'));
Extending Catalyst::Request or other classes in an ad hoc manner using mk_accessors¶
Previously, it was possible to add additional accessors to Catalyst::Request (or
other classes) by calling the mk_accessors class method.
This is no longer supported - users should make a subclass of the class whose
behavior they would like to change, rather than globally polluting the
Catalyst objects.
Confused multiple inheritance with Catalyst::Component::COMPONENT¶
Previously, Catalyst's COMPONENT method would delegate to the method on the
right hand side, which could then delegate back again with NEXT. This is poor
practice, and in addition, makes no sense with C3 method dispatch order, and
is therefore no longer supported.
If a COMPONENT method is detected in the inheritance hierarchy to the right hand
side of Catalyst::Component::COMPONENT, then the following warning message
will be emitted:
There is a COMPONENT method resolving after Catalyst::Component
in ${next_package}.
The correct fix is to re-arrange your class's inheritance hierarchy so that the
COMPONENT method you would like to inherit is the first (left-hand most)
COMPONENT method in your @ISA.
Development server relying on environment variables¶
Previously, the development server would allow propagation of system environment
variables into the request environment, this has changed with the adoption of
Plack. You can use Plack::Middleware::ForceEnv to achieve the same effect.
WARNINGS¶
Actions in your application class¶
Having actions in your application class will now emit a warning at application
startup as this is deprecated. It is highly recommended that these actions are
moved into a MyApp::Controller::Root (as demonstrated by the scaffold
application generated by catalyst.pl).
This warning, also affects tests. You should move actions in your test, creating
a myTest::Controller::Root, like the following example:
package MyTest::Controller::Root;
use strict;
use warnings;
use parent 'Catalyst::Controller';
__PACKAGE__->config(namespace => '');
sub action : Local {
my ( $self, $c ) = @_;
$c->do_something;
}
1;
::[MVC]:: naming scheme¶
Having packages called MyApp::[MVC]::XX is deprecated and can no longer be
generated by catalyst.pl
This is still supported, but it is recommended that you rename your application
components to Model/View/Controller.
A warning will be issued at application startup if the ::[MVC]:: naming scheme
is in use.
Catalyst::Base¶
Any code using Catalyst::Base will now emit a warning; this module will be
removed in a future release.
Methods in Catalyst::Dispatcher¶
The following methods in Catalyst::Dispatcher are implementation details, which
may change in the 5.8X release series, and therefore their use is highly
deprecated.
- tree
- dispatch_types
- registered_dispatch_types
- method_action_class
- action_hash
- container_hash
The first time one of these methods is called, a warning will be emitted:
Class $class is calling the deprecated method Catalyst::Dispatcher::$public_method_name,
this will be removed in Catalyst 5.9
You should
NEVER be calling any of these methods from application code.
Plugin authors and maintainers whose plugins currently call these methods should
change to using the public API, or, if you do not feel the public API
adequately supports your use case, please email the development list to
discuss what API features you need so that you can be appropriately supported.
Class files with names that don't correspond to the packages they define¶
In this version of Catalyst, if a component is loaded from disk, but no symbols
are defined in that component's name space after it is loaded, this warning
will be issued:
require $class was successful but the package is not defined.
This is to protect against confusing bugs caused by mistyping package names, and
will become a fatal error in a future version.
Please note that 'inner packages' (via Devel::InnerPackage) are still fully
supported; this warning is only issued when component file naming does not map
to
any of the packages defined within that component.
$c->plugin method¶
Calling the plugin method is deprecated, and calling it at run time is
highly deprecated.
Instead you are recommended to use Catalyst::Model::Adaptor or similar to
compose the functionality you need outside of the main application name space.
Calling the plugin method will not be supported past Catalyst 5.81.