NAME¶
Catalyst::Delta - Overview of changes between versions of Catalyst
DESCRIPTION¶
This is an overview of the user-visible changes to Catalyst between major
Catalyst releases.
VERSION 5.90060+¶
Catalyst::Log object autoflush on by default
Starting in 5.90065, the Catalyst::Log object has 'autoflush' which is on by
default. This causes all messages to be written to the log immediately instead
of at the end of startup and then at the end of each request. In order to
access the old behavior, you must now call:
$c->log->autoflush(0);
Deprecate Catalyst::Utils::ensure_class_loaded
Going forward we recommend you use Module::Runtime. In fact we will be
converting all uses of Class::Load to Module::Runtime. We will also convert
Catalyst::Utils\ensure_class_loaded to be based on Module::Runtime to allow
some time for you to update code, however at some future point this method
will be removed so you should stop using it now.
Support passing Body filehandles directly to your Plack server.
We changed the way we return body content (from response) to whatever Plack
handler you are using (Starman, FastCGI, etc.) We no longer always use the
streaming interface for the cases when the body is a simple scalar, object or
filehandle like. In those cases we now just pass the simple response on to the
plack handler. This might lead to some minor differences in how streaming is
handled. For example, you might notice that streaming starts properly
supporting chunked encoding when on a server that supports that, or that
previously missing headers (possible content-length) might appear suddenly
correct. Also, if you are using middleware like Plack::Middleware::XSendfile
and are using a filehandle that sets a readable path, your server might now
correctly handle the file (rather than as before where Catalyst would stream
it very likely very slowly).
In other words, some things might be meaninglessly different and some things
that were broken codewise but worked because of Catalyst being incorrect might
suddenly be really broken. The behavior is now more correct in that Catalyst
plays better with features that Plack offers but if you are making heavy use
of the streaming interface there could be some differences so you should test
carefully (this is probably not the vast majority of people). In particular if
you are developing using one server but deploying using a different one,
differences in what those server do with streaming should be noted.
Please see note below about changes to filehandle support and existing Plack
middleware to aid in backwards compatibility.
Distinguish between body null versus undef.
We also now more carefully distingush the different between a body set to '' and
a body that is undef. This might lead to situations where again you'll get a
content-length were you didn't get one before or where a supporting server
will start chunking output. If this is an issue you can apply the middleware
Plack::Middleware::BufferedStreaming or report specific problems to the dev
team.
More Catalyst Middleware
We have started migrating code in Catalyst to equivilent Plack Middleware when
such exists and is correct to do so. For example we now use
Plack::Middleware::ContentLength to determine content length of a response
when none is provided. This replaces similar code inlined with Catalyst The
main advantages to doing this is 1) more similar Catalyst core that is focused
on the Catalyst special sauce, 2) Middleware is more broadly shared so we
benefit from better collaboration with developers outside Catalyst, 3) In the
future you'll be able to change or trim the middleware stack to get additional
performance when you don't need all the checks and constraints.
Deprecate Filehandle like objects that do read but not getline
We also deprecated setting the response body to an object that does 'read' but
not 'getline'. If you are using a custom IO-Handle like object for response
you should verify that 'getline' is supported in your interface. Unless we
here this case is a major issue for people, we will be removing support in a
near future release of Catalyst. When the code encounters this it will issue a
warning. You also may run into this issue with MogileFS::Client which does
read but not getline. For now we will just warn when encountering such an
object and fallback to the previous behavior (where Catalyst::Engine itself
unrolls the filehandle and performs blocking streams). However this backwards
compatibility will be removed in an upcoming release so you should either
rewrite your custom filehandle objects to support getline or start using the
middleware that adapts read for getline
Plack::Middleware::AdaptFilehandleRead.
Response->headers become read-only after finalizing
Once the response headers are finalized, trying to change them is not allowed
(in the past you could change them and this would lead to unexpected results).
Officially deprecate Catalyst::Engine::PSGI
Catalyst::Engine::PSGI is also officially no longer supported. We will no long
run test cases against this and can remove backwards compatibility code for it
as deemed necessary for the evolution of the platform. You should simply
discontinue use of this engine, as Catalyst has been PSGI at the core for
several years.
Officially deprecate finding the PSGI $env anyplace other than
Request
A few early releases of Cataplack had the PSGI $env in Catalyst::Engine. Code
has been maintained here for backwards compatibility reasons. This is no
longer supported and will be removed in upcoming release, so you should update
your code and / or upgrade to a newer version of Catalyst
Deprecate setting Response->body after using write/write_fh
Setting $c->res->body to a filehandle after using $c->res->write or
$c->res->write_fh is no longer considered allowed, since we can't send
the filehandle to the underlying Plack handler. For now we will continue to
support setting body to a simple value since this is possible, but at some
future release a choice to use streaming indicates that you will do so for the
rest of the request.
VERSION 5.90053¶
We are now clarifying the behavior of log, plugins and configuration during the
setup phase. Since Plugins might require a log during setup, setup_log must
run BEFORE setup_plugins. This has the unfortunate side effect that anyone
using the popular ConfigLoader plugin will not be able to supply configuration
to custom logs since the configuration is not yet finalized when setup_log is
run (when using ConfigLoader, which is a plugin and is not loaded until
later.)
As a workaround, you can supply custom log configuration directly into the
configuration:
package MyApp;
use Catalyst;
__PACKAGE__->config(
my_custom_log_info => { %custom_args },
);
__PACKAGE__->setup;
If you wish to configure the custom logger differently based on ENV, you can
try:
package MyApp;
use Catalyst;
use Catalyst::Utils;
__PACKAGE__->config(
Catalyst::Utils::merge_hashes(
+{ my_custom_log_info => { %base_custom_args } },
+{ do __PACKAGE__->path_to( $ENV{WHICH_CONF}."_conf.pl") },
),
);
__PACKAGE__->setup;
Or create a standalone Configuration class that does the right thing.
Basically if you want to configure a logger via Catalyst global configuration
you can't use ConfigLoader because it will always be loaded too late to be of
any use. Patches and workaround options welcomed!
VERSION 5.9XXXX 'cataplack'¶
The Catalyst::Engine sub-classes have all been removed and deprecated, to be
replaced with Plack handlers.
Plack is an implementation of the PSGI specification, which is a standard
interface between web servers and application frameworks.
This should be no different for developers, and you should not have to migrate
your applications unless you are using a custom engine already.
This change benefits Catalyst significantly by reducing the amount of code
inside the framework, and means that the framework gets upstream bug fixes in
Plack, and automatically gains support for any web server which a PSGI
compliant handler is written for.
It also allows you more flexibility with your application, and allows the use of
cross web framework 'middleware'.
Developers are recommended to read Catalyst::Upgrading for notes about
upgrading, especially if you are using an unusual deployment method.
Documentation for how to take advantage of PSGI can be found in Catalyst::PSGI,
and information about deploying your application has been moved to
Catalyst::Manual::Deployment.
Updated modules:
A number of modules have been updated to pass their tests or not produce
deprecation warnings with the latest version of Catalyst. It is recommended
that you upgrade any of these that you are using after installing this version
of Catalyst.
These extensions are:
- Catalyst::Engine::HTTP::Prefork
- This is now deprecated, see Catalyst::Upgrading.
- Test::WWW::Mechanize::Catalyst
- Has been updated to not produce deprecation warnings, upgrade
recommended.
- Catalyst::ActionRole::ACL
- Has been updated to fix failing tests (although older versions still
function perfectly with this version of Catalyst).
- Catalyst::Plugin::Session::Store::DBIC
- Has been updated to fix failing tests (although older versions still
function perfectly with this version of Catalyst).
- Catalyst::Plugin::Authentication
- Has been updated to fix failing tests (although older versions still
function perfectly with this version of Catalyst).
PREVIOUS VERSIONS¶
VERSION 5.8XXXX 'catamoose'¶
Deprecations
Please see Catalyst::Upgrading for a full description of how changes in the
framework may affect your application.
Below is a brief list of features which have been deprecated in this release:
- ::[MVC]:: style naming scheme has been deprecated and will warn
- NEXT is deprecated for all applications and components, use
MRO::Compat
- Dispatcher methods which are an implementation detail made private, public
versions now warn.
- MyApp->plugin method is deprecated, use Catalyst::Model::Adaptor
instead.
- __PACKAGE__->mk_accessors() is supported for backwards
compatibility only, use Moose attributes instead in new code.
- Use of Catalyst::Base now warns
New features
Dispatcher
- Fix forwarding to Catalyst::Action objects.
- Add the dispatch_type method
Restarter
The development server restarter has been improved to be compatible with
immutable Moose classes, and also to optionally use
B::Hooks::OP::Check::StashChange to handle more complex application layouts
correctly.
$c->uri_for_action method.
Give a private path to the Catalyst action you want to create a URI for.
Logging
Log levels have been made additive.
Catalyst::Test
- Change to use Sub::Exporter.
- Support mocking multiple virtual hosts
- New methods like action_ok and action_redirect to write more compact
tests
Catalyst::Response
- •
- New print method which prints @data to the output stream, separated by $,.
This lets you pass the response object to functions that want to write to
an IO::Handle.
- •
- Added code method as an alias for "$res->status"
Consequences of the Moose back end
- •
- Components are fully compatible with Moose, and all Moose features, such
as method modifiers, attributes, roles, BUILD and BUILDARGS methods are
fully supported and may be used in components and applications.
- •
- Many reusable extensions which would previously have been plugins or base
classes are better implemented as Moose roles.
- •
- MooseX::MethodAttributes::Role::AttrContainer::Inheritable is used to
contain action attributes. This means that attributes are represented in
the MOP, and decouples action creation from attributes.
- •
- There is a reasonable API in Catalyst::Controller for working with and
registering actions, allowing a controller sub-class to replace subroutine
attributes for action declarations with an alternate syntax.
- •
- Refactored capturing of $app from Catalyst::Controller into
Catalyst::Component::ApplicationAttribute for easier reuse in other
components.
- •
- Your application class is forced to become immutable at the end of
compilation.
Bug fixes
- •
- Don't ignore SIGCHLD while handling requests with the development server,
so that system() and other ways of creating child processes work as
expected.
- •
- Fixes for FastCGI when used with IIS 6.0
- •
- Fix a bug in uri_for which could cause it to generate paths with multiple
slashes in them.
- •
- Fix a bug in Catalyst::Stats, stopping garbage being inserted into the
stats if a user calls begin => but no end