Symfony's Backward Compatibility Promise ensures smooth upgrades in your projects because it forbids backward compatibility breaks in minor releases. Instead of changing or removing existing features, we mark them as deprecated and change them in the next major Symfony version.
The UPGRADE-4.2.md document explains all deprecations in details and you'll see them too in the Web Debug Toolbar, the profiler and when running tests. This article summarizes the most important deprecations so you can start upgrading your Symfony 4 apps.
Contributed by
Yonel Ceruto
in #28891.
Storing the app templates in src/Resources/views/
is now deprecated. You
must store them in the directory defined in the twig.default_path
config
option in config/packages/twig.yaml
, which is templates/
by default.
Contributed by
Fabien Potencier
in #28809 and
#28810.
The KernelInterface::getName()
method and the kernel.name
parameter have
been deprecated. There's no alternative to them because this is a concept that
no longer makes sense in Symfony applications.
If you need a distinctive ID for the kernel of the application, you can use the
KernelInterface::getContainerClass()
method and the kernel.container_class
parameter.
Similarly, the getRootDir()
method and the kernel.root_dir
parameter
have been deprecated too. The alternative is to use the getProjectdir()
and
kernel.project_dir
method introduced in Symfony 3.3:
1 2 3 4 5 6 7 8 9 | # 'root_dir' is where the Kernel class is stored (src/ by default) and
# 'project_dir' is the main project directory
services:
_defaults:
bind:
# Before
$dataDir: '%kernel.root_dir%/../var/data/'
# After
$dataDir: '%kernel.project_dir%/var/data/'
|
Contributed by
Robin Chalas
in #28653.
The --env
and --no-debug
console options have been deprecated. The
alternative is to use some env vars:
1 2 3 4 5 | # Before
$ php bin/console command_name --env=test --no-debug
# After
$ APP_ENV=test APP_DEBUG=0 php bin/console command_name
|
In addition to changing the commands executed locally, you may need to check your deployment commands and the cron tasks defined in your production servers.
ContainerAwareCommand
¶
Contributed by
Robin Chalas
in #28415.
The ContainerAwareCommand
class has been deprecated. It was used in the past
to create commands extending from it so they had direct access to the app
service container. The alternative is to extend commands from the Command
class and use proper service injection in the command constructor, as explained
in the main article about the Symfony Console.
TIP: use the make:command
utility provided by the MakerBundle to
generate commands quickly and following the Symfony recommendations.
Controller
class¶
Contributed by
Samuel Roze
in #28243.
The base Controller
class is the optional class your controllers can extend
from to get access to some useful shortcut methods (such us $this->render()
).
This Controller
class has been deprecated in favor of AbstractController
.
The new AbstractController
base class has the same shortcuts but it's more
restrictive about services. You cannot use the $this->get()
shortcut to get
services. You must follow the modern practices of injecting services in your
controller constructor or in the controller action.
TIP: use the make:controller
utility provided by the MakerBundle to
generate controllers quickly and following the Symfony recommendations.
Contributed by
Nicolas Grekas
in #27821.
Passing commands as strings to the Process
class has been deprecated. The
alternative is to pass an array of the command parts (name, arguments, options):
1 2 3 4 5 6 7 | use Symfony\Component\Process\Process;
// Before
$process = new Process('ls -l');
// After
$process = new Process(['ls', '-l']);
|
Contributed by
Christian Flothmann
in #27476.
This deprecation won't affect directly to most developers because it's related to the configuration classes of dependency injection. However, you'll see lots of these deprecation messages because of the bundles used in your application.
Fixing this deprecation will be simple in most cases, so you may contribute a fix to your favorite third-party bundle:
1 2 3 4 5 6 7 8 9 10 | use Symfony\Component\Config\Definition\Builder\TreeBuilder;
// Before
$treeBuilder = new TreeBuilder();
$rootNode = $treeBuilder->root('acme_root');
$rootNode->...()->...()->...();
// After
$treeBuilder = new TreeBuilder('acme_root');
$treeBuilder->getRootNode()->...()->...()->...();
|
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