UPGRADE FROM 3.2 to 3.3

BrowserKit

The request method is dropped from POST to GET when the response status code is 301.

ClassLoader

The component is deprecated and will be removed in 4.0. Use Composer instead.

Console

Input::getOption() no longer returns the default value for options with value optional explicitly passed empty.

For:

protected function configure()
{
    $this
        // ...
        ->setName('command')
        ->addOption('foo', null, InputOption::VALUE_OPTIONAL, '', 'default')
     ;
}

protected function execute(InputInterface $input, OutputInterface $output)
{
    var_dump($input->getOption('foo'));
}

Before:

$ php console.php command
"default"

$ php console.php command --foo
"default"

$ php console.php command --foo ""
"default"

$ php console.php command --foo=
"default"

After:

$ php console.php command
"default"

$ php console.php command --foo
NULL

$ php console.php command --foo ""
""

$ php console.php command --foo=
""

The console.exception event and the related ConsoleExceptionEvent class have been deprecated in favor of the console.error event and the ConsoleErrorEvent class. The deprecated event and class will be removed in 4.0.
The SymfonyQuestionHelper::ask default validation has been deprecated and will be removed in 4.0. Apply validation using Question::setValidator instead.

Debug

The ContextErrorException class is deprecated. \ErrorException will be used instead in 4.0.

DependencyInjection

Autowiring services based on the types they implement is deprecated and won't be supported in version 4.0. Rename (or alias) your services to their FQCN id to make them autowirable.
The NullDumper class has been made final
[BC BREAK] _defaults and _instanceof are now reserved service names in Yaml configurations. Please rename any services with that names.
[BC BREAK] non-numeric keys in methods and constructors arguments have never been supported and are now forbidden. Please remove them if you happen to have one.
Service names that start with an underscore are deprecated in Yaml files and will be reserved in 4.0. Please rename any services with such names.

Autowiring-types have been deprecated, use aliases instead.

Before:

<service id="annotations.reader" class="Doctrine\Common\Annotations\AnnotationReader" public="false">
    <autowiring-type>Doctrine\Common\Annotations\Reader</autowiring-type>
</service>

After:

<service id="annotations.reader" class="Doctrine\Common\Annotations\AnnotationReader" public="false" />
<service id="Doctrine\Common\Annotations\Reader" alias="annotations.reader" public="false" />

The Reference and Alias classes do not make service identifiers lowercase anymore.
Case insensitivity of service identifiers is deprecated and will be removed in 4.0.
Using the PhpDumper with an uncompiled ContainerBuilder is deprecated and will not be supported anymore in 4.0.
Extending the containers generated by PhpDumper is deprecated and won't be supported in 4.0.
The DefinitionDecorator class is deprecated and will be removed in 4.0, use the ChildDefinition class instead.
The strict attribute in service arguments has been deprecated and will be removed in 4.0. The attribute is ignored since 3.0, so you can simply remove it.

EventDispatcher

The ContainerAwareEventDispatcher class has been deprecated. Use EventDispatcher with closure factories instead.

Finder

The ExceptionInterface has been deprecated and will be removed in 4.0.

Form

Using the "choices" option in CountryType, CurrencyType, LanguageType, LocaleType, and TimezoneType without overriding the choice_loader option has been deprecated and will be ignored in 4.0.

Before:

$builder->add('custom_locales', LocaleType::class, array(
    'choices' => $availableLocales,
));

After:

$builder->add('custom_locales', LocaleType::class, array(
    'choices' => $availableLocales,
    'choice_loader' => null,
));
// or
$builder->add('custom_locales', LocaleType::class, array(
    'choice_loader' => new CallbackChoiceLoader(function () {
        return $this->getAvailableLocales();
    }),
));

FrameworkBundle

[BC BREAK] The "framework.trusted_proxies" configuration option and the corresponding "kernel.trusted_proxies" parameter have been removed. Use the Request::setTrustedProxies() method in your front controller instead.
Not defining the type option of the framework.workflows.* configuration entries is deprecated. The default value will be state_machine in Symfony 4.0.
The Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\CompilerDebugDumpPass has been deprecated.
The Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\AddConsoleCommandPass has been deprecated. Use Symfony\Component\Console\DependencyInjection\AddConsoleCommandPass instead.
The Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\SerializerPass class has been deprecated and will be removed in 4.0. Use the Symfony\Component\Serializer\DependencyInjection\SerializerPass class instead.
The Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\FormPass class has been deprecated and will be removed in 4.0. Use the Symfony\Component\Form\DependencyInjection\FormPass class instead.
The Symfony\Bundle\FrameworkBundle\EventListener\SessionListener class has been deprecated and will be removed in 4.0. Use the Symfony\Component\HttpKernel\EventListener\SessionListener class instead.
The Symfony\Bundle\FrameworkBundle\EventListener\TestSessionListener class has been deprecated and will be removed in 4.0. Use the Symfony\Component\HttpKernel\EventListener\TestSessionListener class instead.
The Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\ConfigCachePass class has been deprecated and will be removed in 4.0. Use Symfony\Component\Config\DependencyInjection\ConfigCachePass class instead.
The Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\PropertyInfoPass class has been deprecated and will be removed in 4.0. Use the Symfony\Component\PropertyInfo\DependencyInjection\PropertyInfoPass class instead.
Class parameters related to routing have been deprecated and will be removed in 4.0.
- router.options.generator_class
- router.options.generator_base_class
- router.options.generator_dumper_class
- router.options.matcher_class
- router.options.matcher_base_class
- router.options.matcher_dumper_class
- router.options.matcher.cache_class
- router.options.generator.cache_class
The Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\ControllerArgumentValueResolverPass class has been deprecated and will be removed in 4.0. Use the Symfony\Component\HttpKernel\DependencyInjection\ControllerArgumentValueResolverPass class instead.
The Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\RoutingResolverPass class has been deprecated and will be removed in 4.0. Use the Symfony\Component\Routing\DependencyInjection\RoutingResolverPass class instead.
The server:run, server:start, server:stop and server:status console commands have been moved to a dedicated bundle. Require symfony/web-server-bundle in your composer.json and register Symfony\Bundle\WebServerBundle\WebServerBundle in your AppKernel to use them.
The Symfony\Bundle\FrameworkBundle\Translation\Translator constructor now takes the default locale as 3rd argument. Not passing it will trigger an error in 4.0.
The Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\AddValidatorInitializersPass class has been deprecated and will be removed in 4.0. Use the Symfony\Component\Validator\DependencyInjection\AddValidatorInitializersPass class instead.
The Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\AddConstraintValidatorsPass class has been deprecated and will be removed in 4.0. Use the Symfony\Component\Validator\DependencyInjection\AddConstraintValidatorsPass class instead.
The Symfony\Bundle\FrameworkBundle\DependencyInjection\Compiler\ValidateWorkflowsPass class has been deprecated and will be removed in 4.0. Use the Symfony\Component\Workflow\DependencyInjection\ValidateWorkflowsPass class instead.
The Symfony\Bundle\FrameworkBundle\Validator\ConstraintValidatorFactory class has been deprecated and will be removed in 4.0. Use Symfony\Component\Validator\ContainerConstraintValidatorFactory instead.

HttpFoundation

[BC BREAK] The Request::setTrustedProxies() method takes a new $trustedHeaderSet argument. See http://symfony.com/doc/current/components/http_foundation/trusting_proxies.html for more info.
The Request::setTrustedHeaderName() and Request::getTrustedHeaderName() methods are deprecated, use the RFC7239 Forwarded header, or the X-Forwarded-* headers instead.

HttpKernel

The Extension::addClassesToCompile() and Extension::getClassesToCompile() methods have been deprecated and will be removed in 4.0.
The Psr6CacheClearer::addPool() method has been deprecated. Pass an array of pools indexed by name to the constructor instead.
The LazyLoadingFragmentHandler::addRendererService() method has been deprecated and will be removed in 4.0.
The X-Status-Code header method of setting a custom status code in the response when handling exceptions has been removed. There is now a new GetResponseForExceptionEvent::allowCustomResponseCode() method instead, which will tell the Kernel to use the response code set on the event's response object.
The Kernel::getEnvParameters() method has been deprecated and will be removed in 4.0.
The SYMFONY__ environment variables have been deprecated and they will be no longer processed automatically by Symfony in 4.0. Use the %env()% syntax to get the value of any environment variable from configuration files instead.

Process

The ProcessUtils::escapeArgument() method has been deprecated, use a command line array or give env vars to the Process::start/run() method instead.
Not inheriting environment variables is deprecated.
Configuring proc_open() options is deprecated.
Configuring Windows and sigchild compatibility is deprecated - they will be always enabled in 4.0.
Extending Process::run(), Process::mustRun() and Process::restart() is deprecated and won't be supported in 4.0.

ProxyManager

[BC BREAK] The ProxyDumper class has been made final

Security

The RoleInterface has been deprecated. Extend the Symfony\Component\Security\Core\Role\Role class in your custom role implementations instead.
The LogoutUrlGenerator::registerListener() method will expect a 6th string $context = null argument in 4.0. Define the argument when overriding this method.
The AccessDecisionManager::setVoters() method has been deprecated. Pass the voters to the constructor instead.

SecurityBundle

The FirewallContext::getContext() method has been deprecated and will be removed in 4.0. Use the getListeners() and/or getExceptionListener() method instead.
The FirewallMap::$map and $container properties have been deprecated and will be removed in 4.0.
The UserPasswordEncoderCommand command expects to be registered as a service and its constructor arguments fully provided. Registering by convention the command or commands extending it is deprecated and will not be allowed anymore in 4.0.
UserPasswordEncoderCommand::getContainer() is deprecated, and this class won't extend ContainerAwareCommand nor implement ContainerAwareInterface anymore in 4.0.
[BC BREAK] Keys of the users node for in_memory user provider are no longer normalized.

Serializer

Extending ChainDecoder, ChainEncoder, ArrayDenormalizer is deprecated and won't be supported in 4.0.

TwigBridge

The TwigRendererEngine::setEnvironment() method has been deprecated and will be removed in 4.0. Pass the Twig Environment as second argument of the constructor instead.

TwigBundle

The ContainerAwareRuntimeLoader class has been deprecated and will be removed in 4.0. Use the Twig Twig_ContainerRuntimeLoader class instead.

Workflow

Deprecated class name support in WorkflowRegistry::add() as second parameter. Wrap the class name in an instance of ClassInstanceSupportStrategy instead.

Yaml

Starting an unquoted string with a question mark followed by a space is deprecated and will throw a ParseException in Symfony 4.0.
Deprecated support for implicitly parsing non-string mapping keys as strings. Mapping keys that are no strings will lead to a ParseException in Symfony 4.0. Use quotes to opt-in for keys to be parsed as strings.

Before:
```
$yaml = <<<YAML
null: null key
true: boolean true
2.0: float key
YAML;

Yaml::parse($yaml);
```
After:
```
$yaml = <<<YAML
"null": null key
"true": boolean true
"2.0": float key
YAML;

Yaml::parse($yaml);
```
Omitting the key of a mapping is deprecated and will throw a ParseException in Symfony 4.0.
The constructor arguments $offset, $totalNumberOfLines and $skippedLineNumbers of the Parser class are deprecated and will be removed in 4.0

Uh oh!