UPGRADE FROM 4.1 to 4.2

Cache

Deprecated CacheItem::getPreviousTags(), use CacheItem::getMetadata() instead.

Config

Deprecated constructing a TreeBuilder without passing root node information.
Deprecated FileLoaderLoadException, use LoaderLoadException instead.

Console

Deprecated passing a command as a string to ProcessHelper::run(), pass the command as an array of arguments instead.

Before:

$processHelper->run($output, 'ls -l');

After:

$processHelper->run($output, array('ls', '-l'));

// alternatively, when a shell wrapper is required
$processHelper->run($output, Process::fromShellCommandline('ls -l'));

DoctrineBridge

The lazy attribute on doctrine.event_listener tags was removed. Listeners are now lazy by default. So any lazy attributes can safely be removed from those tags.

Form

Deprecated calling FormRenderer::searchAndRenderBlock for fields which were already rendered. Instead of expecting such calls to return empty strings, check if the field has already been rendered.

Before:

{% for field in fieldsWithPotentialDuplicates %}
   {{ form_widget(field) }}
{% endfor %}

After:

{% for field in fieldsWithPotentialDuplicates if not field.rendered %}
   {{ form_widget(field) }}
{% endfor %}

Process

Deprecated the Process::setCommandline() and the PhpProcess::setPhpBinary() methods.

Deprecated passing commands as strings when creating a Process instance.

Before:

$process = new Process('ls -l');

After:

$process = new Process(array('ls', '-l'));

// alternatively, when a shell wrapper is required
$process = Process::fromShellCommandline('ls -l');

FrameworkBundle

The framework.router.utf8 configuration option has been added. If your app's charset is UTF-8 (see kernel's getCharset() method), it is recommended to set it to true: this will generate 404s for non-UTF-8 URLs, which are incompatible with you app anyway, and will allow dumping optimized routers and using Unicode classes in requirements.

Messenger

The handle method of the Symfony\Component\Messenger\Middleware\ValidationMiddleware and Symfony\Component\Messenger\Asynchronous\Middleware\SendMessageMiddleware middlewares now requires an Envelope object to be given (because they implement the EnvelopeAwareInterface). When using these middleware with the provided MessageBus, you will not have to do anything. If you use the middlewares any other way, you can use Envelope::wrap($message) to create an envelope for your message.

Security

Using the has_role() function in security expressions is deprecated, use the is_granted() function instead.
Not returning an array of 3 elements from FirewallMapInterface::getListeners() is deprecated, the 3rd element must be an instance of LogoutListener or null.
Passing custom class names to the Symfony\Component\Security\Core\Authentication\AuthenticationTrustResolver to define custom anonymous and remember me token classes is deprecated. To use custom tokens, extend the existing Symfony\Component\Security\Core\Authentication\Token\AnonymousToken or Symfony\Component\Security\Core\Authentication\Token\RememberMeToken.
Accessing the user object that is not an instance of UserInterface from Security::getUser() is deprecated.

SecurityBundle

Passing a FirewallConfig instance as 3rd argument to the FirewallContext constructor is deprecated, pass a LogoutListener instance instead.
Using the security.authentication.trust_resolver.anonymous_class and security.authentication.trust_resolver.rememberme_class parameters to define the token classes is deprecated. To use custom tokens extend the existing AnonymousToken and RememberMeToken.

Serializer

Relying on the default value (false) of the "as_collection" option is deprecated since 4.2. You should set it to false explicitly instead as true will be the default value in 5.0.

Uh oh!