New in Symfony 3.4: Bootstrap 4 form theme

Symfony 3.4 adds a new form theme for Bootstrap 4, the most popular front-end component library.

New in Symfony 3.4: Argon2i password hasher

Symfony 3.4 includes an Argon2i password hasher , a modern alternative to Bcrypt natively supported by PHP 7.2.

New in Symfony 3.4: Default request context for assets

Symfony 3.4 provides new configuration options so you can generate the right URL for assets out of the HTTP context, for example in a command console.

New in Symfony 3.4: Deprecated bundle inheritance

Symfony 3.4 deprecates bundle inheritance, but Symfony still provides lots of alternatives to override the resources of third-party bundles in your application.

New in Symfony 3.4: Better code coverage reports

Symfony 3.4 adds a new CoverageListener to the PHPUnit Bridge component to create more precise code coverage reports.

New in Symfony 3.4: PHP-based configuration for services and routes

Symfony 3.4 introduces a new (optional) PHP-based configuration format to define routes and services using a fluent interface.

New in Symfony 3.4: Advanced environment variables

Symfony 3.4 allows to define the data type of the value stored in environment variables and also defines some operators to transform their values before using them.

New in Symfony 3.4: Improved comparison constraints

In Symfony 3.4, comparison constraints can get the value of any other property without having to define a full expression.

New in Symfony 3.4: Subscribing to events in the micro kernel

In Symfony 3.4, the MicroKernel trait can subscribe to events and handle them using methods defined in the kernel class.

New in Symfony 3.4: Deprecate configuration options

In Symfony 3.4, configuration options can be deprecated more easily to warn users about future changes.