New in Symfony 3.4: Simpler injection of tagged services

Symfony 3.4 provides a simpler way to inject all services tagged with a specific tag, so you don't have to create a compiler pass just to do that.

New in Symfony 3.4: Form improvements

Symfony 3.4 adds new HTML5 form types ("tel" and "color"), new options for TimezoneType and support for callbacks in the delete_empty option.

New in Symfony 3.4: Defining compiler passes in the kernel

In Symfony 3.4, the kernel of the application can implement CompilerPassInterface to define a compiler pass in it.

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.