New in Symfony 3.4: HTTP Immutable Responses

Symfony 3.4 will include support for HTTP Immutable Responses thanks to the new immutable option of the Cache-Control directive.

New in Symfony 3.4: Groups support for the Valid constraint

Symfony 3.4 adds support for validation groups in the Valid constraint, so you can partially validate the embedded objects.

New in Symfony 3.4: Better console exceptions

Symfony 3.4 improves the exceptions displayed in the console to include by default the exact file and line number where the exception occurred.

New in Symfony 3.4: User impersonation improvements

Symfony 3.4 improves the user impersonation feature of the Symfony component to make it easier to debug.

New in Symfony 3.4: Improved security listeners

In Symfony 3.4, security listeners are lazy loaded to improve performance. In addition, the Symfony Profiler has been updated to show all the information about security listeners.

New in Symfony 3.4: Added support for XLIFF 2.0 notes

Symfony 3.4 adds support for XLIFF 2.0 notes, which allow to store end user comments and annotations about translations.

New in Symfony 3.4: Prefix all controller route names

In Symfony 3.4, the @Route annotation can define a prefix for the names of all the routes defined in the same controller class.

New in Symfony 3.4: Lazy commands

In Symfony 3.4, console commands can be lazy-loaded, so the application doesn't have to instantiate all of them when running any command.

New in Symfony 3.4: Stopwatch improvements

In Symfony 3.4, the Stopwatch component allows to reset all its time measures and removes the sub-millisecond restriction to allow time measures with arbitrary precision.

New in Symfony 3.4: Validator information in the Symfony profiler

In Symfony 3.4, the web debug toolbar and the profiler will include a new panel to collect information about validator calls.