Enums

Symfony 5.4 landed November 29, 2021, same day as Symfony 6.0 and one day after PHP 8.1 was released. Not a coincidence. 5.4 is the LTS, and its job is to carry as much of 6.0’s feature set as possible while keeping 5.x compatibility intact. It’s also the first Symfony release that actually understands PHP 8.1 features. Enum support PHP 8.1 introduced native enums. Symfony 5.4 embraces them immediately: enum Status: string { case Active = 'active'; case Inactive = 'inactive'; } The EnumType form type renders enums as select fields, no custom transformers needed. The validator understands backed enums. The serializer maps enum values to their backing type and back. Three components updated in one shot, which meant migrating codebases from pseudo-enum constants to real PHP 8.1 enums was actually pretty smooth. ...

PHP 8.1 released November 25th. It follows 8.0’s sweeping overhaul with something different: fewer features, but each one thought through rather than bolted on. Enums This is the one that changes codebases the moment you upgrade. Before 8.1, PHP enumerations were either class constants, strings, or integers with nothing enforcing them: // before: nothing stops Status::INVALID from being passed const ACTIVE = 'active'; const INACTIVE = 'inactive'; // after enum Status: string { case Active = 'active'; case Inactive = 'inactive'; } function activate(Status $status): void { ... } PHP enums are objects, not scalars. They support methods, interfaces, and constants. Backed enums (with a string or int value) serialize cleanly and map to database columns naturally. Pure enums (no backing type) enforce domain concepts without worrying about serialization. ...