PSR12

PSR-12 is a PHP coding style guide published by the PHP Framework Interop Group (PHP-FIG) in 2019. It provides a comprehensive set of rules for writing PHP code with a consistent style across projects and is intended to be used alongside PSR-1 Basic Coding Standard and PSR-2 Coding Style Guide. PSR-12 supersedes PSR-2 and reflects modern PHP practices while remaining compatible with established PSR-1 conventions.

PSR-12 expands PSR-2 by embracing features introduced in newer PHP versions, including type declarations, namespace usage, and contemporary syntax forms. It aims to unify coding style for new PHP codebases while allowing existing PSR-2 code to gradually adapt. The standard covers a wide range of topics relevant to everyday PHP development, from file layout and namespace and use statement organization to class structure, method declarations, and property typing.

Key areas addressed by PSR-12 include file structure and ordering of declarations, spacing and indentation, control structure formatting, visibility and type declarations for properties and methods, naming conventions, and documentation practices. It also provides guidance related to autoloading compatibility and code annotations, such as PHPDoc blocks, to improve readability and tooling support.

Adoption and tooling: there is no runtime enforcement of PSR-12, but projects commonly use static analyzers and linters, such as PHP_CodeSniffer, configured with a PSR-12 ruleset to enforce conformance. The standard is widely used by modern PHP projects and frameworks to promote consistency across packages, and it is maintained by the PHP-FIG with periodic updates to reflect evolving language features. See also PSR-1 and PSR-2 for related standards.