Symfony 7.4 Drops XML Config: What Developers Need to Know

New Feature: XML Configuration Deprecated

Symfony, the leading PHP framework, will deprecate XML configuration in the upcoming Symfony 7.4 release (scheduled for November 2025) and remove it entirely in Symfony 8.0, encouraging developers to adopt YAML or PHP‑based configs.

Since its early versions Symfony has supported three configuration formats— PHP 、 YAML 、 XML. All are compiled to PHP at runtime, so performance differences are negligible. XML usage has been declining, and recent releases disable it by default; re‑enabling requires editing src/Kernel.php and overriding configureContainer() and configureRoutes().

YAML Configuration Gets Auto‑Completion Upgrade

YAML remains the preferred format. Symfony 7.4 introduces JSON‑Schema definitions for services and routes, allowing IDEs such as PhpStorm to provide real‑time validation and auto‑completion. The new schema is declared at the top of each YAML file with a $schema: line.

# config/services.yaml
# $schema: ../vendor/symfony/dependency-injection/Loader/schema/services.schema.json

parameters:
  # ...

services:
  # ...

# config/routes.yaml
# $schema: ../vendor/symfony/routing/Loader/schema/routing.schema.json

controllers:
  # ...

The improvement also extends to validation and serialization metadata, helping developers avoid configuration errors and boost productivity.

PHP Configuration Introduces “Array Shapes”

For developers who prefer pure‑code configuration, Symfony 7.4 adds “array shapes”, a feature that lets PHP config files mimic the readability of YAML while retaining type safety.

// config/routes.php
return [
    'route1_name' => ['path' => '/path1'],
    'when@dev'   => [
        'route2_name' => ['path' => '/path2'],
    ],
];

// config/services.php
return [
    'parameters' => [
        'foo' => 'bar',
    ],
    'services' => [
        '_defaults' => [
            'public' => true,
        ],
        Bar::class => null,
        'my_service' => [
            'class' => Bar::class,
            'arguments' => ['%foo%'],
        ],
    ],
];

These array shapes integrate tightly with static analysis tools and IDEs, delivering rich code hints and auto‑completion. The actual experience depends on the developer’s editor.