This PR was squashed before being merged into the 4.1 branch (closes #27128). Discussion ---------- [Messenger] Middleware factories support in config | Q | A | ------------- | --- | Branch? | master  | Bug fix? | no | New feature? | yes  | BC breaks? | no  | Deprecations? | no  | Tests pass? | yes  | Fixed tickets | N/A  | License | MIT | Doc PR | todo Following #26864, this would allow to configure easily the middlewares by using an abstract factory definition to which are provided simple arguments (just scalars, no services references). For instance, here is how the DoctrineBundle would benefit from such a feature (also solving the wiring of the `DoctrineTransactionMiddleware` reverted in #26684): ```yaml framework: messenger: buses: default: middleware: - logger - doctrine_transaction_middleware: ['entity_manager_name'] ``` where `doctrine_transaction_middleware` would be an abstract factory definition provided by the doctrine bundle: ```yml services: doctrine.orm.messenger.middleware_factory.transaction: class: Symfony\Bridge\Doctrine\Messenger\DoctrineTransactionMiddlewareFactory arguments: ['@doctrine'] doctrine_transaction_middleware: class: Symfony\Bridge\Doctrine\Messenger\DoctrineTransactionMiddleware factory: ['@doctrine.orm.messenger.middleware_factory.transaction', 'createMiddleware'] abstract: true # the default arguments to use when none provided from config. # i.e: # middlewares: # - doctrine_transaction_middleware: ~ arguments: ['default'] ``` and is interpreted as: ```yml buses: default: middleware: - id: logger arguments: { } - id: doctrine_transaction_middleware arguments: - entity_manager_name default_middleware: true ``` --- <details> <summary>Here is the whole config reference with these changes: </summary> ```yaml # Messenger configuration messenger: enabled: true routing: # Prototype message_class: senders: [] serializer: enabled: true format: json context: # Prototype name: ~ encoder: messenger.transport.serializer decoder: messenger.transport.serializer adapters: # Prototype name: dsn: ~ options: [] default_bus: null buses: # Prototype name: default_middleware: true middleware: # Prototype - id: ~ # Required arguments: [] ``` </details> Commits ------- f5ef421 [Messenger] Middleware factories support in config

Uh oh!