Extra Param Converter Bundle Laravel Package

Getting Started

Minimal Setup

1. Installation:

   composer require bu/extra-param-converter-bundle dev-master
   

   Ensure SensioFrameworkExtraBundle is installed and enabled (sensio_framework_extra.request.converters: true in config).

2. Register Bundle: Add to AppKernel.php:

   new Bu\ExtraParamConverterBundle\BuExtraParamConverterBundle(),
   

3. First Use Case: Convert a GET parameter (?id=1) to an entity in a controller:

   use App\Entity\User;
   
   public function showAction(User $user) { ... }
   

   The bundle auto-resolves User from the id GET parameter.

Implementation Patterns

GET Parameter Conversion

• Simple Types: Automatically converts ?name=John to $name = "John".
• Entities: Resolves ?user=123 to User entity via find() (throws NotFoundHttpException if missing).
• Collections: Supports ?users[]=1&users[]=2 → Collection<User> (requires Doctrine\Common\Collections\Collection type-hint).

Example:

public function listAction(Collection $users) { ... } // Converts ?users[]=1&users[]=2

POST/JSON Conversion

• Form Data: Converts POST arrays to entities (e.g., User from POST['name']).
• JSON Payloads: Decodes application/json requests into objects/arrays.

  public function createAction(User $user) { ... } // $user populated from JSON POST body
  

Integration Tips

1. Custom Converters: Extend Bu\ExtraParamConverterBundle\Converter\ConverterInterface for domain-specific logic.
2. Validation: Pair with Symfony Validator for POST data:

   use Symfony\Component\Validator\Constraints as Assert;
   
   public function updateAction(
       #[Assert\Type(type: User::class)]
       User $user
   ) { ... }
   

3. Nested Objects: Works with nested JSON (e.g., POST['address'] → Address entity).

Gotchas and Tips

Pitfalls

1. Missing SensioFrameworkExtraBundle:

   • Error: No converter found for argument.
   • Fix: Ensure sensio_framework_extra.request.converters: true in config.yml.

2. Entity Not Found:

   • Throws NotFoundHttpException for missing entities (e.g., ?user=999999).
   • Debug: Check UserRepository::find() logic.

3. JSON Parsing:

   • Fails silently if Content-Type: application/json is missing.
   • Fix: Add #[ParamConverter("json")] annotation or ensure headers are set.

Debugging

• Enable Debug Mode: Symfony’s debug:router or debug:container to inspect converters.
• Log Converter Events: Override Bu\ExtraParamConverterBundle\EventListener\ParamConverterListener to log conversions.

Extension Points

1. Custom Naming Strategies: Override Bu\ExtraParamConverterBundle\Converter\GetConverter to change how parameters map to entity methods (e.g., ?username=john → findByUsername()).

2. Strip Tags: Enable HTML stripping for GET/POST via config:

   bu_extra_param_converter:
       strip_tags: true
   

3. Performance: Cache entity lookups for high-traffic endpoints (e.g., find() with @Cache in Doctrine).