Variator Bundle Laravel Package

Getting Started

Minimal Setup

1. Installation:

   composer require coshi/variator-bundle
   

   Register the bundle in config/bundles.php:

   return [
       // ...
       Coshi\VariatorBundle\CoshiVariatorBundle::class => ['all' => true],
   ];
   

2. First Use Case: Define a simple variation in config/packages/coshi_variator.yaml:

   coshi_variator:
       variations:
           random_number:
               type: int
               min: 1
               max: 100
   

   Fetch variations via the builder:

   $builder = $this->container->get('coshi.variator_bundle.builder');
   $variations = $builder->build(['random_number']);
   $randomValue = $variations['random_number'];
   

Implementation Patterns

Core Workflows

1. Service-Based Callbacks: Use service methods for dynamic values (e.g., fetching IDs from a repository):

   coshi_variator:
       variations:
           user_ids:
               type: iteratorResult
               callback: ['@user.repository', 'getActiveUserIds']
   

2. Chunked Data Fetching: Optimize large datasets with chunked: true and chunk_size:

   coshi_variator:
       variations:
           paginated_ids:
               type: iteratorResult
               callback: ['@product.repository', 'findAllIds']
               chunked: true
               chunk_size: 500
   

3. Conditional Variations: Combine with Symfony’s dependency injection to pass runtime data:

   $config = [
       'dynamic_range' => [
           'type' => 'int',
           'min' => 0,
           'max' => ['@some.service', 'getDynamicMax', ['arg1', 'arg2']],
       ],
   ];
   

Integration Tips

• Doctrine Integration: Use iteratorResult with Doctrine\ORM\QueryBuilder for seamless pagination:

  $qb = $entityManager->getRepository(User::class)->createQueryBuilder('u');
  $config = ['users' => ['type' => 'iteratorResult', 'callback' => [$qb, 'getQuery']]];
  

• Event-Driven Updates: Rebuild variations dynamically in event listeners (e.g., KernelEvents::REQUEST).

Gotchas and Tips

Pitfalls

1. Deprecated Symfony Version: The bundle was last updated in 2016 and may not support Symfony 5/6+. Test thoroughly or fork for compatibility.

2. Lazy-Loading Overhead: iteratorResult with chunked: true adds SQL overhead. Benchmark for large datasets.

3. Service Unavailability: If a callback service fails, the builder throws an exception. Handle gracefully:

   try {
       $builder->build($config);
   } catch (\Exception $e) {
       $this->logger->error('Variator failed', ['error' => $e->getMessage()]);
       // Fallback logic
   }
   

Debugging

• Configuration Validation: Use var_dump($builder->getConfig()) to verify loaded variations.

• Chunking Issues: If chunked data appears incomplete, check:

  • The repository method returns a valid IterableResult.
  • chunk_size aligns with your database’s LIMIT/OFFSET behavior.

Extension Points

1. Custom Variation Types: Extend the builder to support new types (e.g., array, float):

   // In a custom service
   $builder->addVariationType('custom', function ($config) {
       return new CustomVariation($config);
   });
   

2. Configuration Overrides: Override bundle config via environment variables (e.g., .env):

   # config/packages/coshi_variator.yaml
   coshi_variator:
       variations: '%env(resolve:VARIATOR_CONFIG)%'
   

3. Caching: Cache variations for performance (e.g., with Symfony’s cache system):

   $cache = $container->get('coshi.variator_bundle.cache');
   $variations = $cache->get('variations_key', function() use ($builder) {
       return $builder->build($config);
   });