Export Bundle Laravel Package

Getting Started

Minimal Setup

1. Install via Composer (if not archived, but since it is, check for forks or alternatives like league/csv + custom logic):

   composer require bluetea/export-bundle
   

   Note: Due to archival, verify compatibility with your Symfony version (likely Symfony2).

2. Enable the Bundle in app/AppKernel.php:

   new BlueTea\ExportBundle\BlueTeaExportBundle(),
   

3. Basic CSV Export Controller:

   use BlueTea\ExportBundle\Exporter\ExporterInterface;
   use BlueTea\ExportBundle\Exporter\CsvExporter;
   
   class ExportController extends Controller
   {
       public function exportAction()
       {
           $exporter = $this->get('blue_tea_export.exporter.csv');
           $data = $this->getDoctrine()->getRepository('AppBundle:User')->findAll();
   
           return $exporter->export($data, 'users.csv');
       }
   }
   

4. Route the Controller:

   # app/config/routing.yml
   export_users:
       path:     /export/users
       defaults: { _controller: AppBundle:Export:export }
   

First Use Case

Export a Doctrine entity (e.g., User) to CSV with headers:

$exporter = $this->get('blue_tea_export.exporter.csv');
$users = $this->getDoctrine()->getRepository('AppBundle:User')->findAll();
$headers = ['ID', 'Email', 'Name']; // Map to entity properties

return $exporter->export($users, 'users.csv', $headers);

Implementation Patterns

Core Workflow

1. Dependency Injection: Inject ExporterInterface (or CsvExporter directly) into services/controllers:

   public function __construct(ExporterInterface $exporter) {
       $this->exporter = $exporter;
   }
   

2. Data Transformation: Use factories to format data before export. Example for custom objects:

   $factory = new \BlueTea\ExportBundle\Factory\ArrayFactory();
   $formattedData = $factory->transform($users); // Converts entities to arrays
   $this->exporter->export($formattedData, 'output.csv');
   

3. Streaming Large Datasets: For memory efficiency, stream rows instead of loading all data:

   $query = $this->getDoctrine()->getRepository('AppBundle:User')->createQueryBuilder('u');
   $exporter->setStreamingMode(true);
   $exporter->export($query->getResult(), 'large_users.csv');
   

4. Dynamic Headers: Auto-generate headers from Doctrine metadata:

   $metadata = $this->getDoctrine()->getManager()->getMetadataFactory()->getMetadataFor('AppBundle:User');
   $headers = array_map(function($field) { return $field->getName(); }, $metadata->getFieldNames());
   

Integration Tips

• Symfony Forms: Attach exports to form actions:

  $form = $this->createFormBuilder()
      ->add('export', SubmitType::class, ['label' => 'Export CSV'])
      ->getForm();
  
  if ($form->isSubmitted() && $form->isValid()) {
      return $this->exportAction();
  }
  

• Event Listeners: Trigger exports on entity lifecycle events (e.g., post-save):

  $eventManager->addEventListener(
      KernelEvents::TERMINATE,
      function () use ($exporter) {
          $exporter->export($data, 'audit.csv');
      }
  );
  

• Custom Exporters: Extend AbstractExporter to support new formats (e.g., JSON):

  class JsonExporter extends AbstractExporter
  {
      protected function writeHeader(array $headers) { /* ... */ }
      protected function writeRow(array $row) { /* ... */ }
  }
  

Gotchas and Tips

Pitfalls

1. Archived Status:

   • The bundle is unmaintained (last release: 2014). Test thoroughly or fork for updates.
   • Alternative: Use league/csv or matthiasnoback/symfony-export-bundle for modern Symfony.

2. Doctrine Dependency:

   • Assumes Doctrine ORM. For non-Doctrine projects, mock repositories or use raw arrays.

3. Memory Limits:

   • Large datasets may hit PHP memory limits. Use setStreamingMode(true) or chunk queries:

     $exporter->export(array_chunk($users, 1000), 'chunked_users.csv');
     

4. Header Mismatch:

   • Headers must match data array keys. Use array_keys($data[0]) for auto-detection:

     $headers = array_keys(reset($users));
     

5. Encoding Issues:

   • CSV may corrupt non-UTF-8 data. Force encoding:

     $exporter->setEncoding('UTF-8');
     

Debugging

• Empty Output: Verify:
  • Data is not empty (count($data) > 0).
  • Headers match data structure.
  • No exceptions in writeRow() (check logs).
• Permissions: Ensure web server can write to the output path (e.g., var/exports/).

Extension Points

1. Custom Factories: Override ArrayFactory to transform complex objects:

   class UserFactory extends ArrayFactory
   {
       public function transform($user)
       {
           return [
               'id' => $user->getId(),
               'full_name' => $user->getFirstName() . ' ' . $user->getLastName(),
           ];
       }
   }
   

2. Post-Export Actions: Hook into postExport event (if supported) or chain services:

   $exporter->export($data, 'file.csv');
   $this->mailer->send('export@ready@example.com', 'Export ready', ['file' => 'file.csv']);
   

3. Configuration: Override defaults in config.yml:

   blue_tea_export:
       csv:
           delimiter: ';'
           enclosure: '"'
           escape_char: '\\'
           line_ending: "\r\n"
           include_headers: true
   

Pro Tips

• Cache Exports: Store generated files in cache/ and clear on data changes.
• Security: Validate user permissions before allowing exports:

  $this->denyAccessUnlessGranted('ROLE_EXPORT', $user);
  

• Testing: Mock ExporterInterface in PHPUnit:

  $mockExporter = $this->createMock(ExporterInterface::class);
  $mockExporter->expects($this->once())->method('export');
  $this->controller->setExporter($mockExporter);