Web Profiler Bundle Laravel Package

Getting Started

Minimal Setup

1. Installation:

   composer require symfony/web-profiler-bundle
   

   Add to config/bundles.php (Symfony 5+):

   return [
       // ...
       Symfony\WebProfilerBundle\WebProfilerBundle::class => ['dev' => true, 'test' => true],
   ];
   

2. Enable Debug Mode: Set APP_DEBUG=true in .env (or config/packages/dev.php for Symfony 5+):

   APP_DEBUG=1
   APP_ENV=dev
   

3. First Use Case:

   • Trigger a request (e.g., visit / or run php bin/console server:run).
   • Observe the Debug Toolbar at the bottom of the page, showing:
     • Request time, memory usage, and HTTP status.
     • Click the toolbar to open the Profiler (/_profiler/).
   • Inspect default panels like Requests, Time, Router, and Doctrine (if using DBAL/ORM).

Implementation Patterns

Core Workflows

1. Debugging Requests:

   • Use the Requests panel to compare current vs. previous requests (e.g., after refactoring).
   • Filter by URL, method, or status code to isolate issues.

2. Performance Profiling:

   • Timeline panel visualizes execution flow (e.g., controller → service → DB calls).
   • Sort by duration to identify slow components (e.g., N+1 queries, heavy services).
   • Example: Click a DB query in Doctrine to see its SQL and execution time.

3. State Inspection:

   • Response panel: Inspect headers, cookies, or rendered content (e.g., debug API responses).
   • Exceptions panel: Review uncaught errors with stack traces and context.

4. Custom Data Collection:

   • Create a DataCollector to log custom metrics (e.g., third-party API calls):

     // src/Collector/MyCustomCollector.php
     use Symfony\Component\HttpKernel\DataCollector\DataCollector;
     
     class MyCustomCollector extends DataCollector {
         public function collect(Request $request, Response $response, \Throwable $exception = null) {
             $this->data['api_calls'] = $this->trackApiCalls();
             return $this->data;
         }
     
         public function getName() { return 'my_custom'; }
     }
     

   • Register in config/packages/dev.php:

     framework:
         profiler:
             collectors:
                 my_custom: App\Collector\MyCustomCollector
     

5. Integration with Tests:

   • Use Profiler::enable() in PHPUnit tests to capture profiler data:

     use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
     
     class MyTest extends WebTestCase {
         public function testSomething() {
             $client = static::createClient();
             $client->request('GET', '/');
             $profiler = static::getContainer()->get('profiler');
             $profiler->collect($client->getInternalRequest(), $client->getInternalResponse());
             // Assertions using profiler data...
         }
     }
     

Gotchas and Tips

Pitfalls

1. Debug Toolbar Not Showing:

   • Ensure APP_DEBUG=1 and APP_ENV=dev.
   • Clear cache: php bin/console cache:clear.
   • Check for middleware blocking the toolbar (e.g., CORS or security middleware). Exclude /_profiler/* in production.

2. Performance Overhead:

   • The profiler adds ~10-20% overhead in development. Disable in CI/staging:

     APP_DEBUG=0
     

   • Use --env=test for tests to avoid profiler noise.

3. Doctrine Queries Missing:

   • Ensure doctrine:dbal or doctrine:orm is installed and configured.
   • For custom repositories, enable SQL logging in config/packages/dev/dbal.php:

     dbal:
         logging: true
     

4. Collector Conflicts:

   • Avoid naming custom collectors after built-in ones (e.g., time, router).
   • Clear cache after adding new collectors.

Debugging Tips

1. Inspecting Twig Rendering:

   • Use the Twig panel to see template hierarchy and timing for each block.
   • Click a template to debug variable dumps.

2. Event Dispatcher Debugging:

   • The Events panel lists all dispatched events with their listeners and execution order.
   • Useful for debugging middleware or event subscriber issues.

3. Memory Leaks:

   • Monitor the Memory panel across requests to spot growing memory usage.
   • Compare with memory_get_usage() in PHP for granular tracking.

4. Custom Data Visualization:

   • Extend the profiler UI by overriding templates in templates/bundles/webprofiler/ (Symfony 4+).
   • Example: Add a chart for your custom collector’s data using Twig.

Configuration Quirks

1. Disabling Specific Collectors:

   # config/packages/dev/profiler.yaml
   framework:
       profiler:
           enabled: true
           collectors:
               'Symfony\Bundle\WebServerBundle\DataCollector\WebServerCollector': false
   

2. Profiler in Subrequests:

   • The profiler works for subrequests (e.g., from Renderer or HttpClient), but data is scoped to the parent request.
   • Use Profiler::enable() explicitly for isolated subrequests.

3. Production-Like Debugging:

   • Use APP_ENV=prod with APP_DEBUG=1 to test production configurations without toolbar noise.
   • Access profiler via /_profiler/ (disable in firewalls if needed):

     security:
         firewalls:
             dev:
                 pattern: ^/(_(profiler|wdt)|css|images|js)/
                 security: false