Karma Bundle Laravel Package

Getting Started

Minimal Setup Steps

1. Prerequisites

   • Install CCDNForumForumBundle first (this bundle depends on it).
   • Ensure Symfony 2.0.x and PHP 5.3.6+ are installed.
   • Add ccdn-forum/karma-bundle to composer.json:

     composer require ccdn-forum/karma-bundle
     

2. Bundle Registration Add to app/AppKernel.php:

   new CCDN\ForumBundle\KarmaBundle(),
   

3. Database Migrations Run Doctrine migrations (if included in the bundle) or manually create the karma table:

   CREATE TABLE karma (
       id INT AUTO_INCREMENT PRIMARY KEY,
       post_id INT NOT NULL,
       user_id INT NOT NULL,
       rating TINYINT NOT NULL, -- +1 or -1
       comment TEXT,
       created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
       FOREIGN KEY (post_id) REFERENCES forum_posts(id),
       FOREIGN KEY (user_id) REFERENCES users(id)
   );
   

4. First Use Case Display a "Rate Post" button in your forum template:

   {% if is_granted('ROLE_USER') %}
       {{ path('ccdn_forum_karma_rate', { postId: post.id }) }}
   {% endif %}
   

Implementation Patterns

Core Workflows

1. Rating a Post

   • Use the POST route /forum/karma/rate/{postId} with form data:

     // Controller action (example)
     public function rateAction(Request $request, $postId) {
         $rating = $request->request->get('rating'); // +1 or -1
         $comment = $request->request->get('comment');
         $this->get('ccdn_forum.karma.manager')->ratePost($postId, $rating, $comment);
         return new RedirectResponse($request->headers->get('referer'));
     }
     

2. Displaying Karma

   • Fetch karma for a post in a Twig template:

     {% set karma = karma(post) %}
     <div class="karma-score">
         {{ karma.score }}  -- {{ karma.votes }} votes
     </div>
     

3. Integration with ForumBundle

   • Extend ForumPost entity to include karma methods:

     // In your ForumPost entity
     public function getKarmaScore() {
         return $this->getKarmaManager()->getPostScore($this->id);
     }
     

Common Patterns

• Form Handling Use the bundle’s built-in form type (CCDN\ForumBundle\KarmaBundle\Form\Type\KarmaType) for rating forms:

  $form = $this->createForm(KarmaType::class, $post, [
      'action' => $this->generateUrl('ccdn_forum_karma_rate', ['postId' => $post->id])
  ]);
  

• Event Listeners Trigger actions post-rating via events (e.g., update user reputation):

  // In services.yml
  ccdn_forum.karma.listener:
      class: AppBundle\EventListener\KarmaListener
      tags:
          - { name: kernel.event_listener, event: ccdn_forum.karma.rated, method: onKarmaRated }
  

• API Access Expose karma data via API (e.g., FOSRestBundle):

  # config_routing.yml
  ccdn_forum_karma_api:
      path: /api/forum/post/{id}/karma
      defaults: { _controller: CCDN\ForumBundle\KarmaBundle\Controller\ApiController::getKarma }
  

Gotchas and Tips

Pitfalls

1. Missing Dependencies

   • Error: Class 'CCDN\ForumBundle\ForumBundle' not found.
   • Fix: Ensure CCDNForumForumBundle is installed and registered before KarmaBundle.

2. Database Schema Mismatch

   • Error: Column 'rating' not found or Foreign key constraint fails.
   • Fix: Manually verify the karma table structure matches the bundle’s expectations (see Getting Started).

3. Permission Issues

   • Error: Users can rate posts without checks.
   • Fix: Implement custom voters or extend the bundle’s security logic:

     // src/Acme/ForumBundle/Security/Voter/KarmaVoter.php
     public function supportsAttribute($attribute) {
         return $attribute === 'rate_post';
     }
     

4. Bootstrap CSS/JS Conflicts

   • Error: Styling breaks if Bootstrap is loaded twice.
   • Fix: Exclude default Bootstrap assets if already included:

     {% block stylesheets %}
         {{ parent() }}
         {% if not app.hasBootstrap %}
             {{ asset('bundles/ccdnforum/css/bootstrap.css') }}
         {% endif %}
     {% endblock %}
     

Debugging Tips

• Enable Doctrine Logging Add to config.yml to debug queries:

  doctrine:
      dbal:
          logging: true
  

• Check Event Dispatching Verify events fire by subscribing a debug listener:

  public function onKarmaRated(KarmaEvent $event) {
      error_log("Karma rated: " . print_r($event->getData(), true));
  }
  

Extension Points

1. Custom Rating Logic Override the rating manager:

   # services.yml
   ccdn_forum.karma.manager:
       class: AppBundle\Service\CustomKarmaManager
       parent: ccdn_forum.karma.manager
   

2. Add Rating Categories Extend the Karma entity to support multiple rating types (e.g., "helpfulness," "clarity"):

   // src/AppBundle/Entity/Karma.php
   class Karma extends CCDN\ForumBundle\KarmaBundle\Entity\Karma {
       private $category;
   }
   

3. Localization Translate rating labels (e.g., "Upvote," "Downvote") by overriding Twig templates:

   {# templates/CCDNForumKarmaBundle/Karma/rate.html.twig #}
   {% trans %}Upvote{% endtrans %}
   

4. Rate Limiting Prevent spam by adding a rate-limit service:

   public function canRate($userId, $postId) {
       $lastRating = $this->em->getRepository('CCDNForumKarmaBundle:Karma')
           ->findBy(['user_id' => $userId, 'post_id' => $postId], ['created_at' => 'DESC']);
       return !$lastRating || (time() - $lastRating[0]->getCreatedAt()->getTimestamp() > 86400); // 24h cooldown
   }