dsDynamicCredentialsFilter.class.php

<?php
/**
 * dsDynamicCredentialsFilter
 *
 * This filter is created to add some credentials to user dynamically.
 *
 * It does following things:
 * 
 * 1. retrieves current route,
 * 2. checks whether it is sfObjectRoute
 * 3. retrieves an object inside of that sfObjectRoute
 * 4. calls $object->getAddedCredentialsNames($user) where $user is instance of myUser
 * 5. adds credentials returned by #4 to $user
 *
 * @author Andrei Dziahel <[email protected]>
 */
class dsDynamicCredentialsFilter extends sfFilter
{
  public function execute($filterChain)
  {
    if ($this->isFirstCall())
    {
      $context = $this->getContext();

      /* @var $user sfGuardSecurityUser */
      $user = $context->getUser(); //TODO: fix hardcoded user instance
      $routename = $context->getRouting()->getCurrentRouteName();
      $routes = $context->getRouting()->getRoutes();
      
      /* @var $route sfObjectRoute */
      $route = $routes[$routename];

      if ($route instanceof sfObjectRoute && $route->isBound())
      {
        $object = false;
        try
        {
          $object = $route->getObject();
        }
        catch (LogicException $e)
        {
          $object = false;
        }

        if (false !== $object && method_exists($object, 'getAddedCredentialsNames')) 
        {
          $names = call_user_func(array($object, 'getAddedCredentialsNames'), $user); //TODO: fix hardcoded method name
          $user->addCredentials($names);
        }
        else
        {
          if (sfConfig::get('sf_logging_enabled'))
          {
            $context->getEventDispatcher()->notify(new sfEvent($this,
                'application.log',
                array('Can\'t retrieve object for route "'.$routename.'", skipping')));
          }
        }
      }
    }

    $filterChain->execute();
  }
}

Post.class.php

<?php
class Post extends BasePost
{
  public function getAddedCredentialsNames(sfGuardSecurityUser $user)
  {
    if ($this->get('owner_id') == $user->getProfile()->getId())
    {
      return 'post_edit';
    }
  }
}