Handling MySQL errors from Symfony application

I wish to know what is the best method to handle MySQL exceptions from a Symfony application, less said for example this one from normal enviroment(not dev):

Oops! An Error Occurred The server returned a "500 Internal Server Error".

which translate at _dev as follow:

SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '343434' for key 'rut'

how do yours handle with this kind of errors in order to show a message to end users or something more friendly?

Solution

Your best bet is to make a custom error page, and optionally create a custom error handler to alert you of the error.

First, create a custom error page, just create a file in /path/to/project/config/error/error.html.php. Symfony will automatically use your error page instead of its own if it exists.

If you want to get a bit more advanced, you can add an event listener to handle uncaught exceptions. To do this, edit /path/to/project/config/ProjectConfiguration.class.php and add a listener like so:

class ProjectConfiguration extends sfProjectConfiguration
{
  public function setup()
  {
    //...
    $this->dispatcher->connect('application.throw_exception', array($this, 'listenToException'));
  }

  public function listenToException(sfEvent $event)
  {
    $handler = new myExceptionHandler($event);
    $handler->doSomethingHere();
  }
}

Then, all you have to do is create your own myExceptionHandler class that excepts an sfEvent $event parameter. You can do whatever you want in here, I prefer to send an email to myself to tell me that an error has occurred.

Here is a brief example:

class myExceptionHandler
{
  protected $event;

  public function __construct(sfEvent $event)
  {
    $this->event = $event;
  }

  protected function getMailer()
  {
    return sfContext::getInstance()->getMailer();
  }

  public function notify()
  {
    $subject = 'Uncaught Exception';
    $body = $this->event->getSubject();

    $mailer = $this->getMailer();
    $mailer->composeAndSend('root@yourserver.com', 'you@youremail.com', $subject, $body);
  }
}

In this example, you would just call $handler->notify() from your project configuration and it would email you the stack trace. You could also include other information like $_SERVER variables etc...