Symfony 2 Image Upload

gistfile1.aw

/**
 * @ORM\PrePersist 
 */
public function uploadIcon() {
    // proceed with upload only if isDirty
    if (!$this->isDirty)
        return;

    // delete the old file if any
    $oldIcon = APP_ROOT .'/uploads/' . $this->iconUrl;
    if ($this->iconUrl != '' && file_exists($old)) {
        unlink($old);
    }

    // guess the extension
    $ext = $this->iconFile->guessExtension();
    if (!$ext) 
        $ext = 'png';

    // upload the icon (new name will be "proj_{id}.{ext}")
    $newIcon = sprintf('proj_%d.%s', $this->id, $ext);
    $this->iconFile->move(APP_ROOT . '/uploads/', $newIcon);

    // set icon with path to icon (relative to app root)
    $this->iconUrl = $newIcon;

    // cleanup
    unset($this->iconFile);
    $this->isDirty = false;
}

In model class ...