public function getContainerExtension()
{
if (null === $this->extension) {
$extension = $this->createContainerExtension();
if (null !== $extension) {
if (!$extension instanceof ExtensionInterface) {
throw new \LogicException(sprintf('Extension %s must implement Symfony\Component\DependencyInjection\Extension\ExtensionInterface.', get_class($extension)));
}
// check naming convention
$basename = preg_replace('/Bundle$/', '', $this->getName());
$expectedAlias = Container::underscore($basename);
if ($expectedAlias != $extension->getAlias()) {
throw new \LogicException(sprintf(
'Users will expect the alias of the default extension of a bundle to be the underscored version of the bundle name ("%s"). You can override "Bundle::getContainerExtension()" if you want to use "%s" or another alias.',
$expectedAlias, $extension->getAlias()
));
}
$this->extension = $extension;
} else {
$this->extension = false;
}
}
if ($this->extension) {
return $this->extension;
}
}