In Symfony2, can the validation.yml file be split into multiple files using imports?

Add these lines in load method of src/Blogger/BlogBundle/DependencyInjection/BloggerBlogExtension.php.

public function load(array $configs, ContainerBuilder $container)
{
  //...
  $yamlMappingFiles = $container->getParameter('validator.mapping.loader.yaml_files_loader.mapping_files');
  $yamlMappingFiles[] = __DIR__.'/../Resources/config/comment.yml';
  $yamlMappingFiles[] = __DIR__.'/../Resources/config/enquiry.yml';
  $container->setParameter('validator.mapping.loader.yaml_files_loader.mapping_files', $yamlMappingFiles);
}

Answer added at 2015

As of Symfony 2.7, XML and Yaml constraint files located in the Resources/config/validation sub-directory of a bundle are loaded.
Prior to 2.7, only Resources/config/validation.yml (or .xml) were loaded.

More info at:

• Github PR: [FrameworkBundle] "mappings" for validation #13878
• Symfony doc: The Basics of Validation

Symfony 2.5 broke the above solutions. See: https://stackoverflow.com/a/24210501/175753