No-op implementation of a Url Generator, needed for backward compatibility.
Expanded class hierarchy of NullGenerator
class NullGenerator extends UrlGenerator {
  /**
   * Override the parent constructor.
   */
  public function __construct() {
  }
  /**
   * Overrides Drupal\Core\Routing\UrlGenerator::generate();
   */
  public function generate($name, $parameters = array(), $absolute = FALSE) {
    throw new RouteNotFoundException();
  }
  /**
   * Overrides Drupal\Core\Routing\UrlGenerator::setContext();
   */
  public function setContext(RequestContext $context) {
  }
  /**
   * Implements Symfony\Component\Routing\RequestContextAwareInterface::getContext();
   */
  public function getContext() {
  }
  /**
   * Overrides Drupal\Core\Routing\UrlGenerator::processPath().
   */
  protected function processPath($path, &$options = array()) {
    return $path;
  }
}| Name   | Modifiers | Type | Description | Overrides | 
|---|---|---|---|---|
| NullGenerator:: | public | function | Overrides Drupal\Core\Routing\UrlGenerator::generate(); Overrides UrlGenerator:: | |
| NullGenerator:: | public | function | Implements Symfony\Component\Routing\RequestContextAwareInterface::getContext(); Overrides UrlGenerator:: | |
| NullGenerator:: | protected | function | Overrides Drupal\Core\Routing\UrlGenerator::processPath(). Overrides UrlGenerator:: | |
| NullGenerator:: | public | function | Overrides Drupal\Core\Routing\UrlGenerator::setContext(); Overrides UrlGenerator:: | |
| NullGenerator:: | public | function | Override the parent constructor. Overrides UrlGenerator:: | |
| ProviderBasedGenerator:: | protected | property | The route provider for this generator. | |
| ProviderBasedGenerator:: | public | function | Convert a route identifier (name, content object etc) into a string
usable for logging and other debug/error messages Overrides VersatileGeneratorInterface:: | 1 | 
| ProviderBasedGenerator:: | public | function | Support a route object and any string as route name Overrides VersatileGeneratorInterface:: | 1 | 
| UrlGenerator:: | protected | property | The base path to use for urls. | |
| UrlGenerator:: | protected | property | The base url to use for urls. | |
| UrlGenerator:: | protected | property | ||
| UrlGenerator:: | protected | property | This array defines the characters (besides alphanumeric ones) that will not be percent-encoded in the path segment of the generated URL. | |
| UrlGenerator:: | protected | property | ||
| UrlGenerator:: | protected | property | Whether both secure and insecure session cookies can be used simultaneously. | |
| UrlGenerator:: | protected | property | The path processor to convert the system path to one suitable for urls. | |
| UrlGenerator:: | protected | property | A request object. | |
| UrlGenerator:: | protected | property | ||
| UrlGenerator:: | protected | property | The script path to use for urls. | |
| UrlGenerator:: | protected | property | ||
| UrlGenerator:: | protected | function | 2 | |
| UrlGenerator:: | public | function | Implements \Drupal\Core\Routing\PathBasedGeneratorInterface::generateFromPath(). Overrides PathBasedGeneratorInterface:: | |
| UrlGenerator:: | public static | function | Returns the target path as relative reference from the base path. | |
| UrlGenerator:: | public | function | Parses an array into a valid, rawurlencoded query string. | |
| UrlGenerator:: | protected | function | Returns whether or not the url generator has been initialized. | |
| UrlGenerator:: | public | function | Returns whether to throw an exception on incorrect parameters.
Null means the requirements check is deactivated completely. Overrides ConfigurableRequirementsInterface:: | |
| UrlGenerator:: | public | function | Implements \Drupal\Core\Routing\PathBasedGeneratorInterface::setBasePath(). Overrides PathBasedGeneratorInterface:: | |
| UrlGenerator:: | public | function | Implements \Drupal\Core\Routing\PathBasedGeneratorInterface::setBaseUrl(). Overrides PathBasedGeneratorInterface:: | |
| UrlGenerator:: | public | function | Implements \Drupal\Core\Routing\PathBasedGeneratorInterface::setRequest(). Overrides PathBasedGeneratorInterface:: | |
| UrlGenerator:: | public | function | Implements \Drupal\Core\Routing\PathBasedGeneratorInterface::setScriptPath(). Overrides PathBasedGeneratorInterface:: | |
| UrlGenerator:: | public | function | Enables or disables the exception on incorrect parameters.
Passing null will deactivate the requirements check completely. Overrides ConfigurableRequirementsInterface:: | |
| UrlGeneratorInterface:: | constant | Generates an absolute path, e.g. "/dir/file". | ||
| UrlGeneratorInterface:: | constant | Generates an absolute URL, e.g. "http://example.com/dir/file". | ||
| UrlGeneratorInterface:: | constant | Generates a network path, e.g. "//example.com/dir/file". Such reference reuses the current scheme but specifies the host. | ||
| UrlGeneratorInterface:: | constant | Generates a relative path based on the current request path, e.g. "../parent-file". |