text: import logging
  
  from django.apps import AppConfig
  from django.conf import settings
  
  from haystack import connection_router, connections
  from haystack.utils import loading
  
  
  class HaystackConfig(AppConfig):
      name = "haystack"
      signal_processor = None
      stream = None
  
      def ready(self):
          # Setup default logging.
          log = logging.getLogger("haystack")
          self.stream = logging.StreamHandler()
          self.stream.setLevel(logging.INFO)
          log.addHandler(self.stream)
  
          # Setup the signal processor.
          if not self.signal_processor:
              signal_processor_path = getattr(
                  settings,
                  "HAYSTACK_SIGNAL_PROCESSOR",
                  "haystack.signals.BaseSignalProcessor",
              )
              signal_processor_class = loading.import_class(signal_processor_path)
              self.signal_processor = signal_processor_class(
                  connections, connection_router
              )
  