def _make_backend(self, name, config):
# Load the backend class
try:
backend_class = import_string(self.configs[name]["BACKEND"])
except KeyError:
raise InvalidChannelLayerError("No BACKEND specified for %s" % name)
except ImportError:
raise InvalidChannelLayerError(
"Cannot import BACKEND %r specified for %s" % (self.configs[name]["BACKEND"], name)
)
# Initialise and pass config
return backend_class(**config)
async def group_send(self, service: str, message: dict) -> None:
"""Send message to service channel group."""
try:
await self.channel_layer.group_send(self.channel_group_name(service), message)
except AttributeError:
raise InvalidChannelLayerError(
"BACKEND is not configured or doesn't support groups")
async def send_to_group(self, group: str, message: dict) -> None:
"""Sends the given message to the given group."""
try:
await self.channel_layer.group_send(group, message)
except AttributeError:
raise InvalidChannelLayerError(
"BACKEND is not configured or doesn't support groups")
async def on_connection_close(self):
# Remove channel groups
try:
for group in self.groups:
await self.group_discard(group)
except AttributeError:
raise InvalidChannelLayerError(
"BACKEND is not configured or doesn't support groups")
super().on_connection_close()
def make_test_backend(self, name):
"""
Instantiate channel layer using its test config.
"""
try:
config = self.configs[name]["TEST_CONFIG"]
except KeyError:
raise InvalidChannelLayerError("No TEST_CONFIG specified for %s" % name)
return self._make_backend(name, config)
async def open(self, *args, **kwargs):
"""Invoked when a new WebSocket is opened."""
await super().open(*args, **kwargs)
IOLoop.current().add_callback(self.channel_receive_callback)
# Initialize channel layer
self.channel_layer = get_channel_layer()
if self.channel_layer is not None:
self.channel_name = await self.channel_layer.new_channel()
self.channel_receive = functools.partial(
self.channel_layer.receive, self.channel_name)
# Add channel groups
groups = await self.get_groups() or []
try:
for group in groups:
await self.group_add(group)
except AttributeError:
raise InvalidChannelLayerError(
"BACKEND is not configured or doesn't support groups")