bazarr/libs/flask_socketio/__init__.py

1007 lines
47 KiB
Python

from functools import wraps
import os
import sys
# make sure gevent-socketio is not installed, as it conflicts with
# python-socketio
gevent_socketio_found = True
try:
from socketio import socketio_manage # noqa: F401
except ImportError:
gevent_socketio_found = False
if gevent_socketio_found:
print('The gevent-socketio package is incompatible with this version of '
'the Flask-SocketIO extension. Please uninstall it, and then '
'install the latest version of python-socketio in its place.')
sys.exit(1)
import flask
from flask import _request_ctx_stack, has_request_context, json as flask_json
from flask.sessions import SessionMixin
import socketio
from socketio.exceptions import ConnectionRefusedError # noqa: F401
from werkzeug.debug import DebuggedApplication
from werkzeug._reloader import run_with_reloader
from .namespace import Namespace
from .test_client import SocketIOTestClient
class _SocketIOMiddleware(socketio.WSGIApp):
"""This WSGI middleware simply exposes the Flask application in the WSGI
environment before executing the request.
"""
def __init__(self, socketio_app, flask_app, socketio_path='socket.io'):
self.flask_app = flask_app
super(_SocketIOMiddleware, self).__init__(socketio_app,
flask_app.wsgi_app,
socketio_path=socketio_path)
def __call__(self, environ, start_response):
environ = environ.copy()
environ['flask.app'] = self.flask_app
return super(_SocketIOMiddleware, self).__call__(environ,
start_response)
class _ManagedSession(dict, SessionMixin):
"""This class is used for user sessions that are managed by
Flask-SocketIO. It is simple dict, expanded with the Flask session
attributes."""
pass
class SocketIO(object):
"""Create a Flask-SocketIO server.
:param app: The flask application instance. If the application instance
isn't known at the time this class is instantiated, then call
``socketio.init_app(app)`` once the application instance is
available.
:param manage_session: If set to ``True``, this extension manages the user
session for Socket.IO events. If set to ``False``,
Flask's own session management is used. When using
Flask's cookie based sessions it is recommended that
you leave this set to the default of ``True``. When
using server-side sessions, a ``False`` setting
enables sharing the user session between HTTP routes
and Socket.IO events.
:param message_queue: A connection URL for a message queue service the
server can use for multi-process communication. A
message queue is not required when using a single
server process.
:param channel: The channel name, when using a message queue. If a channel
isn't specified, a default channel will be used. If
multiple clusters of SocketIO processes need to use the
same message queue without interfering with each other,
then each cluster should use a different channel.
:param path: The path where the Socket.IO server is exposed. Defaults to
``'socket.io'``. Leave this as is unless you know what you are
doing.
:param resource: Alias to ``path``.
:param kwargs: Socket.IO and Engine.IO server options.
The Socket.IO server options are detailed below:
:param client_manager: The client manager instance that will manage the
client list. When this is omitted, the client list
is stored in an in-memory structure, so the use of
multiple connected servers is not possible. In most
cases, this argument does not need to be set
explicitly.
:param logger: To enable logging set to ``True`` or pass a logger object to
use. To disable logging set to ``False``. The default is
``False``. Note that fatal errors will be logged even when
``logger`` is ``False``.
:param json: An alternative json module to use for encoding and decoding
packets. Custom json modules must have ``dumps`` and ``loads``
functions that are compatible with the standard library
versions. To use the same json encoder and decoder as a Flask
application, use ``flask.json``.
:param async_handlers: If set to ``True``, event handlers for a client are
executed in separate threads. To run handlers for a
client synchronously, set to ``False``. The default
is ``True``.
:param always_connect: When set to ``False``, new connections are
provisory until the connect handler returns
something other than ``False``, at which point they
are accepted. When set to ``True``, connections are
immediately accepted, and then if the connect
handler returns ``False`` a disconnect is issued.
Set to ``True`` if you need to emit events from the
connect handler and your client is confused when it
receives events before the connection acceptance.
In any other case use the default of ``False``.
The Engine.IO server configuration supports the following settings:
:param async_mode: The asynchronous model to use. See the Deployment
section in the documentation for a description of the
available options. Valid async modes are ``threading``,
``eventlet``, ``gevent`` and ``gevent_uwsgi``. If this
argument is not given, ``eventlet`` is tried first, then
``gevent_uwsgi``, then ``gevent``, and finally
``threading``. The first async mode that has all its
dependencies installed is then one that is chosen.
:param ping_interval: The interval in seconds at which the server pings
the client. The default is 25 seconds. For advanced
control, a two element tuple can be given, where
the first number is the ping interval and the second
is a grace period added by the server.
:param ping_timeout: The time in seconds that the client waits for the
server to respond before disconnecting. The default
is 5 seconds.
:param max_http_buffer_size: The maximum size of a message when using the
polling transport. The default is 1,000,000
bytes.
:param allow_upgrades: Whether to allow transport upgrades or not. The
default is ``True``.
:param http_compression: Whether to compress packages when using the
polling transport. The default is ``True``.
:param compression_threshold: Only compress messages when their byte size
is greater than this value. The default is
1024 bytes.
:param cookie: If set to a string, it is the name of the HTTP cookie the
server sends back to the client containing the client
session id. If set to a dictionary, the ``'name'`` key
contains the cookie name and other keys define cookie
attributes, where the value of each attribute can be a
string, a callable with no arguments, or a boolean. If set
to ``None`` (the default), a cookie is not sent to the
client.
:param cors_allowed_origins: Origin or list of origins that are allowed to
connect to this server. Only the same origin
is allowed by default. Set this argument to
``'*'`` to allow all origins, or to ``[]`` to
disable CORS handling.
:param cors_credentials: Whether credentials (cookies, authentication) are
allowed in requests to this server. The default is
``True``.
:param monitor_clients: If set to ``True``, a background task will ensure
inactive clients are closed. Set to ``False`` to
disable the monitoring task (not recommended). The
default is ``True``.
:param engineio_logger: To enable Engine.IO logging set to ``True`` or pass
a logger object to use. To disable logging set to
``False``. The default is ``False``. Note that
fatal errors are logged even when
``engineio_logger`` is ``False``.
"""
def __init__(self, app=None, **kwargs):
self.server = None
self.server_options = {}
self.wsgi_server = None
self.handlers = []
self.namespace_handlers = []
self.exception_handlers = {}
self.default_exception_handler = None
self.manage_session = True
# We can call init_app when:
# - we were given the Flask app instance (standard initialization)
# - we were not given the app, but we were given a message_queue
# (standard initialization for auxiliary process)
# In all other cases we collect the arguments and assume the client
# will call init_app from an app factory function.
if app is not None or 'message_queue' in kwargs:
self.init_app(app, **kwargs)
else:
self.server_options.update(kwargs)
def init_app(self, app, **kwargs):
if app is not None:
if not hasattr(app, 'extensions'):
app.extensions = {} # pragma: no cover
app.extensions['socketio'] = self
self.server_options.update(kwargs)
self.manage_session = self.server_options.pop('manage_session',
self.manage_session)
if 'client_manager' not in self.server_options:
url = self.server_options.pop('message_queue', None)
channel = self.server_options.pop('channel', 'flask-socketio')
write_only = app is None
if url:
if url.startswith(('redis://', "rediss://")):
queue_class = socketio.RedisManager
elif url.startswith(('kafka://')):
queue_class = socketio.KafkaManager
elif url.startswith('zmq'):
queue_class = socketio.ZmqManager
else:
queue_class = socketio.KombuManager
queue = queue_class(url, channel=channel,
write_only=write_only)
self.server_options['client_manager'] = queue
if 'json' in self.server_options and \
self.server_options['json'] == flask_json:
# flask's json module is tricky to use because its output
# changes when it is invoked inside or outside the app context
# so here to prevent any ambiguities we replace it with wrappers
# that ensure that the app context is always present
class FlaskSafeJSON(object):
@staticmethod
def dumps(*args, **kwargs):
with app.app_context():
return flask_json.dumps(*args, **kwargs)
@staticmethod
def loads(*args, **kwargs):
with app.app_context():
return flask_json.loads(*args, **kwargs)
self.server_options['json'] = FlaskSafeJSON
resource = self.server_options.pop('path', None) or \
self.server_options.pop('resource', None) or 'socket.io'
if resource.startswith('/'):
resource = resource[1:]
if os.environ.get('FLASK_RUN_FROM_CLI'):
if self.server_options.get('async_mode') is None:
self.server_options['async_mode'] = 'threading'
self.server = socketio.Server(**self.server_options)
self.async_mode = self.server.async_mode
for handler in self.handlers:
self.server.on(handler[0], handler[1], namespace=handler[2])
for namespace_handler in self.namespace_handlers:
self.server.register_namespace(namespace_handler)
if app is not None:
# here we attach the SocketIO middlware to the SocketIO object so
# it can be referenced later if debug middleware needs to be
# inserted
self.sockio_mw = _SocketIOMiddleware(self.server, app,
socketio_path=resource)
app.wsgi_app = self.sockio_mw
def on(self, message, namespace=None):
"""Decorator to register a SocketIO event handler.
This decorator must be applied to SocketIO event handlers. Example::
@socketio.on('my event', namespace='/chat')
def handle_my_custom_event(json):
print('received json: ' + str(json))
:param message: The name of the event. This is normally a user defined
string, but a few event names are already defined. Use
``'message'`` to define a handler that takes a string
payload, ``'json'`` to define a handler that takes a
JSON blob payload, ``'connect'`` or ``'disconnect'``
to create handlers for connection and disconnection
events.
:param namespace: The namespace on which the handler is to be
registered. Defaults to the global namespace.
"""
namespace = namespace or '/'
def decorator(handler):
@wraps(handler)
def _handler(sid, *args):
return self._handle_event(handler, message, namespace, sid,
*args)
if self.server:
self.server.on(message, _handler, namespace=namespace)
else:
self.handlers.append((message, _handler, namespace))
return handler
return decorator
def on_error(self, namespace=None):
"""Decorator to define a custom error handler for SocketIO events.
This decorator can be applied to a function that acts as an error
handler for a namespace. This handler will be invoked when a SocketIO
event handler raises an exception. The handler function must accept one
argument, which is the exception raised. Example::
@socketio.on_error(namespace='/chat')
def chat_error_handler(e):
print('An error has occurred: ' + str(e))
:param namespace: The namespace for which to register the error
handler. Defaults to the global namespace.
"""
namespace = namespace or '/'
def decorator(exception_handler):
if not callable(exception_handler):
raise ValueError('exception_handler must be callable')
self.exception_handlers[namespace] = exception_handler
return exception_handler
return decorator
def on_error_default(self, exception_handler):
"""Decorator to define a default error handler for SocketIO events.
This decorator can be applied to a function that acts as a default
error handler for any namespaces that do not have a specific handler.
Example::
@socketio.on_error_default
def error_handler(e):
print('An error has occurred: ' + str(e))
"""
if not callable(exception_handler):
raise ValueError('exception_handler must be callable')
self.default_exception_handler = exception_handler
return exception_handler
def on_event(self, message, handler, namespace=None):
"""Register a SocketIO event handler.
``on_event`` is the non-decorator version of ``'on'``.
Example::
def on_foo_event(json):
print('received json: ' + str(json))
socketio.on_event('my event', on_foo_event, namespace='/chat')
:param message: The name of the event. This is normally a user defined
string, but a few event names are already defined. Use
``'message'`` to define a handler that takes a string
payload, ``'json'`` to define a handler that takes a
JSON blob payload, ``'connect'`` or ``'disconnect'``
to create handlers for connection and disconnection
events.
:param handler: The function that handles the event.
:param namespace: The namespace on which the handler is to be
registered. Defaults to the global namespace.
"""
self.on(message, namespace=namespace)(handler)
def event(self, *args, **kwargs):
"""Decorator to register an event handler.
This is a simplified version of the ``on()`` method that takes the
event name from the decorated function.
Example usage::
@socketio.event
def my_event(data):
print('Received data: ', data)
The above example is equivalent to::
@socketio.on('my_event')
def my_event(data):
print('Received data: ', data)
A custom namespace can be given as an argument to the decorator::
@socketio.event(namespace='/test')
def my_event(data):
print('Received data: ', data)
"""
if len(args) == 1 and len(kwargs) == 0 and callable(args[0]):
# the decorator was invoked without arguments
# args[0] is the decorated function
return self.on(args[0].__name__)(args[0])
else:
# the decorator was invoked with arguments
def set_handler(handler):
return self.on(handler.__name__, *args, **kwargs)(handler)
return set_handler
def on_namespace(self, namespace_handler):
if not isinstance(namespace_handler, Namespace):
raise ValueError('Not a namespace instance.')
namespace_handler._set_socketio(self)
if self.server:
self.server.register_namespace(namespace_handler)
else:
self.namespace_handlers.append(namespace_handler)
def emit(self, event, *args, **kwargs):
"""Emit a server generated SocketIO event.
This function emits a SocketIO event to one or more connected clients.
A JSON blob can be attached to the event as payload. This function can
be used outside of a SocketIO event context, so it is appropriate to
use when the server is the originator of an event, outside of any
client context, such as in a regular HTTP request handler or a
background task. Example::
@app.route('/ping')
def ping():
socketio.emit('ping event', {'data': 42}, namespace='/chat')
:param event: The name of the user event to emit.
:param args: A dictionary with the JSON data to send as payload.
:param namespace: The namespace under which the message is to be sent.
Defaults to the global namespace.
:param to: Send the message to all the users in the given room. If
this parameter is not included, the event is sent to all
connected users.
:param include_self: ``True`` to include the sender when broadcasting
or addressing a room, or ``False`` to send to
everyone but the sender.
:param skip_sid: The session id of a client to ignore when broadcasting
or addressing a room. This is typically set to the
originator of the message, so that everyone except
that client receive the message. To skip multiple sids
pass a list.
:param callback: If given, this function will be called to acknowledge
that the client has received the message. The
arguments that will be passed to the function are
those provided by the client. Callback functions can
only be used when addressing an individual client.
"""
namespace = kwargs.pop('namespace', '/')
to = kwargs.pop('to', kwargs.pop('room', None))
include_self = kwargs.pop('include_self', True)
skip_sid = kwargs.pop('skip_sid', None)
if not include_self and not skip_sid:
skip_sid = flask.request.sid
callback = kwargs.pop('callback', None)
if callback:
# wrap the callback so that it sets app app and request contexts
sid = None
if has_request_context():
sid = getattr(flask.request, 'sid', None)
original_callback = callback
def _callback_wrapper(*args):
return self._handle_event(original_callback, None, namespace,
sid, *args)
if sid:
# the callback wrapper above will install a request context
# before invoking the original callback
# we only use it if the emit was issued from a Socket.IO
# populated request context (i.e. request.sid is defined)
callback = _callback_wrapper
self.server.emit(event, *args, namespace=namespace, to=to,
skip_sid=skip_sid, callback=callback, **kwargs)
def send(self, data, json=False, namespace=None, to=None,
callback=None, include_self=True, skip_sid=None, **kwargs):
"""Send a server-generated SocketIO message.
This function sends a simple SocketIO message to one or more connected
clients. The message can be a string or a JSON blob. This is a simpler
version of ``emit()``, which should be preferred. This function can be
used outside of a SocketIO event context, so it is appropriate to use
when the server is the originator of an event.
:param data: The message to send, either a string or a JSON blob.
:param json: ``True`` if ``message`` is a JSON blob, ``False``
otherwise.
:param namespace: The namespace under which the message is to be sent.
Defaults to the global namespace.
:param to: Send the message only to the users in the given room. If
this parameter is not included, the message is sent to all
connected users.
:param include_self: ``True`` to include the sender when broadcasting
or addressing a room, or ``False`` to send to
everyone but the sender.
:param skip_sid: The session id of a client to ignore when broadcasting
or addressing a room. This is typically set to the
originator of the message, so that everyone except
that client receive the message. To skip multiple sids
pass a list.
:param callback: If given, this function will be called to acknowledge
that the client has received the message. The
arguments that will be passed to the function are
those provided by the client. Callback functions can
only be used when addressing an individual client.
"""
skip_sid = flask.request.sid if not include_self else skip_sid
if json:
self.emit('json', data, namespace=namespace, to=to,
skip_sid=skip_sid, callback=callback, **kwargs)
else:
self.emit('message', data, namespace=namespace, to=to,
skip_sid=skip_sid, callback=callback, **kwargs)
def close_room(self, room, namespace=None):
"""Close a room.
This function removes any users that are in the given room and then
deletes the room from the server. This function can be used outside
of a SocketIO event context.
:param room: The name of the room to close.
:param namespace: The namespace under which the room exists. Defaults
to the global namespace.
"""
self.server.close_room(room, namespace)
def run(self, app, host=None, port=None, **kwargs): # pragma: no cover
"""Run the SocketIO web server.
:param app: The Flask application instance.
:param host: The hostname or IP address for the server to listen on.
Defaults to 127.0.0.1.
:param port: The port number for the server to listen on. Defaults to
5000.
:param debug: ``True`` to start the server in debug mode, ``False`` to
start in normal mode.
:param use_reloader: ``True`` to enable the Flask reloader, ``False``
to disable it.
:param reloader_options: A dictionary with options that are passed to
the Flask reloader, such as ``extra_files``,
``reloader_type``, etc.
:param extra_files: A list of additional files that the Flask
reloader should watch. Defaults to ``None``.
Deprecated, use ``reloader_options`` instead.
:param log_output: If ``True``, the server logs all incoming
connections. If ``False`` logging is disabled.
Defaults to ``True`` in debug mode, ``False``
in normal mode. Unused when the threading async
mode is used.
:param kwargs: Additional web server options. The web server options
are specific to the server used in each of the supported
async modes. Note that options provided here will
not be seen when using an external web server such
as gunicorn, since this method is not called in that
case.
"""
if host is None:
host = '127.0.0.1'
if port is None:
server_name = app.config['SERVER_NAME']
if server_name and ':' in server_name:
port = int(server_name.rsplit(':', 1)[1])
else:
port = 5000
debug = kwargs.pop('debug', app.debug)
log_output = kwargs.pop('log_output', debug)
use_reloader = kwargs.pop('use_reloader', debug)
extra_files = kwargs.pop('extra_files', None)
reloader_options = kwargs.pop('reloader_options', {})
if extra_files:
reloader_options['extra_files'] = extra_files
app.debug = debug
if app.debug and self.server.eio.async_mode != 'threading':
# put the debug middleware between the SocketIO middleware
# and the Flask application instance
#
# mw1 mw2 mw3 Flask app
# o ---- o ---- o ---- o
# /
# o Flask-SocketIO
# \ middleware
# o
# Flask-SocketIO WebSocket handler
#
# BECOMES
#
# dbg-mw mw1 mw2 mw3 Flask app
# o ---- o ---- o ---- o ---- o
# /
# o Flask-SocketIO
# \ middleware
# o
# Flask-SocketIO WebSocket handler
#
self.sockio_mw.wsgi_app = DebuggedApplication(
self.sockio_mw.wsgi_app, evalex=True)
if self.server.eio.async_mode == 'threading':
try:
import simple_websocket # noqa: F401
except ImportError:
from werkzeug._internal import _log
_log('warning', 'WebSocket transport not available. Install '
'simple-websocket for improved performance.')
app.run(host=host, port=port, threaded=True,
use_reloader=use_reloader, **reloader_options, **kwargs)
elif self.server.eio.async_mode == 'eventlet':
def run_server():
import eventlet
import eventlet.wsgi
import eventlet.green
addresses = eventlet.green.socket.getaddrinfo(host, port)
if not addresses:
raise RuntimeError(
'Could not resolve host to a valid address')
eventlet_socket = eventlet.listen(addresses[0][4],
addresses[0][0])
# If provided an SSL argument, use an SSL socket
ssl_args = ['keyfile', 'certfile', 'server_side', 'cert_reqs',
'ssl_version', 'ca_certs',
'do_handshake_on_connect', 'suppress_ragged_eofs',
'ciphers']
ssl_params = {k: kwargs[k] for k in kwargs
if k in ssl_args and kwargs[k] is not None}
for k in ssl_args:
kwargs.pop(k, None)
if len(ssl_params) > 0:
ssl_params['server_side'] = True # Listening requires true
eventlet_socket = eventlet.wrap_ssl(eventlet_socket,
**ssl_params)
eventlet.wsgi.server(eventlet_socket, app,
log_output=log_output, **kwargs)
if use_reloader:
run_with_reloader(run_server, **reloader_options)
else:
run_server()
elif self.server.eio.async_mode == 'gevent':
from gevent import pywsgi
try:
from geventwebsocket.handler import WebSocketHandler
websocket = True
except ImportError:
app.logger.warning(
'WebSocket transport not available. Install '
'gevent-websocket for improved performance.')
websocket = False
log = 'default'
if not log_output:
log = None
if websocket:
self.wsgi_server = pywsgi.WSGIServer(
(host, port), app, handler_class=WebSocketHandler,
log=log, **kwargs)
else:
self.wsgi_server = pywsgi.WSGIServer((host, port), app,
log=log, **kwargs)
if use_reloader:
# monkey patching is required by the reloader
from gevent import monkey
monkey.patch_thread()
monkey.patch_time()
def run_server():
self.wsgi_server.serve_forever()
run_with_reloader(run_server, **reloader_options)
else:
self.wsgi_server.serve_forever()
def stop(self):
"""Stop a running SocketIO web server.
This method must be called from a HTTP or SocketIO handler function.
"""
if self.server.eio.async_mode == 'threading':
func = flask.request.environ.get('werkzeug.server.shutdown')
if func:
func()
else:
raise RuntimeError('Cannot stop unknown web server')
elif self.server.eio.async_mode == 'eventlet':
raise SystemExit
elif self.server.eio.async_mode == 'gevent':
self.wsgi_server.stop()
def start_background_task(self, target, *args, **kwargs):
"""Start a background task using the appropriate async model.
This is a utility function that applications can use to start a
background task using the method that is compatible with the
selected async mode.
:param target: the target function to execute.
:param args: arguments to pass to the function.
:param kwargs: keyword arguments to pass to the function.
This function returns an object compatible with the `Thread` class in
the Python standard library. The `start()` method on this object is
already called by this function.
"""
return self.server.start_background_task(target, *args, **kwargs)
def sleep(self, seconds=0):
"""Sleep for the requested amount of time using the appropriate async
model.
This is a utility function that applications can use to put a task to
sleep without having to worry about using the correct call for the
selected async mode.
"""
return self.server.sleep(seconds)
def test_client(self, app, namespace=None, query_string=None,
headers=None, auth=None, flask_test_client=None):
"""The Socket.IO test client is useful for testing a Flask-SocketIO
server. It works in a similar way to the Flask Test Client, but
adapted to the Socket.IO server.
:param app: The Flask application instance.
:param namespace: The namespace for the client. If not provided, the
client connects to the server on the global
namespace.
:param query_string: A string with custom query string arguments.
:param headers: A dictionary with custom HTTP headers.
:param auth: Optional authentication data, given as a dictionary.
:param flask_test_client: The instance of the Flask test client
currently in use. Passing the Flask test
client is optional, but is necessary if you
want the Flask user session and any other
cookies set in HTTP routes accessible from
Socket.IO events.
"""
return SocketIOTestClient(app, self, namespace=namespace,
query_string=query_string, headers=headers,
auth=auth,
flask_test_client=flask_test_client)
def _handle_event(self, handler, message, namespace, sid, *args):
environ = self.server.get_environ(sid, namespace=namespace)
if not environ:
# we don't have record of this client, ignore this event
return '', 400
app = environ['flask.app']
with app.request_context(environ):
if self.manage_session:
# manage a separate session for this client's Socket.IO events
# created as a copy of the regular user session
if 'saved_session' not in environ:
environ['saved_session'] = _ManagedSession(flask.session)
session_obj = environ['saved_session']
else:
# let Flask handle the user session
# for cookie based sessions, this effectively freezes the
# session to its state at connection time
# for server-side sessions, this allows HTTP and Socket.IO to
# share the session, with both having read/write access to it
session_obj = flask.session._get_current_object()
_request_ctx_stack.top.session = session_obj
flask.request.sid = sid
flask.request.namespace = namespace
flask.request.event = {'message': message, 'args': args}
try:
if message == 'connect':
auth = args[1] if len(args) > 1 else None
try:
ret = handler(auth)
except TypeError:
ret = handler()
else:
ret = handler(*args)
except:
err_handler = self.exception_handlers.get(
namespace, self.default_exception_handler)
if err_handler is None:
raise
type, value, traceback = sys.exc_info()
return err_handler(value)
if not self.manage_session:
# when Flask is managing the user session, it needs to save it
if not hasattr(session_obj, 'modified') or \
session_obj.modified:
resp = app.response_class()
app.session_interface.save_session(app, session_obj, resp)
return ret
def emit(event, *args, **kwargs):
"""Emit a SocketIO event.
This function emits a SocketIO event to one or more connected clients. A
JSON blob can be attached to the event as payload. This is a function that
can only be called from a SocketIO event handler, as in obtains some
information from the current client context. Example::
@socketio.on('my event')
def handle_my_custom_event(json):
emit('my response', {'data': 42})
:param event: The name of the user event to emit.
:param args: A dictionary with the JSON data to send as payload.
:param namespace: The namespace under which the message is to be sent.
Defaults to the namespace used by the originating event.
A ``'/'`` can be used to explicitly specify the global
namespace.
:param callback: Callback function to invoke with the client's
acknowledgement.
:param broadcast: ``True`` to send the message to all clients, or ``False``
to only reply to the sender of the originating event.
:param to: Send the message to all the users in the given room. If this
argument is not set and ``broadcast`` is ``False``, then the
message is sent only to the originating user.
:param include_self: ``True`` to include the sender when broadcasting or
addressing a room, or ``False`` to send to everyone
but the sender.
:param skip_sid: The session id of a client to ignore when broadcasting
or addressing a room. This is typically set to the
originator of the message, so that everyone except
that client receive the message. To skip multiple sids
pass a list.
:param ignore_queue: Only used when a message queue is configured. If
set to ``True``, the event is emitted to the
clients directly, without going through the queue.
This is more efficient, but only works when a
single server process is used, or when there is a
single addressee. It is recommended to always leave
this parameter with its default value of ``False``.
"""
if 'namespace' in kwargs:
namespace = kwargs['namespace']
else:
namespace = flask.request.namespace
callback = kwargs.get('callback')
broadcast = kwargs.get('broadcast')
to = kwargs.pop('to', kwargs.pop('room', None))
if to is None and not broadcast:
to = flask.request.sid
include_self = kwargs.get('include_self', True)
skip_sid = kwargs.get('skip_sid')
ignore_queue = kwargs.get('ignore_queue', False)
socketio = flask.current_app.extensions['socketio']
return socketio.emit(event, *args, namespace=namespace, to=to,
include_self=include_self, skip_sid=skip_sid,
callback=callback, ignore_queue=ignore_queue)
def send(message, **kwargs):
"""Send a SocketIO message.
This function sends a simple SocketIO message to one or more connected
clients. The message can be a string or a JSON blob. This is a simpler
version of ``emit()``, which should be preferred. This is a function that
can only be called from a SocketIO event handler.
:param message: The message to send, either a string or a JSON blob.
:param json: ``True`` if ``message`` is a JSON blob, ``False``
otherwise.
:param namespace: The namespace under which the message is to be sent.
Defaults to the namespace used by the originating event.
An empty string can be used to use the global namespace.
:param callback: Callback function to invoke with the client's
acknowledgement.
:param broadcast: ``True`` to send the message to all connected clients, or
``False`` to only reply to the sender of the originating
event.
:param to: Send the message to all the users in the given room. If this
argument is not set and ``broadcast`` is ``False``, then the
message is sent only to the originating user.
:param include_self: ``True`` to include the sender when broadcasting or
addressing a room, or ``False`` to send to everyone
but the sender.
:param skip_sid: The session id of a client to ignore when broadcasting
or addressing a room. This is typically set to the
originator of the message, so that everyone except
that client receive the message. To skip multiple sids
pass a list.
:param ignore_queue: Only used when a message queue is configured. If
set to ``True``, the event is emitted to the
clients directly, without going through the queue.
This is more efficient, but only works when a
single server process is used, or when there is a
single addressee. It is recommended to always leave
this parameter with its default value of ``False``.
"""
json = kwargs.get('json', False)
if 'namespace' in kwargs:
namespace = kwargs['namespace']
else:
namespace = flask.request.namespace
callback = kwargs.get('callback')
broadcast = kwargs.get('broadcast')
to = kwargs.pop('to', kwargs.pop('room', None))
if to is None and not broadcast:
to = flask.request.sid
include_self = kwargs.get('include_self', True)
skip_sid = kwargs.get('skip_sid')
ignore_queue = kwargs.get('ignore_queue', False)
socketio = flask.current_app.extensions['socketio']
return socketio.send(message, json=json, namespace=namespace, to=to,
include_self=include_self, skip_sid=skip_sid,
callback=callback, ignore_queue=ignore_queue)
def join_room(room, sid=None, namespace=None):
"""Join a room.
This function puts the user in a room, under the current namespace. The
user and the namespace are obtained from the event context. This is a
function that can only be called from a SocketIO event handler. Example::
@socketio.on('join')
def on_join(data):
username = session['username']
room = data['room']
join_room(room)
send(username + ' has entered the room.', room=room)
:param room: The name of the room to join.
:param sid: The session id of the client. If not provided, the client is
obtained from the request context.
:param namespace: The namespace for the room. If not provided, the
namespace is obtained from the request context.
"""
socketio = flask.current_app.extensions['socketio']
sid = sid or flask.request.sid
namespace = namespace or flask.request.namespace
socketio.server.enter_room(sid, room, namespace=namespace)
def leave_room(room, sid=None, namespace=None):
"""Leave a room.
This function removes the user from a room, under the current namespace.
The user and the namespace are obtained from the event context. Example::
@socketio.on('leave')
def on_leave(data):
username = session['username']
room = data['room']
leave_room(room)
send(username + ' has left the room.', room=room)
:param room: The name of the room to leave.
:param sid: The session id of the client. If not provided, the client is
obtained from the request context.
:param namespace: The namespace for the room. If not provided, the
namespace is obtained from the request context.
"""
socketio = flask.current_app.extensions['socketio']
sid = sid or flask.request.sid
namespace = namespace or flask.request.namespace
socketio.server.leave_room(sid, room, namespace=namespace)
def close_room(room, namespace=None):
"""Close a room.
This function removes any users that are in the given room and then deletes
the room from the server.
:param room: The name of the room to close.
:param namespace: The namespace for the room. If not provided, the
namespace is obtained from the request context.
"""
socketio = flask.current_app.extensions['socketio']
namespace = namespace or flask.request.namespace
socketio.server.close_room(room, namespace=namespace)
def rooms(sid=None, namespace=None):
"""Return a list of the rooms the client is in.
This function returns all the rooms the client has entered, including its
own room, assigned by the Socket.IO server.
:param sid: The session id of the client. If not provided, the client is
obtained from the request context.
:param namespace: The namespace for the room. If not provided, the
namespace is obtained from the request context.
"""
socketio = flask.current_app.extensions['socketio']
sid = sid or flask.request.sid
namespace = namespace or flask.request.namespace
return socketio.server.rooms(sid, namespace=namespace)
def disconnect(sid=None, namespace=None, silent=False):
"""Disconnect the client.
This function terminates the connection with the client. As a result of
this call the client will receive a disconnect event. Example::
@socketio.on('message')
def receive_message(msg):
if is_banned(session['username']):
disconnect()
else:
# ...
:param sid: The session id of the client. If not provided, the client is
obtained from the request context.
:param namespace: The namespace for the room. If not provided, the
namespace is obtained from the request context.
:param silent: this option is deprecated.
"""
socketio = flask.current_app.extensions['socketio']
sid = sid or flask.request.sid
namespace = namespace or flask.request.namespace
return socketio.server.disconnect(sid, namespace=namespace)