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.serving import run_with_reloader from .namespace import Namespace from .test_client import SocketIOTestClient __version__ = '5.0.2dev' 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 tot he 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): """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 extra_files: A list of additional files that the Flask reloader should watch. Defaults to ``None`` :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) 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': from werkzeug._internal import _log _log('warning', 'WebSocket transport not available. Install ' 'eventlet or gevent and gevent-websocket for ' 'improved performance.') app.run(host=host, port=port, threaded=True, use_reloader=use_reloader, **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} if len(ssl_params) > 0: for k in ssl_params: kwargs.pop(k) 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, extra_files=extra_files) 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, extra_files=extra_files) 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, 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 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, 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': 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)