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Implementing Socket IO event handling via Blueprint in Flask-SocketIO - without using a single global socketio object.
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| """ | |
| Flask web application factory. Creates and returns the flask app object. | |
| @see http://flask.pocoo.org/docs/1.0/ | |
| @author Brian Wojtczak | |
| """ | |
| import logging | |
| import os | |
| from flask import Flask | |
| from flask_socketio import SocketIO | |
| def create_app(test_config: dict = None) -> Flask: | |
| # Application instance | |
| app = Flask(__name__) | |
| # SocketIO extension | |
| socketio = SocketIO() | |
| socketio.init_app(app) | |
| # Functionality via blueprints | |
| from . import auth, events | |
| app.register_blueprint(auth.bp) | |
| app.register_blueprint(events.bp) | |
| return app |
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| """ | |
| Dummy Flask Authentication Blueprint. | |
| @author Brian Wojtczak | |
| """ | |
| import functools | |
| import logging | |
| from flask import Blueprint, request, session, abort | |
| logger = logging.getLogger(__name__) | |
| bp = Blueprint('auth', __name__) | |
| def is_logged_in(): | |
| return True | |
| def login_required(view): | |
| """ | |
| View decorator that sends an error to anonymous users. | |
| Use the error handler to provide a friendly user experience. | |
| """ | |
| @functools.wraps(view) | |
| def wrapped_view(**kwargs): | |
| if not is_logged_in(): | |
| abort(401) | |
| return view(**kwargs) | |
| return wrapped_view | |
| @bp.before_app_request | |
| def load_logged_in_user(): | |
| pass # Not implemented | |
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| """ | |
| Flask Blueprint for handling events on the SocketIO stream. | |
| @author Brian Wojtczak | |
| """ | |
| import functools | |
| import logging | |
| import time | |
| from flask import request | |
| from flask_socketio import emit, ConnectionRefusedError, disconnect | |
| from .auth import is_logged_in | |
| from .io_blueprint import IOBlueprint | |
| logger = logging.getLogger(__name__) | |
| bp = IOBlueprint('events', __name__) | |
| def authenticated_only(f): | |
| @functools.wraps(f) | |
| def wrapped(*args, **kwargs): | |
| if not is_logged_in(): | |
| disconnect() | |
| else: | |
| return f(*args, **kwargs) | |
| return wrapped | |
| @bp.on('connect') | |
| def connect(): | |
| if not is_logged_in(): | |
| raise ConnectionRefusedError('unauthorized!') | |
| emit('flash', 'Welcome ' + request.remote_user) # context aware emit | |
| @bp.on('echo') | |
| @authenticated_only | |
| def on_alive(data): | |
| logger.debug(data) | |
| emit('echo', data) # context aware emit | |
| @bp.on('broadcast') | |
| @authenticated_only | |
| def on_broadcast(data): | |
| logger.debug(data) | |
| bp.emit('broadcast', data) # bp.emit same as socketio.emit | |
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| """ | |
| A Flask Blueprint class to be used with Flask-SocketIO. | |
| This class inherits from the Flask Blueprint class so that | |
| we can use the standard Blueprint interface. | |
| Derived from https://github.com/m-housh/io-blueprint | |
| Original work by Michael Housh, [email protected] | |
| Modified by Brian Wojtczak | |
| @author Brian Wojtczak | |
| """ | |
| # noinspection PyPackageRequirements | |
| import socketio | |
| from flask import Blueprint | |
| class IOBlueprint(Blueprint): | |
| def __init__(self, *args, **kwargs): | |
| super().__init__(self, *args, **kwargs) | |
| self.namespace = self.url_prefix or '/' | |
| self._socketio_handlers = [] | |
| self.socketio = None | |
| self.record_once(self.init_socketio) | |
| def init_socketio(self, state): | |
| self.socketio: socketio.Client = state.app.extensions['socketio'] | |
| for f in self._socketio_handlers: | |
| f(self.socketio) | |
| return self.socketio | |
| def on(self, key): | |
| """ A decorator to add a handler to a blueprint. """ | |
| def wrapper(f): | |
| def wrap(sio): | |
| @sio.on(key, namespace=self.namespace) | |
| def wrapped(*args, **kwargs): | |
| return f(*args, **kwargs) | |
| return sio | |
| self._socketio_handlers.append(wrap) | |
| return wrapper | |
| def emit(self, *args, **kwargs): | |
| self.socketio.emit(*args, **kwargs) |
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| Copyright 2020 Brian Wojtczak | |
| Permission is hereby granted, free of charge, to any person obtaining a | |
| copy of this software and associated documentation files (the "Software"), | |
| to deal in the Software without restriction, including without limitation | |
| the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
| and/or sell copies of the Software, and to permit persons to whom the | |
| Software is furnished to do so, subject to the following conditions: | |
| The above copyright notice and this permission notice shall be included | |
| in all copies or substantial portions of the Software. | |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS | |
| OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF | |
| MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. | |
| IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY | |
| CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, | |
| TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE | |
| SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
Author
License?
Added MIT license declaration for you.
I know this is old post, but still. Is this still working? Do you maybe have any idea why this error happens:
if "." in name:
TypeError: argument of type 'IOBlueprint' is not iterable
I get same error with your code and with integrating IOBlueprint into my test project. Thanks in advance.
Author
I used it in a few projects - it works there, but I've not worked on those projects for a while though, so still using older versions of libraries.
eventlet==0.25.1
Flask==1.0.3
Flask-SocketIO==4.1.0
python-socketio==4.2.0
Author
Also please make sure you're using Python 3.
Thank you Brian. It works with those versions. I guess something was changed in some of those modules later I guess. Will deep dive and try to find a fix.
I believe I have found a fix for this. On line 23, delete the first argument to super(). So:
# go from this
class IOBlueprint(Blueprint):
def __init__(self, *args, **kwargs):
super().__init__(self, *args, **kwargs)
# <rest of __init__ is the same>
# to this
class IOBlueprint(Blueprint):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs) # <= notice the lack of the first `self` argument here
# <rest of __init__ is the same>
Author
Thanks @enjoythecode
@enjoythecode Thanks. I tested it today and I can confirm fix works.
Is there anything else that needs to be taken into consideration if this is using https/nginx/gunicon, still can't seem to catch the emits on the server coming from the client, although server->client works as it should. Great code though, thank you.
Author
Is there anything else that needs to be taken into consideration if this is using https/nginx/gunicon, still can't seem to catch the emits on the server coming from the client, although server->client works as it should. Great code though, thank you.
Just the normal considerations for web sockets.
https://www.nginx.com/blog/websocket-nginx/
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License?