Fix an issue with versions of websockets > 4.0

openlp/core/api/websockets.py

@@ -28,7 +28,7 @@ import json
 import logging
 import time
 
-import websockets
+from websockets import serve
 
 from openlp.core.common.mixins import LogMixin, RegistryProperties
 from openlp.core.common.registry import Registry
@@ -38,91 +38,6 @@ from openlp.core.threading import ThreadWorker, run_thread
 log = logging.getLogger(__name__)
 
 
-class WebSocketWorker(ThreadWorker):
-    """
-    A special Qt thread class to allow the WebSockets server to run at the same time as the UI.
-    """
-    def __init__(self, server):
-        """
-        Constructor for the thread class.
-
-        :param server: The http server class.
-        """
-        self.ws_server = server
-        super().__init__()
-
-    def start(self):
-        """
-        Run the worker.
-        """
-        self.ws_server.start_server()
-        self.quit.emit()
-
-    def stop(self):
-        """
-        Stop the websocket server
-        """
-        self.ws_server.stop_server()
-
-
-class WebSocketServer(RegistryProperties, LogMixin):
-    """
-    Wrapper round a server instance
-    """
-    def __init__(self):
-        """
-        Initialise and start the WebSockets server
-        """
-        super(WebSocketServer, self).__init__()
-        if Registry().get_flag('no_web_server'):
-            self.settings_section = 'api'
-            worker = WebSocketWorker(self)
-            run_thread(worker, 'websocket_server')
-
-    def start_server(self):
-        """
-        Start the correct server and save the handler
-        """
-        address = Settings().value(self.settings_section + '/ip address')
-        port = Settings().value(self.settings_section + '/websocket port')
-        self.start_websocket_instance(address, port)
-        # If web socket server start listening
-        if hasattr(self, 'ws_server') and self.ws_server:
-            event_loop = asyncio.new_event_loop()
-            asyncio.set_event_loop(event_loop)
-            event_loop.run_until_complete(self.ws_server)
-            event_loop.run_forever()
-        else:
-            log.debug('Failed to start ws server on port {port}'.format(port=port))
-
-    def stop_server(self):
-        """
-        Stop the websocket server
-        """
-        if hasattr(self.ws_server, 'ws_server'):
-            self.ws_server.ws_server.close()
-        elif hasattr(self.ws_server, 'server'):
-            self.ws_server.server.close()
-
-    def start_websocket_instance(self, address, port):
-        """
-        Start the server
-
-        :param address: The server address
-        :param port: The run port
-        """
-        loop = 1
-        while loop < 4:
-            try:
-                self.ws_server = websockets.serve(self.handle_websocket, address, port)
-                log.debug("Web Socket Server started for class {address} {port}".format(address=address, port=port))
-                break
-            except Exception as e:
-                log.exception('Failed to start ws server {why}'.format(why=e))
-                loop += 1
-                time.sleep(0.1)
-
-    @staticmethod
 async def handle_websocket(request, path):
     """
     Handle web socket requests and return the poll information.
@@ -133,7 +48,7 @@ class WebSocketServer(RegistryProperties, LogMixin):
     :param path: determines the endpoints supported
     :return:
     """
-        log.debug("web socket handler registered with client")
+    log.debug('WebSocket handler registered with client')
     previous_poll = None
     previous_main_poll = None
     poller = Registry().get('poller')
@@ -151,3 +66,59 @@ class WebSocketServer(RegistryProperties, LogMixin):
                 await request.send(main_poll)
                 previous_main_poll = main_poll
             await asyncio.sleep(0.2)
+
+
+class WebSocketWorker(ThreadWorker, RegistryProperties, LogMixin):
+    """
+    A special Qt thread class to allow the WebSockets server to run at the same time as the UI.
+    """
+    def start(self):
+        """
+        Run the worker.
+        """
+        address = Settings().value('api/ip address')
+        port = Settings().value('api/websocket port')
+        # Start the event loop
+        event_loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(event_loop)
+        # Create the websocker server
+        loop = 1
+        self.server = None
+        while not self.server:
+            try:
+                self.server = serve(handle_websocket, address, port)
+                log.debug('WebSocket server started on {addr}:{port}'.format(addr=address, port=port))
+            except Exception as e:
+                log.exception('Failed to start WebSocket server')
+                loop += 1
+                time.sleep(0.1)
+            if not self.server and loop > 3:
+                log.error('Unable to start WebSocket server {addr}:{port}, giving up'.format(addr=address, port=port))
+        if self.server:
+            # If the websocket server exists, start listening
+            event_loop.run_until_complete(self.server)
+            event_loop.run_forever()
+        self.quit.emit()
+
+    def stop(self):
+        """
+        Stop the websocket server
+        """
+        if hasattr(self.server, 'ws_server'):
+            self.server.ws_server.close()
+        elif hasattr(self.server, 'server'):
+            self.server.server.close()
+
+
+class WebSocketServer(RegistryProperties, LogMixin):
+    """
+    Wrapper round a server instance
+    """
+    def __init__(self):
+        """
+        Initialise and start the WebSockets server
+        """
+        super(WebSocketServer, self).__init__()
+        if Registry().get_flag('no_web_server'):
+            worker = WebSocketWorker()
+            run_thread(worker, 'websocket_server')