Django频道，如何在连接后开始使用

问题描述

我试图了解Django渠道中消费者的流向。

我写了下面的使用者，它对查询集进行一次小检查，并每分钟返回一个结果。

我已经能够与WebSocket建立连接，但是我不明白我以后如何开始使用它，再次，我需要它每60秒运行一次检查，因此以某种方式使用睡眠吗？

消费者：

class CameraOnlineConsumer(JsonWebsocketConsumer):
    def connect(self):
        self.farm_name = '1'
        self.farm_group_name = 'farm_%s' % self.farm_name

        # Join farm group
        async_to_sync(self.channel_layer.group_add)(
            self.farm_group_name,self.channel_name
        )
        # Todo: Once working,add Auth
        # accept connection
        self.accept()

    def camera(self,event):
        result = self.check_events()  # Get updated camera status
        async_to_sync(self.channel_layer.group_send)(
            self.farm_group_name,# send result to group
            {
                'type': 'check_events','message': result
            }
        )

    @database_sync_to_async
    def get_events(self):
        return PastureEvent.objects.filter(result=8,farm_id=self.farm_name,processed=False).order_by('-time_stamp')[
               :2]

    @database_sync_to_async
    def update_event(self,query_set):
        PastureEvent.objects.select_for_update().filter(id=query_set[1].id).update(processed=True)

    def check_events(self):
        minute_delta = timedelta(seconds=60)
        query_set = self.get_events()
        if not query_set:
            result = {'camera status': CameraOffline.default_detail,}
            return result
        elif len(query_set) == 1:  # means that no new events has been recorded since last check.
            result = {'camera status': CameraOnline.default_detail,'first time_stamp': str(query_set[0].time_stamp)}
            return result
        elif len(query_set) >= 2:  # two relevant events received.
            difference = query_set[0].time_stamp - query_set[1].time_stamp
            if difference <= minute_delta:
                if query_set[1]:
                    # query_set[1].processed = True & query_set[1].save() didn't work,why?
                    self.update_event(query_set=query_set)
                else:
                    pass
                # time difference between them is under/equal to the desired time difference between events.
                result = {'camera status': CameraOnline.default_detail,'first time_stamp': str(query_set[0].time_stamp),'last time_stamp': str(query_set[1].time_stamp)}
                return result
            else:
                if query_set[1]:
                    self.update_event(query_set=query_set)
                else:
                    pass
                # two events exist but the difference between them is bigger then one minute,if changed in the next
                # check it would be updated to camera online.
                result = {'camera status': CameraOnline.default_detail,'first time_stamp': str(query_set[0].time_stamp)}
                return result
        else:
            # For Now,every other case should result in a camera offline msg as well.
            return {'camera status': CameraOffline.default_detail}

一个基本的JS使用者：

const ws = new WebSocket("ws://127.0.0.1:8000/ws/camera_online/connect/camera");
ws.onmessage = function(event) {
    console.log(event.data);
};

ws.OPEN

返回1

解决方法

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