Sample python foxglove websocket server for sending GeoJSON.

json_server.py

import asyncio
import json
import time
from foxglove_websocket import run_cancellable
from foxglove_websocket.server import FoxgloveServer, FoxgloveServerListener
from foxglove_websocket.types import ChannelId

async def main():
    class Listener(FoxgloveServerListener):
        def on_subscribe(self, server: FoxgloveServer, channel_id: ChannelId):
            print("First client subscribed to", channel_id)

        def on_unsubscribe(self, server: FoxgloveServer, channel_id: ChannelId):
            print("Last client unsubscribed from", channel_id)

    async with FoxgloveServer("0.0.0.0", 8765, "example server") as server:
        server.set_listener(Listener())
        chan_id = await server.add_channel(
            {
                "topic": "foxglove.GeoJSON",
                "encoding": "json",
                "schemaName": "foxglove.GeoJSON",
                "schema": json.dumps(
                    {
                        "type": "object",
                        "properties": {
                            "geojson": {"type": "string"}
                        },
                    }
                ),
            }
        )

        chan_id_1 = await server.add_channel(
            {
                "topic": "foxglove.LocationFix",
                "encoding": "json",
                "schemaName": "foxglove.LocationFix",
                "schema": json.dumps(
                    {
                        "type": "object",
                        "properties": {
                            "latitude": {"type": "number"},
                            "longitude": {"type": "number"}
                        },
                    }
                ),
            }
        )

        geojson_str = {
                        "type":"FeatureCollection",
                        "features":[
                            {
                                "type":"Feature",
                                "properties":{},
                                "geometry":{
                                    "type":"LineString",
                                    "coordinates":[
                                        [
                                            2.42477416992186,
                                            1.801374964252865
                                        ],
                                        [
                                            2.42082595825194,
                                            1.7846897817763
                                        ],
                                        [
                                            2.4422836303711,
                                            1.78292608704408
                                        ]
                                    ]
                                }
                            },
                            {
                                "type":"Feature",
                                "properties":{},
                                "geometry":{
                                    "type":"Polygon",
                                    "coordinates":[
                                        [
                                            [
                                                2.44314193725585,
                                                1.77342854582093
                                            ],
                                            [
                                                2.43953704833984,
                                                1.76596533600783
                                            ],
                                            [
                                                2.4264907836914,
                                                1.7694934927041
                                            ],
                                            [
                                                2.42700576782227,
                                                1.77817746896081
                                            ],
                                            [
                                                2.44314193725585,
                                                1.77342854582093
                                            ]
                                        ]
                                    ]
                                }
                            },
                            {
                                "type":"Feature",
                                "properties":{
                                    "marker-color":"#7e7e7e",
                                    "marker-size":"medium",
                                    "marker-symbol":"1"
                                },
                                "geometry":{
                                    "type":"Point",
                                    "coordinates":[
                                        2.43284225463867,
                                        1.78943798147498
                                    ]
                                }
                            }
                        ]
                    }
                    
        i = 0
        while True:
            i += 1
            time_ns = time.time_ns()
            await asyncio.sleep(0.2)
            await server.send_message(
                chan_id,
                time_ns,
                json.dumps(
                    {
                    "geojson": json.dumps(geojson_str)
                    }
                ).encode("utf8"),
            )
            await server.send_message(
                chan_id_1,
                time_ns,
                json.dumps(
                    {
                    "latitude": 2.3284225463867,
                    "longitude": 1.78943798147498
                    }
                ).encode("utf8"),
            )
            


if __name__ == "__main__":
    run_cancellable(main())