The EventSource interface is used to receive server-sent events. It connects to a server over HTTP and receives events in text/event-stream format without closing the connection. aiohttp-sse provides support for server-sent events for aiohttp.
Installation process as simple as:
$ pip install aiohttp-sse
import asyncio
from datetime import datetime
from aiohttp import web
from aiohttp_sse import sse_response
async def hello(request: web.Request) -> web.StreamResponse:
async with sse_response(request) as resp:
while resp.is_connected():
time_dict = {"time": f"Server Time : {datetime.now()}"}
data = json.dumps(time_dict, indent=2)
print(data)
await resp.send(data)
await asyncio.sleep(1)
return resp
async def index(_request: web.Request) -> web.StreamResponse:
html = """
<html>
<body>
<script>
var eventSource = new EventSource("/hello");
eventSource.addEventListener("message", event => {
document.getElementById("response").innerText = event.data;
});
</script>
<h1>Response from server:</h1>
<div id="response"></div>
</body>
</html>
"""
return web.Response(text=html, content_type="text/html")
app = web.Application()
app.router.add_route("GET", "/hello", hello)
app.router.add_route("GET", "/", index)
web.run_app(app, host="127.0.0.1", port=8080)
- http://www.w3.org/TR/2011/WD-eventsource-20110310/
- https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events
- aiohttp 3+
The aiohttp-sse is offered under Apache 2.0 license.