Question

我使用以下代码为javascript EventSource

实现后端

from flask import Flask, Response
from time import sleep
import time

class ServerSentEvent(object):

    def __init__(self, data):
        self.data = data
        self.event = None
        self.id = None
        self.desc_map = {
            self.data : "data",
            self.event : "event",
            self.id : "id",
            self.retry: 500
        }

    def encode(self):
        if not self.data:
            return ""
        lines = ["%s: %s" % (v, k) 
                 for k, v in self.desc_map.items() if k]

        return "%s\n\n" % "\n".join(lines)

def stream():
  while True:
    ev = ServerSentEvent('hi ' + str(int(round(time.time()))))
    yield ev
    sleep(0.1)

app = Flask(__name__)

@app.route("/events")
def streamSessionEvents():
  return Response(stream(), mimetype="text/event-stream")


@app.route("/")
def index():
  template = """
     <!doctype html>
    <html>
    <head>
      <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.4/jquery.min.js"></script>
      <script>
        var source = new EventSource('/events')
        source.onmessage = function (event) {
          $('#log').append(event.data + '</br>')
        }
      </script>
    </head>
    <body>
    <div id="log"></div>
    </body>
    </html>
  """
  return(template)

app.run(threaded=True)

然而，EventSource每隔3秒（这是默认值）保持重新连接，因为服务器在每次事件后关闭连接。如何建立连续连接？

Flask流式SSE会在每次事件后关闭连接

0 个答案: