Firefox doesn't restore server-sent events connection

问题

Test case implemented with Python and CherryPy:

import cherrypy, time

class Root():

    @cherrypy.expose
    def index(self):
        return r'''<!DOCTYPE html>
<html>
 <head>
  <title>Server-sent events test</title>
  <style>html,body,#test{height:98%;}</style>
 </head>
 <body>
  <script type="text/javascript">
    document.addEventListener('DOMContentLoaded', function () {
      var source = new EventSource('gettime');
      source.addEventListener('time', function (event) {
        document.getElementById('test').innerHTML += event.data + "\n";
      });
      source.addEventListener('error', function (event){
        console.log('SSE error:', event);
        console.log('SSE state:', source.readyState);
      });
    }, false);
  </script>
  <textarea id="test"></textarea>
 </body>
</html>'''

    @cherrypy.expose
    def gettime(self):
        cherrypy.response.headers["Content-Type"] = "text/event-stream"
        def generator():
            while True:
                time.sleep(1)
                yield "event: time\n" + "data: " + str(time.time()) + "\n\n"
        return generator()
    gettime._cp_config = {'response.stream': True}

if __name__ == '__main__':
    cherrypy.config.update({'server.socket_host': '0.0.0.0'})
    cherrypy.quickstart(Root())

After receiving some messages successfully I manually drop the connection, then in Firefox' web console appears JS Error: The connection to http://localhost:8080/gettime was interrupted while the page was loading.

According to the spec, Clients will reconnect if the connection is closed, but Firefox doesn't. Error event handler reports that the source is in CLOSED state.

CLOSED (numeric value 2) The connection is not open, and the user agent is not trying to reconnect. Either there was a fatal error or the close() method was invoked.
So there was a fatal error?

In Chromium it works, error handler reports that the source is in CONNECTING (0) state (as it should) and connection is automatically restored within a few seconds
Have tried Firefox 26, Firefox 24 ESR and Iceweasel 17 on Linux and Windows platforms, all the same
Have checked raw protocol and headers, looks ok
Have tried to add retry: 3000 to each sent event
Have tried to move JavaScript out of event listener and wrapping it into setTimeout

回答1:

The bug is fixed in Firefox 36.

回答2:

The spec on this stuff is in flux and there is a number of open spec issues related to the reconnection behavior that the spec proposes. I wouldn't rely on any specific reconnection behavior until the spec stabilizes a lot more than it has so far.

来源：https://stackoverflow.com/questions/20837460/firefox-doesnt-restore-server-sent-events-connection

标签

python

html5

firefox

cherrypy

server-sent-events