Python Autobahn websocket

Question

Python可以做的所有事情都给我留下了深刻的印象。我想知道的是，我是否可以实现一个可以调用JavaScript函数的Python脚本。

我使用的Python代码是检测NFC卡并读取唯一的ID，目前我使用Java applet与HTML页面交互。我认为Python在这方面要轻巧得多，也更好。

我尝试的是一个简单的autobahn脚本server.py和一个index.html文件。

在server.py脚本中，我实现了此代码，但它不起作用。

#! /usr/bin/env python

from sys import stdin, exc_info
from time import sleep

from smartcard.CardMonitoring import CardMonitor, CardObserver
from smartcard.util import *
import sys

from twisted.internet import reactor
from twisted.python import log
from twisted.web.server import Site
from twisted.web.static import File

from autobahn.websocket import WebSocketServerFactory, \
                               WebSocketServerProtocol, \
                               listenWS


class EchoServerProtocol(WebSocketServerProtocol):

   # a simple card observer that prints inserted/removed cards
    class printobserver(CardObserver):
        """A simple card observer that is notified
        when cards are inserted/removed from the system and
        prints the list of cards
        """

        def update(self, observable, (addedcards, removedcards)):
            for card in addedcards:
                print "+Inserted: ", toHexString(card.atr)
        #call javascript function with <toHexString(card.atr)> 
            for card in removedcards:
                print "-Removed: ", toHexString(card.atr)
        #call javascript function with <toHexString(card.atr)> 

    try:
        print "Insert or remove a smartcard in the system."
        print "This program will exit in 10 seconds"
        print ""
        cardmonitor = CardMonitor()
        cardobserver = printobserver()
        cardmonitor.addObserver(cardobserver)

        sleep(10)

        # don't forget to remove observer, or the
        # monitor will poll forever...
        cardmonitor.deleteObserver(cardobserver)

        import sys
        if 'win32' == sys.platform:
            print 'press Enter to continue'
            sys.stdin.read(1)

    except:
        print exc_info()[0], ':', exc_info()[1]


if __name__ == '__main__':

   if len(sys.argv) > 1 and sys.argv[1] == 'debug':
      log.startLogging(sys.stdout)
      debug = True
   else:
      debug = False

   factory = WebSocketServerFactory("ws://localhost:9000",
                                    debug = debug,
                                    debugCodePaths = debug)

   factory.protocol = EchoServerProtocol
   factory.setProtocolOptions(allowHixie76 = True)
   listenWS(factory)

   webdir = File(".")
   web = Site(webdir)
   reactor.listenTCP(8080, web)

   reactor.run()

在索引文件中有一个JavaScript函数

function NFCid(msg) {
  alert(msg);
}

如何在server.py中调用此函数

NFCid(toHexString(card.atr))

Answer 1

通常，可以建立一个将数据从运行web(套接字)服务器的WebSocket进程传送到JavaScript函数的Python连接。但是，您必须显式地从JavaScript设置WebSocket连接，并使其连接到服务器进程。然后，您可以将通过WebSocket连接(例如来自Python)传入的任何数据传递给任何JavaScript函数。