emit（）不工作[Node.js]

Question

I subscibe to laravel 5 event[channal] update.group and I recive message in console after I trigger event but on client side in browser I don't recive any message. Also after I trigger event I recive message in console and then node server stop working with message:

bash-4.2# node node.js
Listening on Port 3000
Message Recieved: testasdsa
/home/client/public_html/node_modules/ioredis/lib/parsers/javascript.js:216
        throw err;
              ^
SyntaxError: Unexpected token e
    at Object.parse (native)
    at Redis.<anonymous> (/home/client/public_html/node_modules/node.js:10:20)
    at Redis.emit (events.js:110:17)
    at Redis.exports.returnReply (/home/client/public_html/node_modules/ioredis/lib/redis/parser.js:79:16)
    at ReplyParser.<anonymous> (/home/client/public_html/node_modules/ioredis/lib/redis/parser.js:27:10)
    at ReplyParser.emit (events.js:107:17)
    at ReplyParser.send_reply (/home/client/public_html/node_modules/ioredis/lib/parsers/javascript.js:281:8)
    at ReplyParser.execute (/home/client/public_html/node_modules/ioredis/lib/parsers/javascript.js:210:14)
    at Socket.<anonymous> (/home/client/public_html/node_modules/ioredis/lib/redis/event_handler.js:90:22)
    at Socket.emit (events.js:107:17)
    at readableAddChunk (_stream_readable.js:163:16)
    at Socket.Readable.push (_stream_readable.js:126:10)
    at TCP.onread (net.js:538:20)

Here is my node.js file:

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
var Redis = require('ioredis');
var redis = new Redis();
redis.subscribe('update.group', function(err, count) {
});
redis.on('message', function(channel, message) {
    console.log('Message Recieved: ' + message);
    message = JSON.parse(message);
    io.sockets.emit(channel + ':' + message.event, message.data);
});
http.listen(3000, function(){
    console.log('Listening on Port 3000');
});

And for client side:

    var socket = io.connect('127.0.0.1:3000');
    socket.on("update.group", function(message){
    // increase the power everytime we load test route
    console.log(message);
});

Anyone can find what is problem?

Answer 1

It's pretty obvious from your debug output: testasdsa is not valid JSON, so you cannot parse it as such. You will need to change the code that publishes the messages so that it's properly JSON encoded.

Since it looks like you're expecting event and data properties on an object, the publisher would need to be writing something like { "event": "foo", "data": "testasdsa" }.

To fix the problem of browser clients not getting the events, you need to change this in your server script:

io.sockets.emit(channel + ':' + message.event, message.data);

to:

io.sockets.emit(message.event, message.data);

Then just make sure the publisher sends out something like { "event": "update.group", "data": "somedata" }