[英]ReferenceError: io is not defined in NodeJS
我有一個NodeJS項目,並且需要另一個文件中我的app.js文件中定義的變量之一,這可能嗎?
我的密碼
app.js
var app = express();
var io = require('socket.io').listen(app);
...
otherFile.js
var models = require('../models');
var express = require('express');
var path = require('path');
var fs = require("fs"); //To-Delete
var recursive = require('recursive-readdir');
var router = express.Router();
var app = require ('../app.js');
// creating a new websocket to keep the content updated without any AJAX request
app.io.sockets.on('connection', function(socket) {
fs.watchFile(__dirname + '../README.md', function(curr, prev) {
// on file change we can read the new xml
fs.readFile(__dirname + '../README.md', function(err, data) {
if (err) throw err;
// parsing the new xml data and converting them into json file
// var json = parser.toJson(data);
// send the new data to the client
socket.volatile.emit('notification', {message: 'el archivo cambio'});
});
});
});
我在這種情況下得到的錯誤是TypeError: Cannot read property 'sockets' of undefined
塊引用
當您這樣做時:
var io = require('socket.io').listen(app);
您只需創建一個局部變量,該局部變量僅在該文件的范圍內可見。
如果您想在導入app
之后使用app.io
從另一個文件訪問它,則需要:
將io
添加為應用程序的屬性:
app.io = io;
或簡單地將兩者結合起來:
app.io = require('socket.io').listen(app);
從socket.io文檔,這應該工作:
var app = require('express')();
var server = require('http').Server(app);
var io = require('socket.io')(server);
io.sockets.on('connection', function(socket) {
// ... your code
});
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