Kobojunkie Kobojunkie - 1 year ago 110
Javascript Question

TypeError: Cannot read property 'handle' of undefined --- if (fn.handle && fn.set) mount_app = fn

I would appreciate some help with this please. Not certain exactly sure what to this means as this is my first time working with node and express. I set up express to use with node, and tried to follow the information on the site Express.js . Would appreciate some help understanding what I may be missing here please.

if (fn.handle && fn.set) mount_app = fn;
TypeError: Cannot read property 'handle' of undefined
at Function.app.use (....\node_modules\express\lib\application.js:178:9)
at Object.<anonymous> (....\app.js:18:5)
at Module._compile (module.js:456:26)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Function.Module.runMain (module.js:497:10)
at startup (node.js:119:16)
at node.js:906:3

* Module dependencies.
var http = require('http');
//var express = require('../..');
var module = require("module")
var logger = require('morgan');
var express = require('express');
var app = module.exports = express();
var silent = 'test' == process.env.NODE_ENV;
var httpServer = http.createServer(app);
var bodyParser = require('body-parser');
var methodOverride = require('method-override');
// app middleware
app.use(express.static(__dirname + '/public'));
* CORS support.
api.all('*', function(req, res, next)
if (!req.get('Origin')) return next();// use "*" here to accept any origin
res.set('Access-Control-Allow-Origin', 'http://localhost:3000');
res.set('Access-Control-Allow-Methods', 'GET, POST');
res.set('Access-Control-Allow-Headers', 'X-Requested-With, Content-Type');
res.set('Access-Control-Allow-Max-Age', 3600);
if ('OPTIONS' == req.method) return res.send(200);
// middleware with an arity of 4 are considered error handling middleware. When you next(err)
// it will be passed through the defined middleware in order, but ONLY those with an arity of 4, ignoring regular middleware.
var clientErrorHandler=function(err, req, res, next) {
if (req.xhr) {// whatever you want here, feel free to populate properties on `err` to treat it differently in here.
res.send(err.status || 500, { error: err.message });
{ next(err);}
// create an error with .status. we can then use the property in our custom error handler (Connect repects this prop as well)
var error=function (status, msg) {
var err = new Error(msg);
err.status = status;
return err;
var logErrors=function (err, req, res, next) {
var errorHandler=function (err, req, res, next) {
res.render('error', { error: err });
// general config
app.set('views', __dirname + '/views');
//app.set('view engine', 'jade');
// our custom "verbose errors" setting which we can use in the templates via settings['verbose errors']
app.enable('verbose errors');// disable them in production use $ NODE_ENV=production node examples/error-pages
if ('production' == app.settings.env) {app.disable('verbose errors');}
silent || app.use(logger('dev'));
// Routes
app.get('/404', function(req, res, next){
next();// trigger a 404 since no other middleware will match /404 after this one, and we're not responding here

app.get('/403', function(req, res, next){// trigger a 403 error
var err = new Error('not allowed!');
err.status = 403;

app.get('/500', function(req, res, next){// trigger a generic (500) error
next(new Error('keyboard cat!'));

// Error handlers

// Since this is the last non-error-handling middleware use()d, we assume 404, as nothing else responded.
// $ curl http://localhost:3000/notfound
// $ curl http://localhost:3000/notfound -H "Accept: application/json"
// $ curl http://localhost:3000/notfound -H "Accept: text/plain"
app.use(function(req, res, next){
if (req.accepts('html')) {// respond with html page
res.render('404', { url: req.url });
if (req.accepts('json')) {// respond with json
res.send({ error: 'Not found' });
res.type('txt').send('Not found');// default to plain-text. send()

// error-handling middleware, take the same form as regular middleware, however they require an
// arity of 4, aka the signature (err, req, res, next).when connect has an error, it will invoke ONLY error-handling middleware.

// If we were to next() here any remaining non-error-handling middleware would then be executed, or if we next(err) to
// continue passing the error, only error-handling middleware would remain being executed, however here
// we simply respond with an error page.
app.use(function(err, req, res, next){
// we may use properties of the error object here and next(err) appropriately, or if we possibly recovered from the error, simply next().
res.status(err.status || 500);
res.render('500', { error: err });

if (!module.parent) {// assigning to exports will not modify module, must use module.exports
silent || console.log('Express started on port 3000');

Answer Source

The problem is that you're trying to use() a variable that isn't defined yet. If you use the function logErrors(err, req, res, next) { syntax instead of var logErrors=function (err, req, res, next) {, your TypeErrors should go away.

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