Aktivieren Sie CORS in Nodejs mit EJS-Vorlage

Question

Ich erhalte wiederholt Typfehler und leere Antworten von was ein CORS-Problem sein kann. Ich bin neu in Nodejs und habe Probleme beim Aktivieren von CORS in meiner Anwendung. Was mit der folgenden Konfiguration für app.js falsch ist, wo ich

app.all('*',function(req, res, next) { 
    res.header("Access-Control-Allow-Origin", "*"); 
    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept"); 
    next(); 
}); 

unmittelbar nach var app = express() anzuwenden versuchte;

Hier ist die vollständige app.js Datei:

var express = require('express'); 
var path = require('path'); 
var favicon = require('serve-favicon'); 
var logger = require('morgan'); 
var cookieParser = require('cookie-parser'); 
var bodyParser = require('body-parser'); 

var routes = require('./routes/index'); 
var users = require('./routes/users'); 

var app = express(); 

app.all('*',function(req, res, next) { 
    res.header("Access-Control-Allow-Origin", "*"); 
    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept"); 
    next(); 
}); 

// view engine setup 
app.set('views', path.join(__dirname, 'views')); 
app.set('view engine', 'ejs'); 

// uncomment after placing your favicon in /public 
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico'))); 
app.use(logger('dev')); 
app.use(bodyParser.json()); 
app.use(bodyParser.urlencoded({ extended: false })); 
app.use(cookieParser()); 
app.use(express.static(path.join(__dirname, 'public'))); 

app.use('/', routes); 
app.use('/users', users); 

// catch 404 and forward to error handler 
app.use(function(req, res, next) { 
    var err = new Error('Not Found'); 
    err.status = 404; 
    next(err); 
}); 


// error handlers 

// development error handler 
// will print stacktrace 
if (app.get('env') === 'development') { 
    app.use(function(err, req, res, next) { 
    res.status(err.status || 500); 
    res.render('error', { 
     message: err.message, 
     error: err 
    }); 
    }); 
} 

// production error handler 
// no stacktraces leaked to user 
app.use(function(err, req, res, next) { 
    res.status(err.status || 500); 
    res.render('error', { 
    message: err.message, 
    error: {} 
    }); 
}); 


module.exports = app; 

I erhalten konsequent:

OPTIONS http://104.236.99.212:6790/ net::ERR_EMPTY_RESPONSE undefined:1 Uncaught (in promise) TypeError: Failed to fetch(…)

Jede Hilfe dankbar sein würde wirklich! Danke

Answer 1

In Ihrem ExpressJS App auf node.js, gehen Sie wie folgt mit Ihren Routen:

app.use(function(req, res, next) { 
    res.header("Access-Control-Allow-Origin", "*"); 
    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept"); 
    next(); 
}); 

app.get('/', function(req, res, next) { 
    // Handle the get for this route 
}); 

app.post('/', function(req, res, next) { 
// Handle the post for this route 
});