Express.js req.body undefined

Question

I have this as configuration of my Express server

app.use(app.router); 
app.use(express.cookieParser());
app.use(express.session({ secret: \"keyboard cat\" }         


        

Answer 1

In case anyone runs into the same issue I was having; I am using a url prefix like

http://example.com/api/

which was setup with router

app.use('/api', router); 

and then I had the following

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));

What fixed my issue was placing the bodyparser configuration above app.use('/api', router);

Final

// setup bodyparser
    app.use(bodyParser.json());
    app.use(bodyParser.urlencoded({ extended: true }));

//this is a fix for the prefix of example.com/api/ so we dont need to code the prefix in every route
    app.use('/api', router); 

Answer 2

express.bodyParser() needs to be told what type of content it is that it's parsing. Therefore, you need to make sure that when you're executing a POST request, that you're including the "Content-Type" header. Otherwise, bodyParser may not know what to do with the body of your POST request.

If you're using curl to execute a POST request containing some JSON object in the body, it would look something like this:

curl -X POST -H "Content-Type: application/json" -d @your_json_file http://localhost:xxxx/someRoute

If using another method, just be sure to set that header field using whatever convention is appropriate.

Answer 3

Building on @kevin-xue said, the content type needs to be declared. In my instance, this was only occurring with IE9 because the XDomainRequest doesn't set a content-type, so bodyparser and expressjs were ignoring the body of the request.

I got around this by setting the content-type explicitly before passing the request through to body parser, like so:

app.use(function(req, res, next) {
    // IE9 doesn't set headers for cross-domain ajax requests
    if(typeof(req.headers['content-type']) === 'undefined'){
        req.headers['content-type'] = "application/json; charset=UTF-8";
    }
    next();
})
.use(bodyParser.json());

Answer 4

Add in your app.js

before the call of the Router

const app = express();
app.use(express.json());

Answer 5

To work, you need to app.use(app.router) after app.use(express.bodyParser()), like that:

app.use(express.bodyParser())
   .use(express.methodOverride())
   .use(app.router);

Answer 6

This issue may be because you have not use body-parser (link)

var express = require('express');
var bodyParser  = require('body-parser');

var app = express();
app.use(bodyParser.json());