Can't get JSON data from client side

Question

I want to send JSON data from client side to server side.

Client side:

function send() {
    var formData = {
        firstname: $("#name").val(),
        lastname: $("#lastname").val()
    }

    console.log("sending: " + JSON.stringify(formData));

    $.ajax({
        type: "POST",
        contentType: "application/json",
        url: "/dat",
        data: JSON.stringify(formData),
        dataType: 'json',
        success: function(customer) {
            console.log(JSON.stringify(customer));
        },
        error: function(e) {
            alert("Error!")
            console.log("ERROR: ", e);
        }
    });
}

Server side:

app.post("/dat", function (req, res) {
    console.log(JSON.stringify(req.body)); // return undefined
    res.end(JSON.stringify({ "nine": 9, "ten": 10, "eleven": 11 }));
});

I tried everything, but JSON.stringify(req.body) return only undefined. Sending data from server to client side working just fine... Any suggestions?

I'm going to assume you're using Express. Have you installed [`body-parser`](https://www.npmjs.com/package/body-parser#installation)? See https://stackoverflow.com/a/24635296/965834 for usage example. — Jeto, Feb 16 '19 at 12:45
@Jeto yes, I got that. I have this: `const bodyParser = require("body-parser");` and `app.use(bodyParser.json());` — KoRaP CZ, Feb 16 '19 at 12:56
@Jeto yes, I am sure... I uploaded my code to gitlab: https://gitlab.com/JaroslavVond/nodejs/tree/master/NodeServer — KoRaP CZ, Feb 16 '19 at 13:42

score 2 · Accepted Answer · answered Feb 16 '19 at 14:09

2

You're resetting app here with:

var app = express();

Remove that line.

answered Feb 16 '19 at 14:09

Jeto

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Yes, that was the problem, Thank you so much!! – KoRaP CZ Feb 16 '19 at 14:23
If I get it right... every time when I did POST, the server restarted or set some default settings? – KoRaP CZ Feb 16 '19 at 14:28
1

@KoRaPCZ More like, everything that happened before that line got cancelled because you replaced the existing `app` variable with a brand new one. The session thing, the body-parser setup, etc. – Jeto Feb 16 '19 at 14:32
I see. Thank you for help – KoRaP CZ Feb 16 '19 at 14:35

Can't get JSON data from client side

1 Answers1