How to post data through API (ExpressJS) (ReactJS)?

Question

So basically I have a login I made that sends post data everytime a user presses the login button

sendLogin(e){
    e.preventDefault();
    fetch('/users', {
      method: 'POST',
      body: JSON.stringify({
        email: this.email.value,
        password: this.password.value
      }),
    }).then(function(response) {
      return response
    }).then(function(body) {
      console.log(body);
    });
  }
  render(){
    return (
      <form onSubmit={(event) => this.sendLogin(event)} class="asdf">
        <input type="text" placeholder="email" ref={(input) => { this.email = input}}/>
        <input type="password" placeholder="password" ref={(input) => { this.password = input }}/>
        <input type="submit" placeholder="submit"/>
      </form>
    )
  }

And in my express server.js code, I have it setup to console log the data we get

app.post('/users', function(req, res) {
    var user = req.body;
    res.end('Success');
    console.log('GOT A REQUEST');
    console.log(user);
})

The console.log(user) part isn't working at all, and in the client code the console.log(body); part also doesn't work at all. Any idea on how to fix this up?

EDIT: THEY BOTH COME UP AS UNDEFINED

Also when I changed return response to return response.json it gives me this error

Uncaught (in promise) SyntaxError: Unexpected token S in JSON at position 0
Promise rejected (async)

Vivek Doshi · Accepted Answer · 2017-12-04 04:12:23Z

1

The console.log(user) part isn't working at all, and in the client code the console.log(body); part also doesn't work at all. Any idea on how to fix this up?

That's becuase of sequence of execution :

Change this :

res.end('Success');
console.log('GOT A REQUEST');
console.log(user);

To :

console.log('GOT A REQUEST');
console.log(user);
res.end('Success');

Uncaught (in promise) SyntaxError: Unexpected token S in JSON at position 0 Promise rejected (async)

Reason for this error is res.end('Success'); , you are sending String in response instead of JSON , try res.end({data : logged_in_user_data});.

NOTE : If you need to respond with data, instead use methods such as res.send() and res.json().

edited Dec 4, 2017 at 4:12

answered Dec 4, 2017 at 4:01

Vivek Doshi

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6 Comments

adriam Over a year ago

It still gives me undefined and also Unhandled Rejection (SyntaxError): Unexpected end of JSON input and it shows response.json() as the error in the react.js code

Vivek Doshi Over a year ago

try res.end({status : 'success'}); from node side

adriam Over a year ago

I tried both that and res.end({data : logged_in_user_data}); but neither have been working. It keeps saying that return response.json(); is an error in the JS code

Vivek Doshi Over a year ago

Try to use res.json({status : 'success'});

adriam Over a year ago

So res.json({status : 'success'}); works, it comes up in the javascript console on the browser. The problem is on the nodejs console.log(user); still comes up as undefined

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