How to send a custom http status message in node / express?

Question

My node.js app is modeled like the express/examples/mvc app.

In a controller action I want to spit out a HTTP 400 status with a custom http message. By default the

Answer 1

At server side(Express middleware):

if(err) return res.status(500).end('User already exists.');

Handle at Client side

Angular:-

$http().....
.error(function(data, status) {
  console.error('Repos error', status, data);//"Repos error" 500 "User already exists."
});

jQuery:-

$.ajax({
    type: "post",
    url: url,
    success: function (data, text) {
    },
    error: function (request, status, error) {
        alert(request.responseText);
    }
});

Answer 2

One elegant way to handle custom errors like this in express is:

function errorHandler(err, req, res, next) {
  var code = err.code;
  var message = err.message;
  res.writeHead(code, message, {'content-type' : 'text/plain'});
  res.end(message);
}

(you can also use express' built-in express.errorHandler for this)

Then in your middleware, before your routes:

app.use(errorHandler);

Then where you want to create the error 'Current password does not match':

function checkPassword(req, res, next) {
  // check password, fails:
  var err = new Error('Current password does not match');
  err.code = 400;
  // forward control on to the next registered error handler:
  return next(err);
}

Answer 3

You can use it like this

return res.status(400).json({'error':'User already exists.'});