res.success back to frontend from a Node.Js/Express app

Question

I'm using AJAX in my app and at the frontend I have

$.post('/post', $("#submitform").serialize())
                .done(function(res) {
                    //3. Receive the server response, no need to emit an event
                    if (res.success) {
                        //4. Show the updated text
                        console.log('success');
                    }
                    else {
                        alert(res.error);
                    }})
                .fail(function(res) {
                    alert("Server Error: " + res.status + " " + res.statusText);
                });



        return false;
});

I'm sending back from my Node.Js/Express app route:

res.send(statement);

However, res.success doesn't get triggered and instead I go into alert(res.error) although the process performs fine at the backend.

What am I doing wrong? Shall I send something else from the backend of my app, like res.success?

Thank you!

Answer 1

Since, you are using ExpressJS with NodeJS on your server, you can send a error status code with the server when the HTTP request is not correct:

res.status(400).send('Bad Request')

In your client script which use the jQuery Deferred Object:

• deferred.done() is triggered when your HTTP request is a success;
• deferred.fail() is triggered if there is a client or server error;

So you should use as your code:

$.post('/post', $("#submitform").serialize())
    .done(function(res) {
        // Receive the successful server response
        console.log('success');
    })
    .fail(function(res) {
        // Receive the error server response
        alert("Error: " + res.status + " " + res.statusText);
    });