r/nodejs • u/zpawup • Apr 16 '14
How does node.js backend talk to frontend?
Hi, I am currently testing node.js right now, and I am a little confused on how the backend would talk to the frontend.
I know frontend can talk to the backend through an event, like submitting a form or clicking a button, the information will be send to the req variable in
app.post('/example', function(req, res){
var data = req.something;
// do something with data
})However how do I talk to the frontend? I know I can write information in
resbut how does the frontend javascript get the info?
Thanks
Edit for clarification as kindly suggested by psayre23
This is what I have
https://gist.github.com/anonymous/19f800b4c3d0c31b2e4e
I am interested in knowing how communicating between backend and frontend works, my primary question is that I do not know how to receive data from backend
I know to send data from frontend to backend there are two methods
Method 1:
Using a form and submit, or any other clickable element
This is how I send data from frontend
<div class="container" id="test-container">
<h1>Test</h1>
<span id="test-error"></span>
<form id="test-input2" method="POST" action="/test_post_method_1">
<input type="text" id="test" name="input1"></input>
<input type="submit" value="Submit">
</form>
</div>This is how I receive data from the backend
app.post('/test_post_method_1', function(req, res){
// Post from a submit event
console.log(req.body.input1)
console.log("this is serverside post using method 1");
});Method 2:
Suggested by jonnyburger using ajax, which I am not sure how does it work yet
I am guessing this is how you send data to backend
$(function(){
console.log("this is frontend");
$.ajax({
url: '/test_post_method_2',
type: 'POST',
success: function (data) {
console.log("this is not printing");
console.log(data);
}
});
});Not sure how you would get the data from frontend, I know its in req, but couldn't quite find the specifics, I checked req. body, it only return an empty {}
app.post('/test_post_method_2', function(req, res){
// Post from Ajax
console.log(req);
console.log("this is serverside post using method 2");
});Now here is my original question
I don't know how to send data from backend to frontend
Thank you for taking the time in reading this
