Node.js can't handle my client code that performs something similar to jQuery/Zepto XHR pattern below:
$.ajax({
type: 'POST',
url: '/someUrl',
success: function(response) {
$.ajax({ // ... do another XHR
I've done this (initiating an XHR request within another XHR request) pattern before within other frameworks. I've read about Node.js Error: Can't set headers after they are sent and how the event-based model of Node.js server works. In other words, the first XHR request hasn't called res.end() so when the second XHR request is called Node.js complains (in a continuous loop btw).
My questions are: Would anyone be able to recommend an alternative pattern to chaining XHR requests client-side? Is there something I can do Node.js server-side to keep the existing client-side pattern?
Update Based On Accepted Answer
The mistake is certainly in my own server side code. A simple validation function was throwing an error but upon catching it, only res.end() was called. For some reason the assumption I had was calling res.end() would immediately stop the execution of the function. In this case, inserting a 'return' stops execution immediately after sending the JSON message to the client.
if (_.isEmpty(req.body)) {
res.end(JSON.stringify({'Error':'POST required'}));
// suppose 'return' is needed here as well
return
} else {
try {
if (_.has(req.body, 'id')) {
id = parseInt(req.body['id']);
} else {
throw {'Error':'Missing param in req.body'};
} // end if
} catch(err) {
res.end(JSON.stringify({'Error':'Missing key(s)','Keys':_.keys(req.body)}));
// without a return here, the code below this 'do some more work' would
// be executed
return
} // end else
// do some more work
// without the above 'return''s the code would
// a) make a database call
// b) call res.end() again!!! <-- bad.
