Error in Sending JSOn DATA to PHP through Ajax [duplicate] - php

Question

This question already has answers here:
Reading JSON POST using PHP
(3 answers)
Closed 7 years ago.
I'm able to send JSON Data to server through Ajax as i can see it in params of My Browser Developer Tool => Network but i get No Response Even if try to Print $_REQUEST, $_POST I get just the Cookie Value but not data which I have send
I'm Following From MDN https://developer.mozilla.org/en-US/docs/AJAX/Getting_Started
Here what I've tried, I'm trying to send data to server without jQuery Ajax method
After I do this on Server side
echo json_encode($_REQUEST['msgData']);
I get
Notice: Undefined index: msgData in
/path/to/url/ABC/controller/msgNotify.php
on line 24 null
jQuery(document).ready(function(){
jQuery('#msgNotify').on('click',function(){
alert("He");
var data={};
data['info']='msgNotify';
data['username']=username;
var msgData={'msgData':data};
makeRequest(msgData,'../controller/msgNotify.php');
});
});
function makeRequest(data,url) {
if (window.XMLHttpRequest) { // Mozilla, Safari, ...
var httpRequest = new XMLHttpRequest();
} else if (window.ActiveXObject) { // IE
try {
httpRequest = new ActiveXObject("Msxml2.XMLHTTP");
}
catch (e) {
try {
httpRequest = new ActiveXObject("Microsoft.XMLHTTP");
}
catch (e) {}
}
}
if (!httpRequest) {
alert('Giving up :( Cannot create an XMLHTTP instance');
return false;
}
httpRequest.open('POST', url);
httpRequest.setRequestHeader('Content-Type', 'application/json; charset=UTF-8');
httpRequest.onload = alertContents;
httpRequest.send(JSON.stringify(data));
}
function alertContents() {
try{
if (httpRequest.status === 200) {
alert(httpRequest.responseText);
} else {
alert('There was a problem with the request.');
}
}catch(e){
alert('Caught Exception: ' + e.description);
}
}
SERVER SIDE "../controller/msgNotify.php"
echo json_encode($_REQUEST['msgData']);
exit;

Answer 1

Without changing the way you are doing your POST (the JSON is in the body of the http request), you should read as follows
// extract from my Servlet class :
$content = file_get_contents('php://input');
$ary = json_decode($content , true); // prefer decoding to associative array
if ($content && !$ary) {
self::logResponseStatus('Received malformed JSON', api_request_status::MALFORMED_REQUEST);
return false;
}
$command = $ary['command'];
$apiKey = $ary['apiKey'];
// ... etc

Answer 2

You are sending your data as JSON string without key for getting this parametar in your request.
You could try with this:
httpRequest.send("msgData=" + JSON.stringify(data));
Your msgData will be key to getting your object {'msgData':data}. Since it's already a JSON string you don't need to use json_encode in php. If you want only to display "data" from received json you can use
$data = json_decode( $_REQUEST['msgData'] )
echo json_encode($data["msgData"]);