Problem
I was trying to submit data from a web page to a back-end API in PHP using jQuery’s AJAX (ie. $.ajax()).
But the $_POST variable in PHP didn’t contain the values I was posting.
Solution
The problem is I was encoding the POST body data the wrong way in JavaScript.
I was using JSON.stringify(data), where “data” is a JavaScript object or array.
What I needed to do what manually create a string of key1=value1&key2=value2&keyN=valueN pairs.
Example Code from my submit function:
//sendData = JSON.stringify(data); //<-- This doesn't work ...
// ... but this does.
sendData = "";
for (var key in data)
{
if (sendData != "") sendData = sendData + "&";
sendData = sendData + key + "=" + data[key];
}
var ajaxRequest = {
url: url,
type: "POST",
data: sendData,
dataType: dataType,
success: function(data, textStatus, jqXHR) { successCallback(data, textStatus, jqXHR ); },
error: function(jqXHR, textStatus, errorThrown) { errorCallback(data, textStatus, errorThrown); }
};
$.ajax(ajaxRequest);
What I searched for (which didn’t help much):
Search “$_POST empty from jquery”: https://duckduckgo.com/?q=%24_POST+empty+from+jquery&atb=v147-1&ia=web
https://stackoverflow.com/questions/1650516/jquery-ajax-method-post-but-post-empty
https://stackoverflow.com/questions/16360008/jquery-post-post-empty
https://stackoverflow.com/questions/1650516/jquery-ajax-method-post-but-post-empty/49948834#49948834