Basic XHR example

by Financial Modeling Prep

HTML

<input type="button" id="basicXHRButton" value="Try It">

JavaScript

document.getElementById("basicXHRButton").addEventListener("click", function() {
        // Loading the jQuery code
        request = new XMLHttpRequest();
        request.open("GET", "https://fmpcloud.io/api/v3/mutual-fund-holder/AAPL?apikey=demo", true);
         request.setRequestHeader("Authorization","test");
       request.setRequestHeader("Accept","*/*");
request.setRequestHeader("Access-Control-Request-Method"," GET");
request.setRequestHeader("Access-Control-Request-Headers"," access-control-allow-headers,access-control-allow-methods,access-control-allow-origin,access-control-max-age,authorization");
request.setRequestHeader("Origin"," https","//fiddle.jshell.net");
request.setRequestHeader("Sec-Fetch-Mode","cors");
request.setRequestHeader("Sec-Fetch-Site","cross-site");
request.setRequestHeader("Sec-Fetch-Dest","empty");
request.setRequestHeader("Referer","https//fiddle.jshell.net/");
request.setRequestHeader("User-Agent"," Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.121 Safari/537.36");
request.setRequestHeader("Accept-Encoding","gzip, deflate, br");
request.setRequestHeader("Accept-Language","en-US,en;q=0.9,fr;q=0.8");
        request.send(null);

        request.onreadystatechange = function() {
            if(request.readyState === 4) { // What does this even mean?
                if(request.status === 200) {
                    console.log(request.responseText);
                    alert("Done using XHR!");
                }
            }
        }
    });