What is the vanilla JS version of Jquery's $.getJSON

Question

I need to build a project to get into a JS bootcamp I am applying for. They tell me I may only use vanilla JS, specifically that frameworks and Jquery are not permitted. Up to

Answer 1

Here is a vanilla JS version of Ajax

var $ajax = (function(){
    var that = {};
    that.send = function(url, options) {
        var on_success = options.onSuccess || function(){},
            on_error   = options.onError   || function(){},
            on_timeout = options.onTimeout || function(){},
            timeout    = options.timeout   || 10000; // ms

        var xmlhttp = new XMLHttpRequest();
        xmlhttp.onreadystatechange = function() {
            if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                //console.log('responseText:' + xmlhttp.responseText);
                try {
                    var data = JSON.parse(xmlhttp.responseText);
                } catch(err) {
                    console.log(err.message + " in " + xmlhttp.responseText);
                    return;
                }
                on_success(data);
            }else{
                if(xmlhttp.readyState == 4){
                    on_error();
                }
            }
        };
        xmlhttp.timeout = timeout;
        xmlhttp.ontimeout = function () { 
            on_timeout();
        }
        xmlhttp.open("GET", url, true);
        xmlhttp.send();
    }
    return that;
})();

Example:

$ajax.send("someUrl.com", {
    onSuccess: function(data){
        console.log("success",data);
    },
    onError: function(){
        console.log("Error");
    },
    onTimeout: function(){
        console.log("Timeout");
    },
    timeout: 10000
});