var user = 'user';
var pass = 'pass';
var myURL = 'https://project.MYDOMAIN.com:8444/rest/api/2/issue/createmeta?projectKeys=POLEX&issuetypeNames=Task&expand=projects.issuetypes.fields';

/*
var jiraAPI = "";
$.getJSON( jiraAPI, {
    format: "json"
})
.done(function( data ) {
    arr = $.map(data, function(el) { return el; })
});
*/

function loadJSON(path, success, error) {
    var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function() {
        if (xhr.readyState === XMLHttpRequest.DONE) {
            if(xhr.status === 200) {
                if(success)
                    success(JSON.parse(xhr.responseText));
            }
            else {
                if(error)
                    error(xhr);
            }
        }
    };
    xhr.open('GET', path, true);
    xhr.setRequestHeader('Authorization', 'Basic ' + btoa(user + ":" + pass));
    xhr.send();
}


loadJSON(
    myURL,
    function(data) { console.log(data); },
    function(xhr) { console.error(xhr); }
);


$("#myDIV").click(function() {
    $.ajax({
        url: myURL,
        username: user,
        password: pass,
        type: 'GET',
        //type: 'POST',
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        xhrFields: {
            withCredentials: true
        },
        beforeSend: function(xhr) {
            xhr.setRequestHeader('Authorization', 'Basic ' + btoa(user + ":" + pass));
            console.log("start");
        },
        success: function() {
            //arr = $.map(data, function(el) { return el; });
            console.log("done");
        },
        /*
        done: function() {
            //arr = $.map(data, function(el) { return el; });
            console.log("finish");
        }
        */
    });
});