JAVASCRIPT

javascript promise with ajax

function doTheThing() {
  $.ajax({
    url: window.location.href,
    type: 'POST',
    data: {
      key: 'value',
    },
    success: function (data) {
      console.log(data)
    },
    error: function (error) {
      console.log(error)
    },
  })
}

javascript promise with ajax

doTheThing()
doSomethingElse()

javascript pure ajax promise

function getRequest(url) {
    return makeRequest('GET', url);
}

function postRequest(url, data) {
    return makeRequest('POST', url, data);
}

function makeRequest(method, url, data) {
    return new Promise(
        function(resolve, reject) {
            var http = new XMLHttpRequest();
            http.open(method, url);
            http.onload = function() {
                if (this.status >= 200 && this.status < 300) {
                    var response = http.response;
                    try {
                        response = JSON.parse(response);
                        resolve(response);
                    } catch (error) {
                        reject({
                            status: this.status,
                            statusText: error
                        });
                    }

                } else {
                    reject({
                        status: this.status,
                        statusText: http.statusText
                    });
                }
            };
            http.onerror = function() {
                reject({
                    status: this.status,
                    statusText: http.statusText
                });
            };

            if (method === 'POST') {
                data = data || new FormData();
                http.send((data));
            } else http.send();
        }
    );
}