Ajax helper

ajax_request.js

charlierose.Helpers.ajax_request = function(options) {

  /*
  where options is an object:
  charlierose.Helpers.ajax_request({
    url: '/',
    type: "POST",
    data: { param1: "param1value", param2: "param2value" },
    requestHeader: { header: "Content-Type", value: "application/x-www-form-urlencoded; charset=UTF-8" },
    onSuccess: function(data){

    },
    onError: function(){
    }
  });

  data,requestHeader,onSuccess and onError are optional
  onSuccess returns the responseText, in whatever format that is.
  */

  var options = options;
  var request = new XMLHttpRequest();

  options.query_string = "";
  if (options.data !== undefined) {
    options.query_string = charlierose.Helpers.turn_object_to_queryString(options.data);
  }

  request.open(options.type, options.url+options.query_string, true);

  if (options.type === "POST" && options.requestHeader === undefined) {
    request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
  }

  if (options.requestHeader !== undefined && Object.getOwnPropertyNames(options.requestHeader).length > 0) {
    request.setRequestHeader(options.requestHeader.header, options.requestHeader.value);
  }

  // Add a header used by Rails to detect ajax requests
  request.setRequestHeader('X-Requested-With', 'XMLHttpRequest');

  request.onload = function() {
    if (request.status >= 200 && request.status < 400){
      // Success!
      if ((typeof options.onSuccess).toLowerCase() === "function") {
        options.onSuccess.call(this,request.responseText);
      }
    } else {
      console.log("We reached our target server, but it returned an error: "+request.statusText);
      if ((typeof options.onError).toLowerCase() === "function") {
        options.onError.call(this,request.responseText);
      }
    }
  };

  request.onerror = function() {
    console.log("There was a connection error of some sort");
    if ((typeof options.onError).toLowerCase() === "function") {
      options.onError.call();
    }
  };

  request.send();
};

same_uage.js

charlierose.Helpers.ajax_request({
  url: request_url,
  requestHeader: { header: "X-CSRF-Token", value: token },
  type: "GET",
  onSuccess: function(data){
    // Add new videos
    document.getElementById(container.attr("data-target")).innerHTML += data;
    // tell the document about it
    document.trigger("more_videos_added");
    //
    container.removeClass("btn-loading");
  },
  onError: function(){
    // on error
    container.parentNode.removeChild(container);
  }
});

turn_object_to_queryString

charlierose.Helpers.turn_object_to_queryString = function(obj) {

  var query_string = "";
  var count = 0;

  if (Object.getOwnPropertyNames(obj).length > 0) {
    query_string = "?";
    for (key in obj) {
      if (!obj.hasOwnProperty(key)) {
        continue;
      }
      query_string += ((count > 0) ? "&" : "") + key + "=" + encodeURIComponent(obj[key]).replace(/[!'()]/g, escape).replace(/\*/g, "%2A");
      count++;
    }
  }

  return query_string;
};