Ajax helper

gistfile1.txt

A17.Helpers.ajax_request = function(settings) {
  /*

  # A17.Helpers.ajax_request
  * v.1

  ## description
  Performs ajax requests

  ## requires
  * A17.Helpers.turn_object_to_queryString

  ## parameters
  settings object - required:
  * url - required - url to send request to
  * type - required - HTTP method to use ("POST", "GET", "PUT")
  * data - optional - data object turned into a query string on the request
  * requestHeaders - optional - an array of request header objects with header/value pairs eg:  [{ header: "X-Requested-With", value: "XMLHttpRequest" }]
  * onSuccess - optional - function to run on request success, returns the responseText, in whatever format that is
  * onError - optional - function to run on request error, returns the responseText, if there is any, in whatever format that is

  ## returns
  * nothing

  ## example usage:
  A17.Helpers.ajax_request({
    url: '/form-post.php',
    type: "POST",
    data: {
      param1: "param1value",
      param2: "param2value"
    },
    requestHeaders: [
      {
        header: "Content-Type",
        value: "application/x-www-form-urlencoded; charset=UTF-8"
      },
      {
        header: "X-Requested-With",
        value: "XMLHttpRequest"
      }
    ],
    onSuccess: function(data){
      el.innerHTML = data;
    },
    onError: function(data){
      alert(data);
    }
  });
  */

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

  options.query_string = "";
  if (options.data !== undefined) {
    if (A17.Helpers.turn_object_to_queryString) {
      options.query_string = A17.Helpers.turn_object_to_queryString(options.data);
    } else {
      console.log("Missing: A17.Helpers.turn_object_to_queryString");
    }
  }

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

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

  if (options.requestHeaders !== undefined && options.requestHeaders.length > 0) {
    for (var i = 0; i < options.requestHeaders.length; i++) {
      var header = options.requestHeaders[i].header;
      var value = options.requestHeaders[i].value;
      if (header !== undefined && value !== undefined) {
        request.setRequestHeader(header, value);
      }
    }
  }

  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();
};