Autocomplete

var ajax = new XMLHttpRequest();

ajax.open("GET", "https://restcountries.eu/rest/v1/lang/fr", true); // Dummy json

ajax.onload = function() {
    var list = JSON.parse(ajax.responseText).map(function(i) { return i.name; });
    Awesomplete.$$(".vgr-form-field__input--autocomplete").forEach(function (input) {
        new Awesomplete(input,{
            list: list,
            minChars: 2,
            maxItems: 5
        });
        window.addEventListener("awesomplete-selectcomplete", function(e){
          console.log("Submit");
        }, false);
    });
};
ajax.send();

/**
 * Simple, lightweight, usable local autocomplete library for modern browsers
 * Because there weren’t enough autocomplete scripts in the world? Because I’m completely insane and have NIH syndrome? Probably both. :P
 * @author Lea Verou http://leaverou.github.io/awesomplete
 * MIT license
 */

(function () {

var _ = function (input, o) {
  var me = this;

  // Setup

  this.isOpened = false;

  this.input = $(input);
  this.input.setAttribute("autocomplete", "off");
  this.input.setAttribute("aria-autocomplete", "list");

  o = o || {};

  configure(this, {
    minChars: 2,
    maxItems: 10,
    autoFirst: false,
    data: _.DATA,
    filter: _.FILTER_CONTAINS,
    sort: _.SORT_BYLENGTH,
    item: _.ITEM,
    replace: _.REPLACE
  }, o);

  this.index = -1;

  // Create necessary elements

  this.container = $.create("div", {
    className: "awesomplete",
    around: input
  });

  this.ul = $.create("ul", {
    hidden: "hidden",
    inside: this.container
  });

  this.status = $.create("span", {
    className: "vgr-visually-hidden",
    role: "status",
    "aria-live": "assertive",
    "aria-relevant": "additions",
    inside: this.container
  });

  // Bind events

  $.bind(this.input, {
    "input": this.evaluate.bind(this),
    "blur": this.close.bind(this, { reason: "blur" }),
    "keydown": function(evt) {
      var c = evt.keyCode;

      // If the dropdown `ul` is in view, then act on keydown for the following keys:
      // Enter / Esc / Up / Down
      if(me.opened) {
        if (c === 13 && me.selected) { // Enter
          evt.preventDefault();
          me.select();
        }
        else if (c === 27) { // Esc
          me.close({ reason: "esc" });
        }
        else if (c === 38 || c === 40) { // Down/Up arrow
          evt.preventDefault();
          me[c === 38? "previous" : "next"]();
        }
      }
    }
  });

  $.bind(this.input.form, {"submit": this.close.bind(this, { reason: "submit" })});

  $.bind(this.ul, {"mousedown": function(evt) {
    var li = evt.target;

    if (li !== this) {

      while (li && !/li/i.test(li.nodeName)) {
        li = li.parentNode;
      }

      if (li && evt.button === 0) {  // Only select on left click
        evt.preventDefault();
        me.select(li, evt.target);
      }
    }
  }});

  if (this.input.hasAttribute("list")) {
    this.list = "#" + this.input.getAttribute("list");
    this.input.removeAttribute("list");
  }
  else {
    this.list = this.input.getAttribute("data-list") || o.list || [];
  }

  _.all.push(this);
};

_.prototype = {
  set list(list) {
    if (Array.isArray(list)) {
      this._list = list;
    }
    else if (typeof list === "string" && list.indexOf(",") > -1) {
        this._list = list.split(/\s*,\s*/);
    }
    else { // Element or CSS selector
      list = $(list);

      if (list && list.children) {
        var items = [];
        slice.apply(list.children).forEach(function (el) {
          if (!el.disabled) {
            var text = el.textContent.trim();
            var value = el.value || text;
            var label = el.label || text;
            if (value !== "") {
              items.push({ label: label, value: value });
            }
          }
        });
        this._list = items;
      }
    }

    if (document.activeElement === this.input) {
      this.evaluate();
    }
  },

  get selected() {
    return this.index > -1;
  },

  get opened() {
    return this.isOpened;
  },

  close: function (o) {
    if (!this.opened) {
      return;
    }

    this.ul.setAttribute("hidden", "");
    this.isOpened = false;
    this.index = -1;

    $.fire(this.input, "awesomplete-close", o || {});
  },

  open: function () {
    this.ul.removeAttribute("hidden");
    this.isOpened = true;

    if (this.autoFirst && this.index === -1) {
      this.goto(0);
    }

    $.fire(this.input, "awesomplete-open");
  },

  next: function () {
    var count = this.ul.children.length;
    this.goto(this.index < count - 1 ? this.index + 1 : (count ? 0 : -1) );
  },

  previous: function () {
    var count = this.ul.children.length;
    var pos = this.index - 1;

    this.goto(this.selected && pos !== -1 ? pos : count - 1);
  },

  // Should not be used, highlights specific item without any checks!
  goto: function (i) {
    var lis = this.ul.children;

    if (this.selected) {
      lis[this.index].setAttribute("aria-selected", "false");
    }

    this.index = i;

    if (i > -1 && lis.length > 0) {
      lis[i].setAttribute("aria-selected", "true");
      this.status.textContent = lis[i].textContent;

      $.fire(this.input, "awesomplete-highlight", {
        text: this.suggestions[this.index]
      });
    }
  },

  select: function (selected, origin) {
    if (selected) {
      this.index = $.siblingIndex(selected);
    } else {
      selected = this.ul.children[this.index];
    }

    if (selected) {
      var suggestion = this.suggestions[this.index];

      var allowed = $.fire(this.input, "awesomplete-select", {
        text: suggestion,
        origin: origin || selected
      });

      if (allowed) {
        this.replace(suggestion);
        this.close({ reason: "select" });
        $.fire(this.input, "awesomplete-selectcomplete", {
          text: suggestion
        });
      }
    }
  },

  evaluate: function() {
    var me = this;
    var value = this.input.value;

    if (value.length >= this.minChars && this._list.length > 0) {
      this.index = -1;
      // Populate list with options that match
      this.ul.innerHTML = "";

      this.suggestions = this._list
        .map(function(item) {
          return new Suggestion(me.data(item, value));
        })
        .filter(function(item) {
          return me.filter(item, value);
        })
        .sort(this.sort)
        .slice(0, this.maxItems);

      this.suggestions.forEach(function(text) {
          me.ul.appendChild(me.item(text, value));
        });

      if (this.ul.children.length === 0) {
        this.close({ reason: "nomatches" });
      } else {
        this.open();
      }
    }
    else {
      this.close({ reason: "nomatches" });
    }
  }
};

// Static methods/properties

_.all = [];

_.FILTER_CONTAINS = function (text, input) {
  return RegExp($.regExpEscape(input.trim()), "i").test(text);
};

_.FILTER_STARTSWITH = function (text, input) {
  return RegExp("^" + $.regExpEscape(input.trim()), "i").test(text);
};

_.SORT_BYLENGTH = function (a, b) {
  if (a.length !== b.length) {
    return a.length - b.length;
  }

  return a < b? -1 : 1;
};

_.ITEM = function (text, input) {
  var html = input.trim() === '' ? text : text.replace(RegExp($.regExpEscape(input.trim()), "gi"), "<mark>$&</mark>");
  return $.create("li", {
    innerHTML: html,
    "aria-selected": "false"
  });
};

_.REPLACE = function (text) {
  this.input.value = text.value;
};

_.DATA = function (item/*, input*/) { return item; };

// Private functions

function Suggestion(data) {
  var o = Array.isArray(data)
    ? { label: data[0], value: data[1] }
    : typeof data === "object" && "label" in data && "value" in data ? data : { label: data, value: data };

  this.label = o.label || o.value;
  this.value = o.value;
}
Object.defineProperty(Suggestion.prototype = Object.create(String.prototype), "length", {
  get: function() { return this.label.length; }
});
Suggestion.prototype.toString = Suggestion.prototype.valueOf = function () {
  return "" + this.label;
};

function configure(instance, properties, o) {
  for (var i in properties) {
    var initial = properties[i],
        attrValue = instance.input.getAttribute("data-" + i.toLowerCase());

    if (typeof initial === "number") {
      instance[i] = parseInt(attrValue);
    }
    else if (initial === false) { // Boolean options must be false by default anyway
      instance[i] = attrValue !== null;
    }
    else if (initial instanceof Function) {
      instance[i] = null;
    }
    else {
      instance[i] = attrValue;
    }

    if (!instance[i] && instance[i] !== 0) {
      instance[i] = (i in o)? o[i] : initial;
    }
  }
}

// Helpers

var slice = Array.prototype.slice;

function $(expr, con) {
  return typeof expr === "string"? (con || document).querySelector(expr) : expr || null;
}

function $$(expr, con) {
  return slice.call((con || document).querySelectorAll(expr));
}

$.create = function(tag, o) {
  var element = document.createElement(tag);

  for (var i in o) {
    var val = o[i];

    if (i === "inside") {
      $(val).appendChild(element);
    }
    else if (i === "around") {
      var ref = $(val);
      ref.parentNode.insertBefore(element, ref);
      element.appendChild(ref);
    }
    else if (i in element) {
      element[i] = val;
    }
    else {
      element.setAttribute(i, val);
    }
  }

  return element;
};

$.bind = function(element, o) {
  if (element) {
    for (var event in o) {
      var callback = o[event];

      event.split(/\s+/).forEach(function (event) {
        element.addEventListener(event, callback);
      });
    }
  }
};

$.fire = function(target, type, properties) {
  var evt = document.createEvent("HTMLEvents");

  evt.initEvent(type, true, true );

  for (var j in properties) {
    evt[j] = properties[j];
  }

  return target.dispatchEvent(evt);
};

$.regExpEscape = function (s) {
  return s.replace(/[-\\^$*+?.()|[\]{}]/g, "\\$&");
};

$.siblingIndex = function (el) {
  /* eslint-disable no-cond-assign */
  for (var i = 0; el = el.previousElementSibling; i++);
  return i;
};

// Initialization

function init() {
  $$("input.awesomplete").forEach(function (input) {
    new _(input);
  });
}

// Are we in a browser? Check for Document constructor
if (typeof Document !== "undefined") {
  // DOM already loaded?
  if (document.readyState !== "loading") {
    init();
  }
  else {
    // Wait for it
    document.addEventListener("DOMContentLoaded", init);
  }
}

_.$ = $;
_.$$ = $$;

// Make sure to export Awesomplete on self when in a browser
if (typeof self !== "undefined") {
  self.Awesomplete = _;
}

// Expose Awesomplete as a CJS module
if (typeof module === "object" && module.exports) {
  module.exports = _;
}

return _;

}());