This is a fork of Bootstrap Typeahead that adds minimal but powerful extensions. For example, process typeahead list asynchronously and return objects This is an adoption of gudburgurs gist to Version 2.2.2 of Bootstrap. See https://gist.github.com/1866577

bootstrap-typeahead.js

/* =============================================================
 * bootstrap-typeahead.js v2.2.2
 * http://twitter.github.com/bootstrap/javascript.html#typeahead
 * =============================================================
 * Copyright 2012 Twitter, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * ============================================================ */


!function($){

  "use strict"; // jshint ;_;


 /* TYPEAHEAD PUBLIC CLASS DEFINITION
  * ================================= */

  var Typeahead = function (element, options) {
    this.$element = $(element)
    this.options = $.extend({}, $.fn.typeahead.defaults, options)
    this.matcher = this.options.matcher || this.matcher
    this.sorter = this.options.sorter || this.sorter
    this.highlighter = this.options.highlighter || this.highlighter
    this.updater = this.options.updater || this.updater
    this.source = this.options.source
    this.$menu = $(this.options.menu)
    this.onselect = this.options.onselect
    this.string = true
    this.shown = false
    this.listen()
  }

  Typeahead.prototype = {

    constructor: Typeahead

  , select: function () {
      var val = this.$menu.find('.active').attr('data-value')
        , text

      if (!this.strings) text = val[this.options.property]
      else text = val

      this.$element
        .val(this.updater(text))
        .change()

      if (typeof this.onselect == "function")
        this.onselect(val)

      return this.hide()
    }

  , updater: function (item) {
      return item
    }

  , show: function () {
      var pos = $.extend({}, this.$element.position(), {
        height: this.$element[0].offsetHeight
      })

      this.$menu
        .insertAfter(this.$element)
        .css({
          top: pos.top + pos.height
        , left: pos.left
        })
        .show()

      this.shown = true
      return this
    }

  , hide: function () {
      this.$menu.hide()
      this.shown = false
      return this
    }

  , lookup: function (event) {
      var items

      this.query = this.$element.val()

      if (!this.query || this.query.length < this.options.minLength) {
        return this.shown ? this.hide() : this
      }

      items = $.isFunction(this.source) ? this.source(this.query, $.proxy(this.process, this)) : this.source

      return items ? this.process(items) : this
    }

  , process: function (items) {
      var that = this

      items = $.grep(items, function (item) {
        if (!that.strings)
          item = item[that.options.property]
        return that.matcher(item)
      })

      items = this.sorter(items)

      if (!items.length) {
        return this.shown ? this.hide() : this
      }

      return this.render(items.slice(0, this.options.items)).show()
    }

  , matcher: function (item) {
      return ~item.toLowerCase().indexOf(this.query.toLowerCase())
    }

  , sorter: function (items) {
      var beginswith = []
        , caseSensitive = []
        , caseInsensitive = []
        , item
        , sortby

      while (item = items.shift()) {
        if (this.strings) sortby = item
          else sortby = item[this.options.property]
        if (!sortby.toLowerCase().indexOf(this.query.toLowerCase())) beginswith.push(item)
        else if (~sortby.indexOf(this.query)) caseSensitive.push(item)
        else caseInsensitive.push(item)
      }

      return beginswith.concat(caseSensitive, caseInsensitive)
    }

  , highlighter: function (item) {
      var query = this.query.replace(/[\-\[\]{}()*+?.,\\\^$|#\s]/g, '\\$&')
      return item.replace(new RegExp('(' + query + ')', 'ig'), function ($1, match) {
        return '<strong>' + match + '</strong>'
      })
    }

  , render: function (items) {
      var that = this

      items = $(items).map(function (i, item) {
        i = $(that.options.item).attr('data-value', JSON.stringify(item))
        if (!that.strings)
          item = item[that.options.property]
        i.find('a').html(that.highlighter(item))
        return i[0]
      })

      items.first().addClass('active')
      this.$menu.html(items)
      return this
    }

  , next: function (event) {
      var active = this.$menu.find('.active').removeClass('active')
        , next = active.next()

      if (!next.length) {
        next = $(this.$menu.find('li')[0])
      }

      next.addClass('active')
    }

  , prev: function (event) {
      var active = this.$menu.find('.active').removeClass('active')
        , prev = active.prev()

      if (!prev.length) {
        prev = this.$menu.find('li').last()
      }

      prev.addClass('active')
    }

  , listen: function () {
      this.$element
        .on('blur',     $.proxy(this.blur, this))
        .on('keypress', $.proxy(this.keypress, this))
        .on('keyup',    $.proxy(this.keyup, this))

      if (this.eventSupported('keydown')) {
        this.$element.on('keydown', $.proxy(this.keydown, this))
      }

      this.$menu
        .on('click', $.proxy(this.click, this))
        .on('mouseenter', 'li', $.proxy(this.mouseenter, this))
    }

  , eventSupported: function(eventName) {
      var isSupported = eventName in this.$element
      if (!isSupported) {
        this.$element.setAttribute(eventName, 'return;')
        isSupported = typeof this.$element[eventName] === 'function'
      }
      return isSupported
    }

  , move: function (e) {
      if (!this.shown) return

      switch(e.keyCode) {
        case 9: // tab
        case 13: // enter
        case 27: // escape
          e.preventDefault()
          break

        case 38: // up arrow
          e.preventDefault()
          this.prev()
          break

        case 40: // down arrow
          e.preventDefault()
          this.next()
          break
      }

      e.stopPropagation()
    }

  , keydown: function (e) {
      this.suppressKeyPressRepeat = ~$.inArray(e.keyCode, [40,38,9,13,27])
      this.move(e)
    }

  , keypress: function (e) {
      if (this.suppressKeyPressRepeat) return
      this.move(e)
    }

  , keyup: function (e) {
      switch(e.keyCode) {
        case 40: // down arrow
        case 38: // up arrow
        case 16: // shift
        case 17: // ctrl
        case 18: // alt
          break

        case 9: // tab
        case 13: // enter
          if (!this.shown) return
          this.select()
          break

        case 27: // escape
          if (!this.shown) return
          this.hide()
          break

        default:
          this.lookup()
      }

      e.stopPropagation()
      e.preventDefault()
  }

  , blur: function (e) {
      var that = this
      setTimeout(function () { that.hide() }, 150)
    }

  , click: function (e) {
      e.stopPropagation()
      e.preventDefault()
      this.select()
    }

  , mouseenter: function (e) {
      this.$menu.find('.active').removeClass('active')
      $(e.currentTarget).addClass('active')
    }

  }


  /* TYPEAHEAD PLUGIN DEFINITION
   * =========================== */

  var old = $.fn.typeahead

  $.fn.typeahead = function (option) {
    return this.each(function () {
      var $this = $(this)
        , data = $this.data('typeahead')
        , options = typeof option == 'object' && option
      if (!data) $this.data('typeahead', (data = new Typeahead(this, options)))
      if (typeof option == 'string') data[option]()
    })
  }

  $.fn.typeahead.defaults = {
    source: []
  , items: 8
  , menu: '<ul class="typeahead dropdown-menu"></ul>'
  , item: '<li><a href="#"></a></li>'
  , minLength: 1
  , onselect: null
  , property: 'value'
  }

  $.fn.typeahead.Constructor = Typeahead


 /* TYPEAHEAD NO CONFLICT
  * =================== */

  $.fn.typeahead.noConflict = function () {
    $.fn.typeahead = old
    return this
  }


 /* TYPEAHEAD DATA-API
  * ================== */

  $(document).on('focus.typeahead.data-api', '[data-provide="typeahead"]', function (e) {
    var $this = $(this)
    if ($this.data('typeahead')) return
    e.preventDefault()
    $this.typeahead($this.data())
  })

}(window.jQuery);

Any additional changes to do for v2.3.1?
Thanks