Bootstrap's Typeahead plugin extended (AJAX functionality, comma-separated values, autowidth, and autoselect)

README.markdown

This is a fork of a fork of Bootstrap Typeahead that adds minimal but powerful extensions.

• Ability to disable autoselect of first matched element.
• Ability to automatically set the width of the dropdown to that of the text input.
• Ability to fetch source element via AJAX
• Ability to have a comma separated list of tags.

For the proper source, and other examples, please see the original gist.

Example showing off all the above features

  // This example is in Javascript, fetches a tag via AJAX and appends it to the comma separated list of tags
  $('#tags').typeahead({
    source: function(typeahead, query) {
      var term = $.trim(query.split(',').pop());
      if (term == '') return [];
      $.getJSON('/tags/typeahead.json' + '?', { term: term }, function(data) {
        typeahead.process(data);
      });
    }
  , onselect: function(item, previous_items) {
      terms = previous_items.split(',');
      terms.pop();
      terms.push(item);
      terms.push('');
      $.each(terms, function(idx, val) { terms[idx] = $.trim(val); });
      $('#tags').val(terms.join(', '));
    }
  // Matcher always returns true since there are multiple comma-seperated terms in the input box and the server ensures only matching terms are returned
  , matcher: function() { return true; }
  // Autoselect is disabled so that users can enter new tags
  , autoselect: false
  });

bootstrap-typeahead.js

/* =============================================================
 * bootstrap-typeahead.js v2.0.0
 * 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"

  var Typeahead = function ( element, options ) {
    this.$element = $(element)
    this.options = $.extend({}, $.fn.typeahead.defaults, options)
    this.matcher = this.options.matcher || this.matcher
    this.sorter = this.options.sorter || this.sorter
    this.highlighter = this.options.highlighter || this.highlighter
    this.$menu = $(this.options.menu).appendTo('body')
    this.source = this.options.source
    this.onselect = this.options.onselect
    this.autoselect = this.options.autoselect
    this.autowidth = this.options.autowidth
    this.strings = true
    this.shown = false
    this.listen()
  }

  Typeahead.prototype = {

    constructor: Typeahead

  , select: function () {
      var text, original_text;
      if (this.$menu.find('.active').length == 0) {
        var val = this.$element.val();
      }
      else {
        var val = JSON.parse(this.$menu.find('.active').attr('data-value'));
      }

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

      original_text = this.$element.val();
      this.$element.val(text)

      if (typeof this.onselect == "function")
          this.onselect(text, original_text, val)

      return this.hide()
    }

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

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

      this.$menu.show()
      this.shown = true
      return this
    }

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

  , lookup: function (event) {
      var that = this
        , items
        , q
        , value

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

      if (typeof this.source == "function") {
        value = this.source(this, this.query)
        if (value) this.process(value)
      } else {
        this.process(this.source)
      }
    }

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

      if (results.length && typeof results[0] != "string")
          this.strings = false

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

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

      items = $.grep(results, function (item) {
        if (!that.strings)
          item = item[that.options.property]
        if (that.matcher(item)) return 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) {
      return item.replace(new RegExp('(' + this.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]
      })

      if (that.autoselect) items.first().addClass('active')
      if (that.autowidth) this.$menu.width(this.$element.width());
      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 ($.browser.webkit || $.browser.msie) {
        this.$element.on('keydown', $.proxy(this.keypress, this))
      }

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

  , keyup: function (e) {
      e.stopPropagation()
      e.preventDefault()

      switch(e.keyCode) {
        case 40: // down arrow
        case 38: // up arrow
          break

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

        case 9: // tab
          var that = this
          e.stopPropagation()
          e.preventDefault()
          setTimeout(function () { that.hide() }, 150)
          break

        case 27: // escape
          this.hide()
          break

        default:
          this.lookup()
      }

  }

  , keypress: function (e) {
      e.stopPropagation()
      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
      }
    }

  , blur: function (e) {
      var that = this
      e.stopPropagation()
      e.preventDefault()
      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
   * =========================== */

  $.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>'
  , onselect: null
  , autoselect: true
  , autowidth: true
  , property: 'value'
  }

  $.fn.typeahead.Constructor = Typeahead


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

  $(function () {
    $('body').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 );

Inputs generally have a good amount of left and right padding and borders - I would suggest the below for a precise width.

if (that.autowidth) this.$menu.width(this.$element.outerWidth());

What say?