Autocomplete tags with forcing and free text

Question

I need to have a multiline textbox with a free text allowed, but If I start type-in characters: "@@"
the autocomplete box with available tags should show up and allow me to select tags from existing, and "@@" characters should not be present in the tag name.

Currently I'm playing with tag-it plugin for jquery UI but cannot figure out how to allow free text and only shw autocomplete box on "@@" enter. and how to user textarea instead of regular input.

Also, I'd like to force them to select from the list if they enter @@ and do not allow to type free text (first available selection would be good)
Javascript:

$(document).ready(function() {

  //The demo tag array
  var availableTags = [
    {value: 1, label: 'tag1'},
    {value: 2, label: 'tag2'},
    {value: 3, label: 'tag3'}];

  //The text input
  var input = $("input#text");

  //The tagit list
  var instance = $("<ul class=\"tags\"></ul>");

  //Store the current tags
  //Note: the tags here can be split by any of the trigger keys
  //      as tagit will split on the trigger keys anything passed  
  var currentTags = input.val();

  //Hide the input and append tagit to the dom
  input.hide().after(instance);

  //Initialize tagit
  instance.tagit({
    tagSource:availableTags,
    tagsChanged:function () {

      //Get the tags            
      var tags = instance.tagit('tags');
      var tagString = [];

      //Pull out only value
      for (var i in tags){
        tagString.push(tags[i].value);
      }

      //Put the tags into the input, joint by a ','
      input.val(tagString.join(','));
    }
  });

  //Add pre-loaded tags to tagit
  instance.tagit('add', currentTags);
});

html:

<p>This example shows how to use Tagit on an input!</p>
<input type="text" id="text" name="tags" value="one,two,three"/>
​

testing here: http://jsfiddle.net/hailwood/u8zj5/

Answer 1

Since you had used tag-it plugin.. I have added some handler to the input to handle

1. @@ to show auto complete as you type
2. Free text if typed without @@

I still need time to look into the Do not allow free text if @@ is typed

DEMO: http://jsfiddle.net/xBgfJ/2/ and below is the full code,

Note: Below code is tweak to the existing plugin code.

$(document).ready(function() {

    //The demo tag array
    var availableTags = [{value: 1, label: 'tag1'},{ value: 2,label: 'tag2'}, { value: 3, label: 'tag3'}];

    //The text input
    var input = $("input#text");

    //The tagit list
    var instance = $("<ul class=\"tags\"></ul>");

    //Store the current tags
    //Note: the tags here can be split by any of the trigger keys
    //      as tagit will split on the trigger keys anything passed  
    var currentTags = input.val();

    //Hide the input and append tagit to the dom
    input.hide().after(instance);

    //Initialize tagit
    instance.tagit({
        tagSource: availableTags,
        tagsChanged: function() {

            //Get the tags            
            var tags = instance.tagit('tags');
            var tagString = [];

            //Pull out only value
            for (var i in tags) {
                tagString.push(tags[i].value);
            }

            //Put the tags into the input, joint by a ','
            input.val(tagString.join(','));
        },
        onTagAdded: function() {
            inpNext.parent().find('.pre-filter').remove();
        }
    });

    //Add pre-loaded tags to tagit
    instance.tagit('add', currentTags);

    var inpNext = input.next();
    var autoCompelteMenu = $('.ui-autocomplete', inpNext);

    inpNext.on('keydown', '.tagit-input', function(e) {
        var $parent = $(this).parent();
        var $preFilter = $parent.find('.pre-filter');
        if (e.which == 8 && this.value == '') { //backspace           
            $preFilter.remove();
        } else if (e.which == 9 || e.which == 32
                  || e.which == 188 || e.which ==  44 ||
                  e.which == 13 ) { //tab or space, comma and enter
            $preFilter.remove();
            autoCompelteMenu.css('opacity', 0);
        }

    }).on('keypress', '.tagit-input', function(e) {

        var $parent = $(this).parent();
        var $preFilter = $parent.find('.pre-filter');

        if (e.which == 64 && !$preFilter.length) {
            $parent.prepend('<span class="pre-filter hidden">@</span>');
            autoCompelteMenu.css('opacity', 0);
        } else if ( e.which == 64 && $preFilter.length) {
            e.preventDefault();
            this.value = '';
            $preFilter.append('@').removeClass('hidden');
            autoCompelteMenu.css('opacity', 1);
        }

        return;

    }).on('blur', '.tagit-input', function() {
        $(this).parent().find('span').remove();
        autoCompelteMenu.css('opacity', 0);
    });
});