selectize.js update tags and use autocomplete

Question

What I try to do:

I have recipes with related tags.

In my edit form I want to:

• Display the already associated tags with the recipe
• Add new tags. Here I want to use autocomplete by asking the database for already existing tags.

This is my script:

var $select = $('#tags').selectize({
                valueField: 'id',
                labelField: 'value',
                searchField: 'value',
                options: [
                    @foreach ($recipe->tagged as $tag)
                    {id: {{ $tag->id }}, value: '{{ $tag->tag_slug }}'},
                    @endforeach
                    ],
                create:true,
                render: {
                    option: function(item, escape) {

                        return '<div>' +
                                '<span class="name">' + escape(item.value) + '</span>' +
                                '</div>';
                    }

                },
                load: function(query, callback) {
                    if (!query.length) return callback();
                    $.ajax({
                        url: '/search/tag_autocomplete',
                        type: 'GET',
                        data: {
                            term: query
                        },
                        error: function() {
                            console.log('error');
                            callback();
                        },
                        success: function(res) {
                            //console.log(res[0].value);
                            callback(res);
                        }
                    });
                }

            });


            var selectize = $select[0].selectize;
            @foreach ($recipe->tagged as $tag)
            selectize.addItem({{ $tag->id }});
            @endforeach

By using this the autocomplete only shows the already used tags. If I use: options: [] then the autocomplete will show all tags available, but I miss the already used tags.

How can I use both:

1. Displaying the attached tags AND
2. Using autocomplete for ALL existing tags.