ko_selectize.js ; Full details and demo here - http://motorscript.com/selectize-js-binding-knockout-js/

ko_selectize.js

var inject_binding = function (allBindings, key, value) {
    //https://github.com/knockout/knockout/pull/932#issuecomment-26547528
    return {
        has: function (bindingKey) {
            return (bindingKey == key) || allBindings.has(bindingKey);
        },
        get: function (bindingKey) {
            var binding = allBindings.get(bindingKey);
            if (bindingKey == key) {
                binding = binding ? [].concat(binding, value) : value;
            }
            return binding;
        }
    };
}

ko.bindingHandlers.selectize = {
    init: function (element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
        if (!allBindingsAccessor.has('optionsText'))
            allBindingsAccessor = inject_binding(allBindingsAccessor, 'optionsText', 'name');
        if (!allBindingsAccessor.has('optionsValue'))
            allBindingsAccessor = inject_binding(allBindingsAccessor, 'optionsValue', 'id');
        if (typeof allBindingsAccessor.get('optionsCaption') == 'undefined')
            allBindingsAccessor = inject_binding(allBindingsAccessor, 'optionsCaption', 'Choose...');

        ko.bindingHandlers.options.update(element, valueAccessor, allBindingsAccessor, viewModel, bindingContext);

        var options = {
            valueField: allBindingsAccessor.get('optionsValue'),
            labelField: allBindingsAccessor.get('optionsText'),
            searchField: allBindingsAccessor.get('optionsText')
        }

        if (allBindingsAccessor.has('options')) {
            var passed_options = allBindingsAccessor.get('options')
            for (var attr_name in passed_options) {
                options[attr_name] = passed_options[attr_name];
            }
        }

        var $select = $(element).selectize(options)[0].selectize;

        if (typeof allBindingsAccessor.get('value') == 'function') {
            $select.addItem(allBindingsAccessor.get('value')());
            allBindingsAccessor.get('value').subscribe(function (new_val) {
                $select.addItem(new_val);
            })
        }

        if (typeof allBindingsAccessor.get('selectedOptions') == 'function') {
            allBindingsAccessor.get('selectedOptions').subscribe(function (new_val) {
                // Removing items which are not in new value
                var values = $select.getValue();
                var items_to_remove = [];
                for (var k in values) {
                    if (new_val.indexOf(values[k]) == -1) {
                        items_to_remove.push(values[k]);
                    }
                }

                for (var k in items_to_remove) {
                    $select.removeItem(items_to_remove[k]);
                }

                for (var k in new_val) {
                    $select.addItem(new_val[k]);
                }

            });
            var selected = allBindingsAccessor.get('selectedOptions')();
            for (var k in selected) {
                $select.addItem(selected[k]);
            }
        }


        if (typeof init_selectize == 'function') {
            init_selectize($select);
        }

        if (typeof valueAccessor().subscribe == 'function') {
            valueAccessor().subscribe(function (changes) {
                // To avoid having duplicate keys, all delete operations will go first
                var addedItems = new Array();
                changes.forEach(function (change) {
                    switch (change.status) {
                        case 'added':
                            addedItems.push(change.value);
                            break;
                        case 'deleted':
                            var itemId = change.value[options.valueField];
                            if (itemId != null) $select.removeOption(itemId);
                    }
                });
                addedItems.forEach(function (item) {
                    $select.addOption(item);
                });

            }, null, "arrayChange");
        }

    },
    update: function (element, valueAccessor, allBindingsAccessor) {

        if (allBindingsAccessor.has('object')) {
            var optionsValue = allBindingsAccessor.get('optionsValue') || 'id';
            var value_accessor = valueAccessor();
            var selected_obj = $.grep(value_accessor(), function (i) {
                if (typeof i[optionsValue] == 'function')
                    var id = i[optionsValue]
                else
                    var id = i[optionsValue]
                return id == allBindingsAccessor.get('value')();
            })[0];

            if (selected_obj) {
                allBindingsAccessor.get('object')(selected_obj);
            }
        }
    }
}

selectize_examples.html

<h3>1. Using selectize with plain select tag, with values built in view.</h3>
<select data-bind="selectize: {}">
	<option value="1">Val 1</option>
	<option value="2">Val 2</option>
</select>	

<h3>2. Using values from observable array.</h3>
<select data-bind="selectize: items, value: item_id"></select>

<h3>3. Getting selected item as an object</h3>
<select data-bind="selectize: items, value: my_item_id, object: my_item"></select>

<h3>4. Using with multiselect</h3>
<select data-bind="selectize: items, selectedOptions: selected_items" multiple></select>

<h3>5. Passing additional options</h3>
<select data-bind="selectize: items, selectedOptions: selected_items2, options: {plugins: ['remove_button']}" multiple></select>

vm.js

$(document).ready(function(){
	ko.applyBindings(new TestVM(););
});

function TestVM(){
	var self = this;

	self.items = ko.observableArray([
		{'id': 1, 'name': 'One'},
		{'id': 2, 'name': 'Two'}
		]);

	self.item_id = ko.observable();

	self.my_item_id = ko.observable();

	self.my_item = ko.observable();

	self.selected_items = ko.observableArray([1]);

	self.selected_items2 = ko.observableArray();
}

@xtranophilist What is the init_selectize variable? - it's not defined anywhere.

Would you consider putting this code into a proper project?

Hi,
When using an OptionsValue parameter the object is not set correctly.
The update needs i.id replacing with i[allBindingsAccessor().optionsValue]

or

        var optionsValue = allBindingsAccessor().optionsValue;

        var selected_obj = $.grep(value_accessor(), function (i) {
            if (typeof i[optionsValue] == 'function')
                var id = i[optionsValue]()
            else
                var id = i[optionsValue]

            return id == allBindingsAccessor.get('value')();
        })[0];

Demoed in a fiddle http://jsfiddle.net/d600burton/6j7a5/2/

Thanks for the great binding!

Thanks everybody. I've updated the binding.

@MrOpperman
This should now work with dynamically loaded data. I'd appreciate if you checked and let me know.

@MrTrick
init_selectize is a custom function where you can put your business logic that needs to be triggered when the selectize is initiated. I've used it to append 'Add New Object' at the bottom of the drop down.

@dave600b
Thank you for the fix and the love. I've incorporated it.

• X

@xtranophilist
I think line 110 was supposed to end up calling the function if it is one. Just noticed that.

I performed the change in my fork for reference.
https://gist.github.com/bmxpert1/979eb622d61341969698/revisions

Thanks for the nice binding, very helpful!

Hi, I love your binding, but I just noticed a problem I'm having with it in a specific use case. I have this code

<select data-bind="options: $root.availablePlans, optionsValue: 'title', optionsText: 'title', value: ratePlan, options: { dropdownParent: 'body', create: true, closeAfterSelect: true, createOnBlur: true }"></select>

This works great if the ratePlan observable is blank at first. As soon as I select something on the selectize input the model is updated. But if ratePlan was set in the beginning, I see the proper option selected in the input, but the KO model observable is updated with "undefined". So when I submit the form I lose the information. I looked at the source and could not find a reason for this. If I remove the value binding on the component then it stays with the value it had (it is not overwritten to undefined). If I replace the selectize binding with a normal options binding, it works well.

Anyone else run into this?

@stechnique
You are using options binding and not selectize binding?

@xtranophilist

<select data-bind="selectize: $root.Exercises, value: ExerciseID, optionsValue: function(item){return item.ExerciseID()}, optionsText: function(item){return item.ExerciseName();},  opt: {create: $root.CreateExercise}"></select>

The list does not seem to be updated when the associated observable array has items added. However, if I create a new instance of this same binding it has the updated items. I presume it's a problem with the update function, but I'm not exactly sure what needs to happen to get it working properly.

EDIT: I should note that I am simply pushing items into the observable array.

The destroy method does not revert the item properly. For example tabIndex is left at -1. See destroy method here for missing parameters:
https://github.com/brianreavis/selectize.js/blob/master/src/selectize.js

Does tagging work with this script? The first two examples here: http://brianreavis.github.io/selectize.js/

Addresses https://gist.github.com/xtranophilist/8001624#gistcomment-1553750
https://gist.github.com/tejovanthn/a0671955605251fb610c

Is this binding only working in Knockout 3.0+? I'm working on an old knockout app that's stuck on 2.2.1 and this is the best option to use, but if I have to update Knockout to 3+ it may not be worth it.

I am having an issue when using webpack 3.10.0 where ko.subscribe is no longer triggered in this binding... any ideas why?

How would this work with option groups?