Knockout binding for bootstrap-slider. Fixes case when jQuery UI is already bound to $(element).slider().

bootstrap-slider-knockout-bindings.js

// Slider: https://github.com/seiyria/bootstrap-slider

// When $(element).slider() is already defined by jQuery UI 
// we use the alternative binding $(element).bootstrapSlider()

ko.bindingHandlers.sliderValue = {
    init: function (element, valueAccessor, allBindings, viewModel, bindingContext) {
        var params = valueAccessor();

        var slider = $.fn.slider ? 'bootstrapSlider' : 'slider';

        // Check whether the value observable is either placed directly or in the paramaters object.
        if (!(ko.isObservable(params) || params['value']))
            throw "You need to define an observable value for the sliderValue. Either pass the observable directly or as the 'value' field in the parameters.";

        // Identify the value and initialize the slider
        var valueObservable;
        if (ko.isObservable(params)) {
            valueObservable = params;
            $(element)[slider]({ value: ko.unwrap(params) });
        }
        else {
            valueObservable = params['value'];
            // Replace the 'value' field in the options object with the actual value
            params['value'] = ko.unwrap(valueObservable);
            $(element)[slider](params);
        }

        // Make sure we update the observable when changing the slider value
        $(element).on('slide', function (ev) {
            valueObservable(ev.value);
        });

    },

    update: function (element, valueAccessor, allBindings, viewModel, bindingContext) {
        var slider = $.fn.slider ? 'bootstrapSlider' : 'slider';
        var modelValue = valueAccessor();
        var valueObservable;
        if (ko.isObservable(modelValue))
            valueObservable = modelValue;
        else
            valueObservable = modelValue['value'];

        $(element)[slider]('setValue', valueObservable());
    }
};