twoway binding for innerText (textContent in firefox) property on DOM element

ko-innertext-binding.js

/*
 *
 * innertext binding - twoway binding between dom and knockout observable
 *
 */

// Helper class
var KOInnerTextHelper = (typeof KOInnerTextHelper !== 'undefined') ? 
    KOInnerTextHelper : 
    function () {
        this.getInnerText = function (element) {
            // Not all browsers support innterText...
            if (element.innerText) {
                return element.innerText;
            }

            // Firefox uses textContent
            return element.textContent;
        };        

        this.setInnerText = function (element, text) {
            // Not all browsers support innterText...
            if (element.innerText) {
                element.innerText = text;
            }

            // Firefox uses textContent
            element.textContent = text;
        }
    };

// Binding methods
var KOInnerTextBindingInit = (typeof KOInnerTextBindingInit !== "undefined") ?
    KOInnerTextBindingInit :
    function (element, valueAccessor) {
        var observable = valueAccessor();
        var helper = new KOInnerTextHelper();
        
        element.addEventListener("DOMSubtreeModified", function () {
        observable(helper.getInnerText(element));
    });
};

var KOInnerTextBindingUpdate = (typeof KOInnerTextBindingUpdate !== "undefined") ?
    KOInnerTextBindingUpdate :
    function (element, valueAccessor) {
        // Might not be observable, safer to call ko.unwrap(...) to get actual value
        var value = ko.unwrap(valueAccessor());
        var helper = new EasyInnerTextHelper();
        helper.setInnerText(element, value);
    }

// Create binding
ko.bindingHandlers.innerText = {
    init: KOInnerTextBindingInit,
    update: KOInnerTextBindingUpdate
};