custom-event-polyfill.js

// Polyfill for creating CustomEvents on IE9/10/11

// code pulled from:
// https://github.com/d4tocchini/customevent-polyfill
// https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent#Polyfill

(function () {
    if (typeof window === 'undefined') {
        return;
    }

    try {
        var ce = new window.CustomEvent('test', {cancelable: true});
        ce.preventDefault();
        if (ce.defaultPrevented !== true) {
            // IE has problems with .preventDefault() on custom events
            // http://stackoverflow.com/questions/23349191
            throw new Error('Could not prevent default');
        }
    } catch(e) {
        var CustomEvent = function(event, params) {
            var evt, origPrevent;
            params = params || {
                bubbles: false,
                cancelable: false,
                detail: undefined
            };

            evt = document.createEvent("CustomEvent");
            evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail);
            origPrevent = evt.preventDefault;
            evt.preventDefault = function () {
                origPrevent.call(this);
                try {
                    Object.defineProperty(this, 'defaultPrevented', {
                        get: function () {
                            return true;
                        }
                    });
                } catch(e) {
                    this.defaultPrevented = true;
                }
            };
            return evt;
        };

        CustomEvent.prototype = window.Event.prototype;
        window.CustomEvent = CustomEvent; // expose definition to window
    }
})();