ShareJS attachSelect

attachSelect.js

// code that allows attaching ShareJS to HTML <select> fields

sharejs.Doc.prototype.attachSelect = function (innerElem, ctx) {
    var i;
    var rawValue = innerElem.value;

    var elem = {
        get value () {
            return rawValue;
        },
        set value (v) {
            rawValue = v;
            innerElem.value = v;
        }
    };

    var eventFuncs = ['addEventListener', 'attachEvent', 'removeEventListener', 'detachEvent'];
    for (i = 0; i < eventFuncs.length; ++i) {
        if (innerElem[eventFuncs[i]]) {
            elem[eventFuncs[i]] = innerElem[eventFuncs[i]].bind(innerElem);
        }
    }

    var changeHandler = function () {
        rawValue = innerElem.value;
        innerElem.dispatchEvent(new Event('textInput'));
    };

    var delayedChangeHandler = function () {
        setTimeout(changeHandler, 0);
    };

    var addEvent = function (event, handler) {
        if (innerElem.addEventListener) {
            innerElem.addEventListener(event, handler, false);
        } else {
            innerElem.attachEvent('on' + event, handler);
        }
    };

    var removeEvent = function (event, handler) {
        if (innerElem.removeEventListener) {
            innerElem.removeEventListener(event, handler, false);
        } else {
            innerElem.detachEvent('on' + event, handler);
        }
    };

    addEvent('change', changeHandler);
    addEvent('keyup', changeHandler);
    addEvent('keydown', delayedChangeHandler);

    if (!ctx) {
        ctx = this.createContext();
    }

    ctx.detach = function () {
        removeEvent('change', changeHandler);
        removeEvent('keyup', changeHandler);
        removeEvent('keydown', delayedChangeHandler);
    };

    return this.attachTextarea(elem, ctx);
};