Addeventlistener('keydown',handlekeydown,false) Vs. .onkeydown Working Differently For Replacing Typed Keystroke

I am using a 'keydown' event to replace specific characters typed in an input textbox. When I use: document.getElementById('inputText').onkeydown = handleInputTextKeydown; or the

Solution 1:

Because you have to prevent the default behavior with the .addEventListener() version.

Returning false at the end of the handler to prevent the default behavior is a jQuery-specific feature and a feature of the .onkeydown property, but not something that works with .addEventListener('keydown').

You will need to call e.preventDefault() (for modern browsers) or set e.returnValue = false (for non-standard browsers).

---

This is more than you need to solve your problem, but when working in plain javascript, I use a cross browser event handling stub that allows me to return false like this:

// refined add event cross browserfunctionaddEvent(elem, event, fn) {
    // allow the passing of an element id string instead of the DOM elemif (typeof elem === "string") {
        elem = document.getElementById(elem);
    }

    functionlistenHandler(e) {
        var ret = fn.apply(this, arguments);
        if (ret === false) {
            e.stopPropagation();
            e.preventDefault();
        }
        return(ret);
    }

    functionattachHandler() {
        // normalize the target of the eventwindow.event.target = window.event.srcElement;
        // make sure the event is passed to the fn also so that works the same too// set the this pointer same as addEventListener when fn is calledvar ret = fn.call(elem, window.event);   
        // support an optional return false to be cancel propagation and prevent default handling// like jQuery doesif (ret === false) {
            window.event.returnValue = false;
            window.event.cancelBubble = true;
        }
        return(ret);
    }

    if (elem.addEventListener) {
        elem.addEventListener(event, listenHandler, false);
    } else {
        elem.attachEvent("on" + event, attachHandler);
    }
}