Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
Attempt to watch dom element
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>
<input id="myInput" type="checkbox"/>
<script>
if (!Object.prototype.watch) {
Object.defineProperty(Object.prototype, "watch", {
enumerable: false
, configurable: true
, writable: false
, value: function (prop, handler) {
var
oldval = this[prop]
, newval = oldval
, getter = function () {
return newval;
}
, setter = function (val) {
oldval = newval;
return newval = handler.call(this, prop, oldval, val);
}
;
if (delete this[prop]) { // can't watch constants
Object.defineProperty(this, prop, {
get: getter
, set: setter
, enumerable: true
, configurable: true
});
}
}
});
}
// object.unwatch
if (!Object.prototype.unwatch) {
Object.defineProperty(Object.prototype, "unwatch", {
enumerable: false
, configurable: true
, writable: false
, value: function (prop) {
var val = this[prop];
delete this[prop]; // remove accessors
this[prop] = val;
}
});
}
var e = document.getElementById('myInput');
e.watch('checked', function () {
console.log('changed');
});
</script>
</body>
</html>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.