Is it possible to make HTML element attributes immutable?

If I want to make a javascript object's properties immutable, I can use Object methods such as defineProperties() , defineProperty() , and freeze() . My question is, how can I do the same with HTML element attributes?

I've already tried the aforementioned methods, and while they can be used to prevent an element's properties from being set directly (eg elem.id = 'foo'; ), as expected, the underlying attributes can still be changed via setAttribute() .

An answer of "no, it's not possible" would be acceptable, but I haven't come across any definitive statement to that effect yet.

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You could use mutation observers to restore the old attribute value.

new MutationObserver(callback)
    .observe(elem, {attributes: true, attributeOldValue: true});

function callback(mutations, observer) {
    var target = mutations[0].target;
    observer.disconnect();
    mutations.forEach(function(mutation) {
        target.setAttribute(mutation.attributeName, mutation.oldValue);
    });
    observer.observe(target, {attributes: true, attributeOldValue: true});
}

Thanks to @DoctorDestructo for the suggestions involving observer.disconnect which are necessary to avoid an infinite loop.

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