How to add a timestamp for when the Firebase object/node+subtree was modified?
<p>I'm looking to create a field for storing the timestamp of when the object was last changed. So if any of the object's properties (aka subtree) is modified, be able to set a timestamp field to the current time.</p>

<p>Firebase doesn't seem to have a way to keep track of when an object was last updated. Has anyone actually implemented a way to do this in an elegant fashion?</p>