There is still a watch() mechanism that from a consumers point of view hide the originating event of an update. Otherwise if all you wanted was functions, just

There is still a watch() mechanism that from a consumers point of view hide the originating event of an update. Otherwise if all you wanted was functions, just use functions. When watch fires out of control, you need debugging tools to understand why your render() function is being invoked more often than it should. This type of problem happens all the time in react and you need to trace upwards to find that 7 components up the chain someone accidentally included new Date() in the state that propagates down through props and re-renders everything.