I am relatively new to the SmartThings environment. I have a general understanding that a Device communicates with the SmartThings cloud (and SmartThings Hub) by virtue of its Device Handler. I have also noticed that the IDE can be employed to change Device Handlers (eg, to use a custom device handler so something like the ZWaveTweaker device handler).
I noticed that changing the Device Handler for a particular device not only changes the functionality (to some limited extent), but also the user interface (eg, the screen that appears in the Classic App when you select the particular device associated with that device handler). The simplest example is ZWaveTweaker, which provides a “custom” interface for changing a device’s parameters.
I am wondering how (and the extent to which) the device handler can control the user interface that shows up in the Classic App. Can someone point me to the place in the Smartthings documentation that explains the APIs or other mechanisms for controlling not only device functionality/communication, but also the UI in the classic app?