Filling and monitoring text field changes

I have a form which I track to see if is dirty (a value has changed) and enable a "Save" button if it is. Take a look here

You only have one field, so you could use a simplified version of that pattern. Save the value or textInput1.value to state1 on data refresh, then simply check state1.value === textInput1.value wherever you need to see if it's changed.