I have a form (2013 on premise) with a number of text fields that need to be formatted to use the thousand separator. I've got it working on the display view, however on new or edit they don't show (I'm using ##,# in the string format property field).
I'm guessing I can use the regular expression validation in the settings, but I need some help with that?
with regular expression you can only validate that the input provided meets some criteria. but regular expression will not visually format the input.
unfortunatelly as you have found format string is only applied in view mode. there is request on uservoice that asks to implement this functionality generally.