Pdftk form filling font resize

Question

I\'m using pdftk to fill inputs in a pdf form. I have no problem to generate a XFDF file and merge data & template, but sometimes the value is longer than the field, and

Answer 1

It's not cut, it's just not shown. Text field can be scrollable. Then, if text doesn't fit, there's visual indicator in field's corner, in e.g. Reader, but that's probably not what you want.

Text field can have automatic font size, and then best practice, I think, would be to set field height so that it limits text font size for short strings (even for single character), and font size only starts changing (diminishing) when string length exceeds field size.

Automatic text size is set by zero font size in default appearance /DA entry of field dictionary (or its parent, because this property is inheritable), like this: /Helv 0 Tf 0 g

But, of course you can post-process merged PDF: calculate string length and adjust font size of offending fields.