svoid mapMethodLike dm_fileFieldDialog(fS field, fO... _) {
  DynModule m = dm_current_mandatory();
  S humanized = humanizeFormLabel(field);
  JTextField tf = jtextfield(strOrNull(get(m, field)));
  showFormTitled(or2(stringOptPar(_, 'formTitle), "Set " + humanized),
    humanized + ":", tf, r {
      m.setField(field, toFile_nullOnEmpty(gtt(tf)));
      callF(optPar(_, 'onSet));
    });
}

Began life as a copy of #1022768