textinputform.dart

  Widget build(BuildContext context) {
    return TextFormField(
      controller: widget.controller,
      keyboardType: keyBoardType(widget.type),
      validator: (str)=>validator(str), ///this is a function which returns the error message we defined using the validator object
      decoration: InputDecoration(
        hintText: widget.hint,
        labelText: widget.label,
        helperText: widget.hint,
      ),
    );
  }