missing default_value_for parameter flutter

Question

I m creating a reusable widget TextFormField.

Error:

Code:

import 'package:flutter/material.dart';

class TextFormFieldWidget extends StatelessWidget {
  final TextInputType textInputType;
  final String hintText;
  final Widget prefixIcon;
  final String defaultText;
  final FocusNode focusNode;
  final bool obscureText;
  final TextEditingController controller;
  final Function functionValidate;
  final String parametersValidate;
  final TextInputAction actionKeyboard;
  final Function onSubmitField;
  final Function onFieldTap;

  const TextFormFieldWidget(
      {Key? key,
      this.hintText,
      this.focusNode,
      this.textInputType,
      this.defaultText,
      this.obscureText = false,
      this.controller,
      this.functionValidate,
      this.parametersValidate,
      this.actionKeyboard = TextInputAction.next,
      this.onSubmitField,
      this.onFieldTap,
      this.prefixIcon})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

score 0 · Answer 1 · answered Oct 10 '21 at 07:33

If all fields should be passed to the constructor, you can use required keyword in the constructor, but if some fields are optional you can use ? to tell the dart that it's ok I know some values may be null:

import 'package:flutter/material.dart';

class TextFormFieldWidget extends StatelessWidget {
  final TextInputType? textInputType;
  final String? hintText;
  final Widget? prefixIcon;
  final String? defaultText;
  final FocusNode? focusNode;
  final bool? obscureText;
  final TextEditingController? controller;
  final Function? functionValidate;
  final String? parametersValidate;
  final TextInputAction? actionKeyboard;
  final Function? onSubmitField;
  final Function? onFieldTap;

  const TextFormFieldWidget(
      {Key? key,
      this.hintText,
      this.focusNode,
      this.textInputType,
      this.defaultText,
      this.obscureText = false,
      this.controller,
      this.functionValidate,
      this.parametersValidate,
      this.actionKeyboard = TextInputAction.next,
      this.onSubmitField,
      this.onFieldTap,
      this.prefixIcon})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

but the better way is to provide default value for your fields like this.actionKeyboard = TextInputAction.next

missing default_value_for parameter flutter

1 Answers1