Class FieldArrayInner

packages/formik/src/FieldArray.tsx:140–390

};

class FieldArrayInner<Values = {}> extends React.Component<
  FieldArrayConfig & { formik: FormikContextType<Values> },
  {}
> {
  static defaultProps = {
    validateOnChange: true,
  };

  constructor(props: FieldArrayConfig & { formik: FormikContextType<Values> }) {
    super(props);
    // We need TypeScript generics on these, so we'll bind them in the constructor
    // @todo Fix TS 3.2.1
    this.remove = this.remove.bind(this) as any;
    this.pop = this.pop.bind(this) as any;
  }

  componentDidUpdate(
    prevProps: FieldArrayConfig & { formik: FormikContextType<Values> }
  ) {
    if (
      this.props.validateOnChange &&
      this.props.formik.validateOnChange &&
      !isEqual(
        getIn(prevProps.formik.values, prevProps.name),
        getIn(this.props.formik.values, this.props.name)
      )
    ) {
      this.props.formik.validateForm(this.props.formik.values);
    }
  }

  updateArrayField = (
    fn: Function,
    alterTouched: boolean | Function,
    alterErrors: boolean | Function
  ) => {
    const {
      name,

      formik: { setFormikState },
    } = this.props;

    setFormikState((prevState: FormikState<any>) => {
      let updateErrors = createAlterationHandler(alterErrors, fn);
      let updateTouched = createAlterationHandler(alterTouched, fn);

      // values fn should be executed before updateErrors and updateTouched,
      // otherwise it causes an error with unshift.
      let values = setIn(
        prevState.values,
        name,
        fn(getIn(prevState.values, name))
      );

      let fieldError = alterErrors
        ? updateErrors(getIn(prevState.errors, name))
        : undefined;
      let fieldTouched = alterTouched