import { FormFieldStatusMeta, FormFieldValueType } from './form-field-validation-rule';
import { EvaluateResult } from './validation-rule';
import { InternalFormFieldValidationRule } from './internal-form-field-validation-rule.abstract';
/**
 * A rule that checks if a string is empty or not
 *
 * @augments {InternalFormFieldValidationRule<string>}
 */
export declare class RequiredFieldRule extends InternalFormFieldValidationRule<FormFieldValueType | Array<FormFieldValueType>> {
  /**
   * If the input is a number or a boolean, return true. If the input is a string, return true if the string is not empty
   *
   * @param {FormFieldValueType | Array<FormFieldValueType>} input - The input to be evaluated.
   * @returns {EvaluateResult} An object with two properties: isValid and message.
   */
  evaluate(input: FormFieldValueType | Array<FormFieldValueType>): EvaluateResult;
  /**
   * If the input is accepted and the status is not disabled and visible, then return true
   *
   * @param {unknown} input - The input to be evaluated.
   * @param {FormFieldStatusMeta} [status] - FormFieldStatusMeta
   * @returns {boolean} The return value is a boolean that indicates whether the input can be evaluated.
   */
  canEvaluate(input: unknown, status?: FormFieldStatusMeta): boolean;
  /**
   * If the field is not disabled, visible, and has been touched or modified, then show the error
   *
   * @param {FormFieldStatusMeta} status - FormFieldStatusMeta
   * @returns {boolean} A boolean value.
   */
  shouldShowError(status: FormFieldStatusMeta): boolean;
  /**
   * A function that checks if the item is a string, number, or boolean.
   *
   * @param {unknown} item - The item to be checked.
   * @returns {boolean} The return value is a boolean that indicates whether the item is string, number or boolean.
   */
  checkArrayItemType: (item: unknown) => boolean;
  /**
   * If the input is a string, number, boolean, or null, return true, otherwise return false.
   *
   * @param {unknown} input - The input value to be validated.
   * @returns {boolean} a boolean value.
   */
  private isAcceptedInputType;
}
