import { ValidationError, ValidatorFunction } from '../models';
export declare class Validators {
    /**
     * Requires the control's value to be non-empty
     * @returns null if control's value meets the
     * requirements, if not returns an error object with
     * required property as true
     */
    static required: (value: any) => ValidationError | null;
    /**
     * Requires the control's value to be true
     * @returns null if control's value meets the
     * requirements, if not returns an error object with
     * required property as true
     */
    static requiredTrue: (value: any) => ValidationError | null;
    /**
     * Requires the control's value to match a regex pattern
     * @param pattern - provided regex pattern
     * @returns null if control's value meets the
     * requirements, if not returns an error object with
     * pattern property as true
     */
    static pattern: (regex: RegExp) => ValidatorFunction;
    /**
     * Requires the control's value to be greater than or equal to the provided number.
     * @param min - provided min number
     * @returns null if control's value meets the
     * requirements, if not returns an error object with min
     * property as true
     */
    static min: (minValue: number) => ValidatorFunction;
    /**
     * Requires the control's value to be less than or equal to the provided number.
     * @param max - provided max number
     * @returns null if control's value meets the
     * requirements, if not returns an error object with max
     * property as true
     */
    static max: (maxValue: number) => ValidatorFunction;
    /**
     * Requires the length of the control's value to be
     * greater than or equal to the provided minimum length
     * @param minLength - provided minimum length
     * @returns null if control's value meets the
     * requirements, if not returns an error object with
     * minLength property as true
     */
    static minLength: (minLengthValue: number) => ValidatorFunction;
    /**
     * Requires the length of the control's value to be
     * less than or equal to the provided maximum length
     * @param maxLength - provided maximum length
     * @returns null if control's value meets the
     * requirements, if not returns an error object with
     * maxLength property as true
     */
    static maxLength: (maxLengthValue: number) => ValidatorFunction;
    /**
     * Checks if value is empty
     * @param value - value to check
     * @returns if is empty returns true, if not returns false
     */
    private static _isEmpty;
}