import { ValidatorFn } from '@angular/forms';
import * as i0 from "@angular/core";
export declare class FormValidation {
    static notAllowedString(str: string): ValidatorFn;
    static notAllowedNumber(num: number): ValidatorFn;
    static invalidNumber(): ValidatorFn;
    static minimumNumber(min: number): ValidatorFn;
    static maximumNumber(max: number): ValidatorFn;
    static minimumStringLength(minLength: number): ValidatorFn;
    static maximumStringLength(maxLength: number): ValidatorFn;
    static minimumDate(minDate: Date): ValidatorFn;
    static maximumDate(maxDate: Date): ValidatorFn;
    static relativeMinimumDate(field: string): ValidatorFn;
    static relativeMaximumDate(field: string): ValidatorFn;
    /**
     * Helper method for validatorFn's checking a date range.
     * @param startDate Start of range string date
     * @param endDate End of range string date
     * @param maxMonths Maximum allowed months (exclusive)
     */
    static checkRangeValid(startDate: Date | string, endDate: Date | string, maxMonths: number): boolean;
    /**
     * Validates that two dates are at most a certain time length apart in months.
     * @param startDateControlName
     * @param endDateControlName
     * @param maxMonths Number representing how far apart two dates can be.
     */
    static maxRange(startDateControlName: string, endDateControlName: string, maxMonths: number): ValidatorFn;
    static validateIfChanged(validatorFn: ValidatorFn, originalValue: any): ValidatorFn;
    static ɵfac: i0.ɵɵFactoryDeclaration<FormValidation, never>;
    static ɵprov: i0.ɵɵInjectableDeclaration<FormValidation>;
}