/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
import { InjectionToken } from '@angular/core';
import { Observable } from 'rxjs';
import { AsyncValidator, AsyncValidatorFn, ValidationErrors, Validator, ValidatorFn } from './directives/validators';
import { AbstractControl } from './model/abstract_model';
/**
 * @description
 * An `InjectionToken` for registering additional synchronous validators used with
 * `AbstractControl`s.
 *
 * @see {@link NG_ASYNC_VALIDATORS}
 *
 * @usageNotes
 *
 * ### Providing a custom validator
 *
 * The following example registers a custom validator directive. Adding the validator to the
 * existing collection of validators requires the `multi: true` option.
 *
 * ```typescript
 * @Directive({
 *   selector: '[customValidator]',
 *   providers: [{provide: NG_VALIDATORS, useExisting: CustomValidatorDirective, multi: true}]
 * })
 * class CustomValidatorDirective implements Validator {
 *   validate(control: AbstractControl): ValidationErrors | null {
 *     return { 'custom': true };
 *   }
 * }
 * ```
 *
 * @publicApi
 */
export declare const NG_VALIDATORS: InjectionToken<readonly (Function | Validator)[]>;
/**
 * @description
 * An `InjectionToken` for registering additional asynchronous validators used with
 * `AbstractControl`s.
 *
 * @see {@link NG_VALIDATORS}
 *
 * @usageNotes
 *
 * ### Provide a custom async validator directive
 *
 * The following example implements the `AsyncValidator` interface to create an
 * async validator directive with a custom error key.
 *
 * ```typescript
 * @Directive({
 *   selector: '[customAsyncValidator]',
 *   providers: [{provide: NG_ASYNC_VALIDATORS, useExisting: CustomAsyncValidatorDirective, multi:
 * true}]
 * })
 * class CustomAsyncValidatorDirective implements AsyncValidator {
 *   validate(control: AbstractControl): Promise<ValidationErrors|null> {
 *     return Promise.resolve({'custom': true});
 *   }
 * }
 * ```
 *
 * @publicApi
 */
export declare const NG_ASYNC_VALIDATORS: InjectionToken<readonly (Function | Validator)[]>;
/**
 * @description
 * Provides a set of built-in validators that can be used by form controls.
 *
 * A validator is a function that processes a `FormControl` or collection of
 * controls and returns an error map or null. A null map means that validation has passed.
 *
 * @see [Form Validation](/guide/form-validation)
 *
 * @publicApi
 */
export declare class Validators {
    /**
     * @description
     * Validator that requires the control's value to be greater than or equal to the provided number.
     *
     * @usageNotes
     *
     * ### Validate against a minimum of 3
     *
     * ```typescript
     * const control = new FormControl(2, Validators.min(3));
     *
     * console.log(control.errors); // {min: {min: 3, actual: 2}}
     * ```
     *
     * @returns A validator function that returns an error map with the
     * `min` property if the validation check fails, otherwise `null`.
     *
     * @see {@link updateValueAndValidity()}
     *
     */
    static min(min: number): ValidatorFn;
    /**
     * @description
     * Validator that requires the control's value to be less than or equal to the provided number.
     *
     * @usageNotes
     *
     * ### Validate against a maximum of 15
     *
     * ```typescript
     * const control = new FormControl(16, Validators.max(15));
     *
     * console.log(control.errors); // {max: {max: 15, actual: 16}}
     * ```
     *
     * @returns A validator function that returns an error map with the
     * `max` property if the validation check fails, otherwise `null`.
     *
     * @see {@link updateValueAndValidity()}
     *
     */
    static max(max: number): ValidatorFn;
    /**
     * @description
     * Validator that requires the control have a non-empty value.
     *
     * @usageNotes
     *
     * ### Validate that the field is non-empty
     *
     * ```typescript
     * const control = new FormControl('', Validators.required);
     *
     * console.log(control.errors); // {required: true}
     * ```
     *
     * @returns An error map with the `required` property
     * if the validation check fails, otherwise `null`.
     *
     * @see {@link updateValueAndValidity()}
     *
     */
    static required(control: AbstractControl): ValidationErrors | null;
    /**
     * @description
     * Validator that requires the control's value be true. This validator is commonly
     * used for required checkboxes.
     *
     * @usageNotes
     *
     * ### Validate that the field value is true
     *
     * ```typescript
     * const control = new FormControl('some value', Validators.requiredTrue);
     *
     * console.log(control.errors); // {required: true}
     * ```
     *
     * @returns An error map that contains the `required` property
     * set to `true` if the validation check fails, otherwise `null`.
     *
     * @see {@link updateValueAndValidity()}
     *
     */
    static requiredTrue(control: AbstractControl): ValidationErrors | null;
    /**
     * @description
     * Validator that requires the control's value pass an email validation test.
     *
     * Tests the value using a [regular
     * expression](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions)
     * pattern suitable for common use cases. The pattern is based on the definition of a valid email
     * address in the [WHATWG HTML
     * specification](https://html.spec.whatwg.org/multipage/input.html#valid-e-mail-address) with
     * some enhancements to incorporate more RFC rules (such as rules related to domain names and the
     * lengths of different parts of the address).
     *
     * The differences from the WHATWG version include:
     * - Disallow `local-part` (the part before the `@` symbol) to begin or end with a period (`.`).
     * - Disallow `local-part` to be longer than 64 characters.
     * - Disallow the whole address to be longer than 254 characters.
     *
     * If this pattern does not satisfy your business needs, you can use `Validators.pattern()` to
     * validate the value against a different pattern.
     *
     * @usageNotes
     *
     * ### Validate that the field matches a valid email pattern
     *
     * ```typescript
     * const control = new FormControl('bad@', Validators.email);
     *
     * console.log(control.errors); // {email: true}
     * ```
     *
     * @returns An error map with the `email` property
     * if the validation check fails, otherwise `null`.
     *
     * @see {@link updateValueAndValidity()}
     *
     */
    static email(control: AbstractControl): ValidationErrors | null;
    /**
     * @description
     * Validator that requires the length of the control's value to be greater than or equal
     * to the provided minimum length. This validator is also provided by default if you use the
     * the HTML5 `minlength` attribute. Note that the `minLength` validator is intended to be used
     * only for types that have a numeric `length` property, such as strings or arrays. The
     * `minLength` validator logic is also not invoked for values when their `length` property is 0
     * (for example in case of an empty string or an empty array), to support optional controls. You
     * can use the standard `required` validator if empty values should not be considered valid.
     *
     * @usageNotes
     *
     * ### Validate that the field has a minimum of 3 characters
     *
     * ```typescript
     * const control = new FormControl('ng', Validators.minLength(3));
     *
     * console.log(control.errors); // {minlength: {requiredLength: 3, actualLength: 2}}
     * ```
     *
     * ```html
     * <input minlength="5">
     * ```
     *
     * @returns A validator function that returns an error map with the
     * `minlength` property if the validation check fails, otherwise `null`.
     *
     * @see {@link updateValueAndValidity()}
     *
     */
    static minLength(minLength: number): ValidatorFn;
    /**
     * @description
     * Validator that requires the length of the control's value to be less than or equal
     * to the provided maximum length. This validator is also provided by default if you use the
     * the HTML5 `maxlength` attribute. Note that the `maxLength` validator is intended to be used
     * only for types that have a numeric `length` property, such as strings or arrays.
     *
     * @usageNotes
     *
     * ### Validate that the field has maximum of 5 characters
     *
     * ```typescript
     * const control = new FormControl('Angular', Validators.maxLength(5));
     *
     * console.log(control.errors); // {maxlength: {requiredLength: 5, actualLength: 7}}
     * ```
     *
     * ```html
     * <input maxlength="5">
     * ```
     *
     * @returns A validator function that returns an error map with the
     * `maxlength` property if the validation check fails, otherwise `null`.
     *
     * @see {@link updateValueAndValidity()}
     *
     */
    static maxLength(maxLength: number): ValidatorFn;
    /**
     * @description
     * Validator that requires the control's value to match a regex pattern. This validator is also
     * provided by default if you use the HTML5 `pattern` attribute.
     *
     * @usageNotes
     *
     * ### Validate that the field only contains letters or spaces
     *
     * ```typescript
     * const control = new FormControl('1', Validators.pattern('[a-zA-Z ]*'));
     *
     * console.log(control.errors); // {pattern: {requiredPattern: '^[a-zA-Z ]*$', actualValue: '1'}}
     * ```
     *
     * ```html
     * <input pattern="[a-zA-Z ]*">
     * ```
     *
     * ### Pattern matching with the global or sticky flag
     *
     * `RegExp` objects created with the `g` or `y` flags that are passed into `Validators.pattern`
     * can produce different results on the same input when validations are run consecutively. This is
     * due to how the behavior of `RegExp.prototype.test` is
     * specified in [ECMA-262](https://tc39.es/ecma262/#sec-regexpbuiltinexec)
     * (`RegExp` preserves the index of the last match when the global or sticky flag is used).
     * Due to this behavior, it is recommended that when using
     * `Validators.pattern` you **do not** pass in a `RegExp` object with either the global or sticky
     * flag enabled.
     *
     * ```typescript
     * // Not recommended (since the `g` flag is used)
     * const controlOne = new FormControl('1', Validators.pattern(/foo/g));
     *
     * // Good
     * const controlTwo = new FormControl('1', Validators.pattern(/foo/));
     * ```
     *
     * @param pattern A regular expression to be used as is to test the values, or a string.
     * If a string is passed, the `^` character is prepended and the `$` character is
     * appended to the provided string (if not already present), and the resulting regular
     * expression is used to test the values.
     *
     * @returns A validator function that returns an error map with the
     * `pattern` property if the validation check fails, otherwise `null`.
     *
     * @see {@link updateValueAndValidity()}
     *
     */
    static pattern(pattern: string | RegExp): ValidatorFn;
    /**
     * @description
     * Validator that performs no operation.
     *
     * @see {@link updateValueAndValidity()}
     *
     */
    static nullValidator(control: AbstractControl): ValidationErrors | null;
    /**
     * @description
     * Compose multiple validators into a single function that returns the union
     * of the individual error maps for the provided control.
     *
     * @returns A validator function that returns an error map with the
     * merged error maps of the validators if the validation check fails, otherwise `null`.
     *
     * @see {@link updateValueAndValidity()}
     *
     */
    static compose(validators: null): null;
    static compose(validators: (ValidatorFn | null | undefined)[]): ValidatorFn | null;
    /**
     * @description
     * Compose multiple async validators into a single function that returns the union
     * of the individual error objects for the provided control.
     *
     * @returns A validator function that returns an error map with the
     * merged error objects of the async validators if the validation check fails, otherwise `null`.
     *
     * @see {@link updateValueAndValidity()}
     *
     */
    static composeAsync(validators: (AsyncValidatorFn | null)[]): AsyncValidatorFn | null;
}
/**
 * Validator that requires the control's value to be greater than or equal to the provided number.
 * See `Validators.min` for additional information.
 */
export declare function minValidator(min: number): ValidatorFn;
/**
 * Validator that requires the control's value to be less than or equal to the provided number.
 * See `Validators.max` for additional information.
 */
export declare function maxValidator(max: number): ValidatorFn;
/**
 * Validator that requires the control have a non-empty value.
 * See `Validators.required` for additional information.
 */
export declare function requiredValidator(control: AbstractControl): ValidationErrors | null;
/**
 * Validator that requires the control's value be true. This validator is commonly
 * used for required checkboxes.
 * See `Validators.requiredTrue` for additional information.
 */
export declare function requiredTrueValidator(control: AbstractControl): ValidationErrors | null;
/**
 * Validator that requires the control's value pass an email validation test.
 * See `Validators.email` for additional information.
 */
export declare function emailValidator(control: AbstractControl): ValidationErrors | null;
/**
 * Validator that requires the length of the control's value to be greater than or equal
 * to the provided minimum length. See `Validators.minLength` for additional information.
 */
export declare function minLengthValidator(minLength: number): ValidatorFn;
/**
 * Validator that requires the length of the control's value to be less than or equal
 * to the provided maximum length. See `Validators.maxLength` for additional information.
 */
export declare function maxLengthValidator(maxLength: number): ValidatorFn;
/**
 * Validator that requires the control's value to match a regex pattern.
 * See `Validators.pattern` for additional information.
 */
export declare function patternValidator(pattern: string | RegExp): ValidatorFn;
/**
 * Function that has `ValidatorFn` shape, but performs no operation.
 */
export declare function nullValidator(control: AbstractControl): ValidationErrors | null;
export declare function toObservable(value: any): Observable<any>;
/**
 * Given the list of validators that may contain both functions as well as classes, return the list
 * of validator functions (convert validator classes into validator functions). This is needed to
 * have consistent structure in validators list before composing them.
 *
 * @param validators The set of validators that may contain validators both in plain function form
 *     as well as represented as a validator class.
 */
export declare function normalizeValidators<V>(validators: (V | Validator | AsyncValidator)[]): V[];
/**
 * Accepts a list of validators of different possible shapes (`Validator` and `ValidatorFn`),
 * normalizes the list (converts everything to `ValidatorFn`) and merges them into a single
 * validator function.
 */
export declare function composeValidators(validators: Array<Validator | ValidatorFn>): ValidatorFn | null;
/**
 * Accepts a list of async validators of different possible shapes (`AsyncValidator` and
 * `AsyncValidatorFn`), normalizes the list (converts everything to `AsyncValidatorFn`) and merges
 * them into a single validator function.
 */
export declare function composeAsyncValidators(validators: Array<AsyncValidator | AsyncValidatorFn>): AsyncValidatorFn | null;
/**
 * Merges raw control validators with a given directive validator and returns the combined list of
 * validators as an array.
 */
export declare function mergeValidators<V>(controlValidators: V | V[] | null, dirValidator: V): V[];
/**
 * Retrieves the list of raw synchronous validators attached to a given control.
 */
export declare function getControlValidators(control: AbstractControl): ValidatorFn | ValidatorFn[] | null;
/**
 * Retrieves the list of raw asynchronous validators attached to a given control.
 */
export declare function getControlAsyncValidators(control: AbstractControl): AsyncValidatorFn | AsyncValidatorFn[] | null;
/**
 * Accepts a singleton validator, an array, or null, and returns an array type with the provided
 * validators.
 *
 * @param validators A validator, validators, or null.
 * @returns A validators array.
 */
export declare function makeValidatorsArray<T extends ValidatorFn | AsyncValidatorFn>(validators: T | T[] | null): T[];
/**
 * Determines whether a validator or validators array has a given validator.
 *
 * @param validators The validator or validators to compare against.
 * @param validator The validator to check.
 * @returns Whether the validator is present.
 */
export declare function hasValidator<T extends ValidatorFn | AsyncValidatorFn>(validators: T | T[] | null, validator: T): boolean;
/**
 * Combines two arrays of validators into one. If duplicates are provided, only one will be added.
 *
 * @param validators The new validators.
 * @param currentValidators The base array of current validators.
 * @returns An array of validators.
 */
export declare function addValidators<T extends ValidatorFn | AsyncValidatorFn>(validators: T | T[], currentValidators: T | T[] | null): T[];
export declare function removeValidators<T extends ValidatorFn | AsyncValidatorFn>(validators: T | T[], currentValidators: T | T[] | null): T[];