import { EventEmitter, OnChanges, OnDestroy } from '@angular/core';
import { AsyncValidatorFn, ControlContainer, ControlValueAccessor, Validator, ValidatorFn } from '@angular/forms';
import { Path } from '../crnk.expression';
import { CrnkControl } from './crnk.expression.form.model.base';
/**
 * Allows to bind expressions of type {link Expression} to expectForm controls. The directive is very similar to
 * NgModel, but allows to bind an expression instead of a generic object. The advantage is that an expression
 * can hold both
 */
export declare class FormExpressionDirective extends CrnkControl implements OnChanges, OnDestroy {
    pathModel: Path<any>;
    name: string;
    arbFormExpressionChange: EventEmitter<{}>;
    /**
     * NOTE that in contract to NgModel we do not use @Host for parent. This would enforce that the
     * components are direct children of the forms component. TODO investigate whether there is
     * any better solutions (maybe something similar to FormGroup). It does not seem like it is possible
     * to expose an existing ControlContainer again with @Component.providers as it would lead to a circular
     * dependency (there is no provider for children only, but itself as well).
     */
    constructor(parent: ControlContainer, validators: Array<Validator | ValidatorFn>, asyncValidators: Array<Validator | AsyncValidatorFn>, valueAccessors: ControlValueAccessor[]);
    ngOnDestroy(): void;
    readonly path: string[];
    readonly formDirective: any;
    viewToModelUpdate(newValue: any): void;
    protected _setUpControl(): void;
    private _checkForErrors();
    private _checkParentType();
}