import { ValidationError } from 'class-validator';
import { ValidationErrorMap } from './validation-error-map';
export declare type ValidationErrorHandler = (errors: ValidationError[]) => void;
export declare type ValidationErrorMapHandler = (errorMap: ValidationErrorMap) => void;
export interface ValidationErrorHandlerOptions {
    /**
     * By default, errors will be returned as a map. Setting this to `true` will pass in an
     * array of `ValidationError` to the callback instead.
     * @default false
     */
    rawErrors?: boolean;
}
/**
 * The currently set custom validation error handler, if any.
 * To set this, use `.setValidationErrorHandler()`.
 */
export declare let onValidationError: ValidationErrorHandler | undefined;
/**
 * Register a callback to run whenever a validation fails.
 * @param handler The callback that will receive a map of validation errors.
 * @param opts Options
 */
export declare function setValidationErrorHandler(handler: ValidationErrorMapHandler, opts?: ValidationErrorHandlerOptions & {
    rawErrors?: false;
}): void;
/**
 * Register a callback to run whenever a validation fails.
 * @param handler The callback that will receive an array of validation errors.
 * @param opts Options
 */
export declare function setValidationErrorHandler(handler: ValidationErrorHandler, opts: ValidationErrorHandlerOptions & {
    rawErrors: true;
}): void;
/**
 * Unregisters the callback to run when a validation fails, and uses the default behavior.
 */
export declare function clearValidationErrorHandler(): void;