import { EntitySubscriberInterface, InsertEvent, UpdateEvent } from 'typeorm';
/**
 * This is a generic subscriber for events. It provides an afterLoad
 * event handler to remove null values from entity in case user can't directly set them with `null`
 * Example:
 *    `custom` data is nullable in DB because it's optional,
 *    but it can't be set as null by the end-user directly. So, to avoid this inconsistency
 *    we need to omit this field in GET operations.
 */
export declare abstract class EntitySubscriber<TEntity> implements EntitySubscriberInterface<TEntity> {
    private cls;
    private readonly nullableFields;
    constructor(cls: new (...args: any) => TEntity, nullableFields: string[]);
    listenTo(): any;
    afterLoad(entity: TEntity): void;
    beforeUpdate(event: UpdateEvent<TEntity>): void;
    beforeInsert(event: InsertEvent<TEntity>): void;
}