import { LoggerService } from '@sowatech/shared/logger';
import { Subject } from 'rxjs';
import { FilterItem, FilterOperator } from './ds-dtos.model';
import * as i0 from "@angular/core";
export declare class FilterHelper {
    private loggerService;
    constructor(loggerService: LoggerService);
    private filterStrategies;
    private items;
    onFilterItems: Subject<FilterItem[]>;
    get filterItems(): Array<FilterItem>;
    private getItemByFieldNames;
    getFirstValueByFieldname(fieldnames: string[], filterOperator: FilterOperator): string | null;
    clear(): void;
    add(filterItems: Array<FilterItem>): any;
    add(filterItem: FilterItem): any;
    set(filterItems: Array<FilterItem>): any;
    set(filterItem: FilterItem): any;
    execute(dataSourceBackup: Array<any>, dataSource: Array<any>): void;
    static ɵfac: i0.ɵɵFactoryDeclaration<FilterHelper, never>;
    static ɵprov: i0.ɵɵInjectableDeclaration<FilterHelper>;
}