import { Catalog } from "../../settings/Catalog";
import { UrlFetcher } from "./UrlFetcher";
export interface SparqlHandlerIfc {
    executeSparql(sparql: string, callback: (data: any) => void, errorCallback?: (error: any) => void): void;
}
export declare class SparqlHandlerFactory {
    protected lang: string;
    protected localCacheDataTtl: any;
    protected extraHeaders: Map<string, string>;
    protected customizedSparqlHandler: SparqlHandlerIfc;
    protected catalog?: Catalog;
    constructor(lang: string, localCacheDataTtl: any, extraHeaders: Map<string, string>, customizedSparqlHandler?: SparqlHandlerIfc, catalog?: Catalog);
    buildSparqlHandler(endpoints: string[]): SparqlHandlerIfc;
}
/**
 * Executes a SPARQL query against a remote endpoint at a known URL
 */
export declare class EndpointSparqlHandler implements SparqlHandlerIfc {
    urlFetcher: UrlFetcher;
    sparqlEndpointUrl: any;
    constructor(urlFetcher: UrlFetcher, sparqlEndpointUrl: any);
    buildUrl(sparql: string): string;
    buildParameters(sparql: string): string;
    executeSparqlPost(sparql: string, callback: (data: {}) => void, errorCallback?: (error: any) => void): void;
    executeSparqlGet(sparql: string, callback: (data: {}) => void, errorCallback?: (error: any) => void): void;
    executeSparql(sparql: string, callback: (data: {}) => void, errorCallback?: (error: any) => void): void;
}
/**
 * Executes a SPARQL query against multiple endpoints
 * and returns the results merged in a single result set
 * with an extra column to express the source
 */
export declare class MultipleEndpointSparqlHandler implements SparqlHandlerIfc {
    urlFetcher: UrlFetcher;
    catalog: Catalog;
    addExtraEndpointColumn: boolean;
    extraColumnName: string;
    lang: string;
    constructor(urlFetcher: UrlFetcher, catalog: Catalog, lang: string);
    executeSparql(sparql: string, callback: (data: any) => void, errorCallback?: (error: any) => void): void;
}