/// <reference types="react" />
import { ContentfulDataSource } from '../../dataSource';
/**
 * Executes a query function against the dataSource and returns the result.
 *
 * The result is in one of 3 states:
 * 1. Loading, no result available
 * 2. Error, result may or may not be available
 * 3. Success, result is available
 *
 * Re-running the query does not set "loading: true", the loading flag is intended
 * for the initial load use case.
 *
 * Example:
 * const [result, { loading, error, refreshing }, refresh] = useQuery(async (dataSource) => { ... })
 */
export type UseQueryResult<TResult> = [
    TResult | undefined,
    UseQueryState,
    () => Promise<void>
];
export interface UseQueryState {
    /**
     * The error that occurred during the last query.  This is undefined if the query was successful.
     */
    error?: Error;
    /**
     * True if the initial query that is run when the component is mounted is still in progress.
     */
    loading: boolean;
    /**
     * True if the "refresh" method was invoked by the component and the query has not yet completed.
     *
     * This is useful for showing a "refreshing" indicator in the UI in response to a user action that
     * triggered the "refresh" method.
     */
    refreshing: boolean;
    /**
     * True if the dataSource has been updated and the query has not yet been re-run.
     *
     * If autoUpdate is true (or undefined), this will only be true for the time it takes the async query to resolve.
     */
    stale: boolean;
}
export interface UseQueryOptions {
    /**
     * If true, the query will be re-run whenever the dataSource is updated.
     * Otherwise the stale indicator will be set to true.
     *
     * Defaults to true.
     */
    autoRefresh?: boolean;
}
/**
 * Executes an arbitrary query against the dataSource.  The result is stored in the
 * first element of the returned tuple.
 *
 * The result will be undefined until the query successfully completes the first time.
 * The query will be rerun whenever the dataSource is updated or one of the "deps" changes.
 */
export declare function useQuery<TResult>(
/**
 * The query to execute.  The return value is stored in the first element of the returned tuple.
 */
query: (dataSource: ContentfulDataSource) => Promise<TResult> | TResult, options?: UseQueryOptions, 
/**
 * Control when the query will be re-run.  The query is always re-run when the dataSource is updated.
 */
deps?: React.DependencyList): UseQueryResult<TResult>;
export declare function isDependencyList(value: any): value is React.DependencyList;