@shopify/react-graphql/build/ts/hooks/background-query.js

Tools for creating type-safe and asynchronous GraphQL components for React

import { useEffect, useRef, useCallback } from 'react';
import useApolloClient from './apollo-client';
export function useBackgroundQuery(load, options) {
    const client = useApolloClient();
    const lastClient = useRef(client);
    const lastOptions = useRef(options);
    const serializedOptions = JSON.stringify(options);
    const lastSerializedOptions = useRef(serializedOptions);
    const subscription = useRef(null);
    const polling = useRef(Boolean(options && options.pollInterval));
    if (subscription.current != null &&
        (lastClient.current !== client ||
            lastSerializedOptions.current !== serializedOptions)) {
        subscription.current.unsubscribe();
        subscription.current = null;
    }
    lastClient.current = client;
    lastOptions.current = options;
    lastSerializedOptions.current = serializedOptions;
    useEffect(() => () => {
        if (subscription.current) {
            subscription.current.unsubscribe();
            subscription.current = null;
        }
    }, []);
    return useCallback(async () => {
        if (subscription.current) {
            return;
        }
        const query = await load();
        if (query == null || query instanceof Error) {
            return;
        }
        const observableQuery = lastClient.current.watchQuery(Object.assign({ query, fetchPolicy: 'network-only' }, lastOptions.current));
        const unsubscribe = () => {
            if (polling.current || subscription.current == null) {
                return;
            }
            subscription.current.unsubscribe();
            subscription.current = null;
        };
        subscription.current = observableQuery.subscribe(unsubscribe, unsubscribe);
    }, [load]);
}