react-firehooks/lib/internal/useListen.js

Lightweight dependency-free collection of React hooks for Firebase

import { useEffect, useMemo } from "react";
import { useLoadingValue } from "./useLoadingValue.js";
import { useStableValue } from "./useStableValue.js";
import { usePrevious } from "./usePrevious.js";
/**
 * @internal
 */
export function useListen(reference, onChange, isEqual, initialState) {
    const { error, loading, setLoading, setError, setValue, value } = useLoadingValue(reference === undefined ? undefined : initialState);
    const stableRef = useStableValue(reference !== null && reference !== void 0 ? reference : undefined, isEqual);
    const previousRef = usePrevious(stableRef);
    // set state when ref changes
    useEffect(() => {
        if (stableRef === previousRef) {
            return;
        }
        if (stableRef === undefined) {
            setValue();
        }
        else {
            setLoading();
        }
    }, [previousRef, setLoading, setValue, stableRef]);
    // subscribe to changes
    useEffect(() => {
        if (stableRef === undefined) {
            return;
        }
        const unsubscribe = onChange(stableRef, setValue, setError);
        return () => unsubscribe();
    }, [onChange, setError, setValue, stableRef]);
    return useMemo(() => [value, loading, error], [value, loading, error]);
}