interaktive-systeme/hooks/useFetch.ts

import { Query } from "expo-sqlite";
import { useEffect, useState } from "react";
import { executeQuery } from "../services/database";

const useFetch = (query: Query) => {

    const [fetchState, setFetchState] = useState<{
        data: {[column: string]: any;}[];
        isLoading: boolean;
        isEmptyResult: boolean | undefined;
    }>({
        data: [],
        isLoading: false,
        isEmptyResult: undefined
    });

    const setIsLoading = (isLoading: boolean) => {
        setFetchState((prevState) => ( {...prevState, isLoading} ));
    }

    const setData = (data: {[column: string]: any;}[]) => {
        setFetchState((prevState) => ( {...prevState, data} ));
    }

    const setIsEmptyResult = (isEmptyResult: boolean) => {
        setFetchState((prevState) => ( {...prevState, isEmptyResult} ));
    }


    const reFetch = () => {
        setIsLoading(true);
        executeQuery(query).then((result) => {
            if("rows" in result[0]) {
                setData(result[0]["rows"]);
                if(result[0]["rows"].length == 0){
                    setIsEmptyResult(true);
                }
            }
        }).catch((error: any) => {
            console.error("Fetching data from database has failed: ", error);
        }).then(() => {
            setIsLoading(false);
        });
    }

    useEffect(() => {
        reFetch();
    }, [])

    return {...fetchState, reFetch};
}

export default useFetch;