blog_useFetch_callback.ts

// useFetch.ts
import { useState, useEffect } from "react";

interface RequestProps {
  url: RequestInfo;
  init?: RequestInit;
  processData?: (data: any) => DogImageType 
}

export type DogImageType = { message: string; status: string };

export const useFetch = ({ url, init, processData }: RequestProps) => {
  // Response state
  const [data, setData] = useState<DogImageType>();

  // Turn objects into strings for useCallback & useEffect dependencies
  const [stringifiedUrl, stringifiedInit] = [JSON.stringify(url), JSON.stringify(init)];

  // If no processing function is passed just cast the object to type T
  const processJson = processData || ((jsonBody: any) => jsonBody as DogImageType);

  useEffect(() => {
    // Define asynchronous function
    const fetchApi = async () => {
      try {
        // Fetch data from REST API
        const response = await fetch(url, init);

        if (response.status === 200) {
          // Extract json
          const rawData: any = await response.json();
          const processedData = processJson(rawData);
          setData(processedData);
        } else {
          console.error(`Error ${response.status} ${response.statusText}`);
        }
      } catch (error) {
        console.error(`Error ${error}`);
      }
    };

    // Call async function
    fetchApi();
  // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [stringifiedUrl, stringifiedInit, processJson]);

  return data;
};