How to use the React-Query library for polling data with debounce

To use the React-Query library for polling data with debounce, you can leverage the useQuery hook along with a debounce function to control the frequency of data fetching. Below is an example implementation:

First, install React-Query if you haven't already:

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npm install react-query

Then, you can create a custom hook that combines the useQuery hook with a debounce function:

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import { useState, useEffect } from 'react';
import { useQuery } from 'react-query';

// Function to debounce API calls
const debounce = (func, delay) => {
  let timeoutId;
  return (...args) => {
    clearTimeout(timeoutId);
    timeoutId = setTimeout(() => {
      func(...args);
    }, delay);
  };
};

const useDebouncedQuery = (queryKey, queryFn, debounceDelay = 500) => {
  const [queryKeyState, setQueryKeyState] = useState(queryKey);

  // Debounce the setQueryKeyState function to control the frequency of data fetching
  const debouncedSetQueryKeyState = debounce(setQueryKeyState, debounceDelay);

  useEffect(() => {
    // Reset the query key state whenever the original query key changes
    setQueryKeyState(queryKey);
  }, [queryKey]);

  return useQuery(queryKeyState, queryFn);
};

export default useDebouncedQuery;

Now, you can use this custom hook in your component to perform data polling with debounce:

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import React from 'react';
import { useDebouncedQuery } from './useDebouncedQuery';

const fetchData = async () => {
  // Replace with your actual API call to fetch data
  const response = await fetch('YOUR_API_ENDPOINT');
  if (!response.ok) {
    throw new Error('Failed to fetch data');
  }
  return response.json();
};

const MyComponent = () => {
  // Use the useDebouncedQuery hook with your query key and fetch function
  const { data, isLoading, isError } = useDebouncedQuery('data', fetchData);

  if (isLoading) return <div>Loading...</div>;
  if (isError) return <div>Error: {isError.message}</div>;

  return (
    <div>
      {/* Render your data here */}
      {data && (
        <ul>
          {data.map((item) => (
            <li key={item.id}>{item.name}</li>
          ))}
        </ul>
      )}
    </div>
  );
};

export default MyComponent;

In this example:

• We create a custom hook called useDebouncedQuery that wraps around the useQuery hook from React-Query.
• Inside the useDebouncedQuery hook, we use a debounce function to delay the execution of the setQueryKeyState function, which controls the query key for data fetching.
• We use the useDebouncedQuery hook in our component just like we would use useQuery, passing the query key and the fetch function.
• Data fetching will now be debounced, and the frequency of API calls will be controlled by the debounceDelay parameter passed to the custom hook.