How to use the useSWR hook for fetching and caching GraphQL data in Next.js

To use the useSWR hook for fetching and caching GraphQL data in Next.js, you can follow these steps:

1. Install required packages: Ensure that you have the necessary packages installed. You need swr for the data fetching and caching, and graphql-request for making GraphQL requests.

   bashCopy code
   npm install swr graphql-request
   

2. Create a GraphQL client: Create a GraphQL client using graphql-request. You can create a file for your client, for example, graphqlClient.js:

   javascriptCopy code
   import { GraphQLClient } from 'graphql-request';
   
   const graphQLClient = new GraphQLClient(process.env.NEXT_PUBLIC_GRAPHQL_ENDPOINT, {
     headers: {
       // You can add any headers like authentication tokens here
     },
   });
   
   export default graphQLClient;
   

   Make sure to replace process.env.NEXT_PUBLIC_GRAPHQL_ENDPOINT with your actual GraphQL endpoint.

3. Create a custom hook with useSWR: Now, you can create a custom hook that uses useSWR for fetching and caching GraphQL data. Create a file, for example, useGraphQL.js:

   javascriptCopy code
   import useSWR from 'swr';
   import graphQLClient from './graphqlClient';
   
   const fetcher = async (query) => {
     const data = await graphQLClient.request(query);
     return data;
   };
   
   const useGraphQL = (query) => {
     const { data, error } = useSWR(query, fetcher);
   
     return {
       data,
       error,
       isLoading: !data && !error,
     };
   };
   
   export default useGraphQL;
   

   This hook takes a GraphQL query as a parameter, uses useSWR to fetch and cache the data, and returns the data, error, and loading state.

4. Use the custom hook in your component: Now, you can use the useGraphQL hook in your Next.js component:

   javascriptCopy code
   import useGraphQL from '../path/to/useGraphQL';
   
   const MyComponent = () => {
     const { data, error, isLoading } = useGraphQL(`
       query {
         // Your GraphQL query here
       }
     `);
   
     if (isLoading) {
       return <p>Loading...</p>;
     }
   
     if (error) {
       return <p>Error: {error.message}</p>;
     }
   
     // Render your component with the fetched data
     return (
       <div>
         {/* Your component rendering logic using data */}
       </div>
     );
   };
   
   export default MyComponent;
   

   Replace the placeholder query in the useGraphQL call with your actual GraphQL query.

This setup allows you to easily fetch and cache GraphQL data using useSWR and graphql-request in your Next.js application.