Data fetching is a core aspect of dynamic and responsive applications in modern web development. Reactjs is a popular frontend library, which offers several ways to fetch and manage data.

Whether you’re building a simple app or a complex large app, It’s important to understand the various methods you can use to fetch data in react

While building a large and complex application, it is considered best practice to keep your files and folders clean and more organized way to avoid duplication and navigate easily and understandable. There are many ways but, I’m sharing with you the most popular way. Learn more about Setting up your Reactjs project structure by using atomic design pattern.

In this article, I’m going to share 5 different methods for fetching data from servers using RESTful API in reactjs:

• Fetch API
• Axios
• React Query
• SWR
• GraphQL (Apollo Client)

If you’re curious about native javascript ways, read this article on making API calls in javascript in 5 different ways.

1) Fetch API
The Fetch API is a modern & built-in javascript function for making asynchronous calls. It’s a native browser API that returns a promise. The Fetch API is built on top of javascript promises which makes handling requests much easier and cleaner to write.

Here is an example of fetching data in reactjs using Fetch API:

import React, { useEffect, useState } from "react";

export default function PostsListWrapper() {
  const [posts, setPosts] = useState([]);
  const [loading, setLoading] = useState(true);

  const getPosts = () => {
    return fetch("https://jsonplaceholder.typicode.com/posts")
      .then((response) => response.json())
      .then((data) => {
        setPosts(data);
        setLoading(false);
      })
      .catch((error) => console.error("Error: ", error));
  };

  useEffect(() => {
    getPosts();
  }, []);
  if(loading) return <p>Loading...</p>
  return (
    <section>
      <h3>Posts List</h3>
      <ul>{posts && posts?.map((item, idx) => <li key={item.id}>{item.title}</li>)}</ul>
    </section>
  );
}

2) Axios
Axios is the most popular third-party library for making asynchronous calls, based on javascript promises. Axios is simpler, faster, and much more powerful than native Fetch API, it provides control over our HTTP request.

Some of the best features I love that make it unique and powerful, such as,

• easy syntax
• creating different instances
• configure request
• playing with interceptors (middleware) to manipulate data in request and response
• retry or cancel the request
• handling errors
• and many others

In order to use axios in the react application, you need to install it as a dependency. Run the below command to install Axios:

npm i axios

Let’s see Axios in action:

import React, { useEffect, useState } from "react";
// import axios 
import axios from "axios";

// defining a base url 
const BASE_URL = "https://jsonplaceholder.typicode.com";

// creating an instance
const publicInstance = axios.create({
  baseURL: BASE_URL,
});

export default function PostsListWrapper() {
  const [posts, setPosts] = useState([]);
  const [loading, setLoading] = useState(true);

  const getPosts = async () => {
    try {
      let posts = await publicInstance({
        url: "/posts",
        method: "GET",
      });
      setLoading(false);
      setPosts(posts?.data);
    } catch (error) {
      console.log("Error: ", error);
    }
  };

  useEffect(() => {
    getPosts();
  }, []);
  if (loading) return <p>Loading...</p>;
  return (
    <section>
      <h3>Posts List</h3>
      <ul>
        {posts &&
          posts?.map((item, idx) => <li key={item.id}>{item.title}</li>)}
      </ul>
    </section>
  );
}

3) React Query
React Query is a powerful data-fetching and state management library that handles caching, automatic prefetching, providing request status (loading, success, fetching, error, and more), and many other useful features that we have to manage manually. React Query library is built by TenStack, they build multiple useful and powerful react libraries like these to make work easier and faster. If you’re interested, take a quick start guide of react-query by following this link.

You need to install the react-query as a third-party dependency to your react app to start using it. Use the below command to install react-query, and devtools to see requests in action.

npm i @tanstack/react-query @tanstack/react-query-devtools

Here is an example of how to use React Query:

import React from 'react';
import { useQuery } from 'react-query';
import axios from 'axios';

const fetchPosts = async () => {
  const { data } = await axios.get('https://jsonplaceholder.typicode.com/posts');
  return data;
};

export default function PostsListWrapper() {
  const { data, error, isLoading, isSuccess } = useQuery('posts', fetchPosts);

  if (isLoading) return <p>Loading...</p>;
  if (error) return <p>Error fetching data.</p>;

  return (
    <div>
      <h1>Posts</h1>
      {data.map((post) => (
        <div key={post.id}>
          <h2>{post.title}</h2>
          <p>{post.body}</p>
        </div>
      ))}
    </div>
  );
};

4) SWR
SWR (Stale While Revalidate) is a react hook-based library for making asynchronous calls. This library is created and maintained by Vercel (Company behind Nextjs) It focuses on cache management, revalidation, and minimal API requests.

SWR is a strategy to first return the data from the cache (stale), then send the fetch request (revalidate), and finally come up with the up-to-date data. [by, SWR]

Like react-query, it caches data, revalidates provides request status (loading, success, error). The reason it is recommended is because it is:

• lightweight
• easy syntax
• fast
• provides real-time experience
• and SSR / ISR / SSG ready

You can install SWR using the below command:

npm i swr

Let’s understand it with an example in action:

import React from 'react';
import useSWR from 'swr';

const fetcher = (url) => fetch(url).then((res) => res.json());

export default function PostsListWrapper() {
  const { data, error, isLoading } = useSWR('https://jsonplaceholder.typicode.com/posts', fetcher);

  if (isLoading) return <p>Loading...</p>;
  if (error) return <p>Error fetching data.</p>;

  return (
    <div>
      <h1>Posts</h1>
      {data.map((post) => (
        <div key={post.id}>
          <h2>{post.title}</h2>
          <p>{post.body}</p>
        </div>
      ))}
    </div>
  );
};

5) GraphQL with Apollo Client
GraphQL is becoming a new standard for making API calls. It provides efficient data handling and state management.

GraphQL on its own is a big topic, so I’ll try to keep it simple and short. GraphQL is like a query language for APIs, it means instead of RESTful API which provides all the field values and keys, GraphQL allows the frontend to request exactly the data they need in a single request. This reduces the over-fetching and unnecessary data.

Apollo Client on the other hand is a state management library that integrates with GraphQL. It is like a wrapper around GraphQL in our app which simplifies the process of fetching, caching, and managing data in client applications. It works with many different frameworks like React, Vue, Angular, and others. See the Full list of supported frameworks.

In order to use it in your react app, install the below command:

npm install @apollo/client graphql

See Apollo GraphQL in action:

import React from 'react';
import { useQuery, gql } from '@apollo/client';

const GET_POSTS = gql`
  query GetPosts {
    posts {
      id
      title
      body
    }
  }
`;

export default function PostsListWrapper() {
  const { loading, error, data } = useQuery(GET_POSTS);

  if (loading) return <p>Loading...</p>;
  if (error) return <p>Error fetching data</p>;

  return (
    <div>
      <h1>Posts</h1>
      {data.posts.map((post) => (
        <div key={post.id}>
          <h2>{post.title}</h2>
          <p>{post.body}</p>
        </div>
      ))}
    </div>
  );
};

This blog is originally posted at Programmingly.dev. Read this full article at: Here are 5 different ways to make API call in reactjs