Building a CRUD Application with Next.js and an External API | Updated 2024

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Next.js is a popular React framework that enables server-side rendering and static site generation. In this article, we’ll walk through creating a basic CRUD (Create, Read, Update, Delete) application using Next.js and an external API. For simplicity, we’ll use the JSONPlaceholder API as our external data source.

Steps for CRUD in Next.js with axios

Step 1: Setting Up the Project

First, let’s set up a new Next.js project.

Initialize a New Project

npx create-next-app@latest nextjs-crud
cd nextjs-crud

Install Axios

We’ll use Axios for making HTTP requests.

npm install axios

Step 2: Creating API Service

Create a service to handle API requests. Create a file named api.js inside a new services directory.

// services/api.js
import axios from 'axios';

const API_URL = 'https://jsonplaceholder.typicode.com/posts';

export const getPosts = async () => {
  const response = await axios.get(API_URL);
  return response.data;
};

export const getPost = async (id) => {
  const response = await axios.get(`${API_URL}/${id}`);
  return response.data;
};

export const createPost = async (post) => {
  const response = await axios.post(API_URL, post);
  return response.data;
};

export const updatePost = async (id, post) => {
  const response = await axios.put(`${API_URL}/${id}`, post);
  return response.data;
};

export const deletePost = async (id) => {
  await axios.delete(`${API_URL}/${id}`);
};

Step 3: Creating Pages and Components

Displaying All Posts

Create a page to list all posts.

// pages/index.js
import { useEffect, useState } from 'react';
import { getPosts } from '../services/api';
import Link from 'next/link';

const HomePage = () => {
  const [posts, setPosts] = useState([]);

  useEffect(() => {
    const fetchPosts = async () => {
      const data = await getPosts();
      setPosts(data);
    };
    fetchPosts();
  }, []);

  return (
    <div>
      <h1>Posts</h1>
      <Link href="/create">
        <a>Create New Post</a>
      </Link>
      <ul>
        {posts.map((post) => (
          <li key={post.id}>
            <Link href={`/post/${post.id}`}>
              <a>{post.title}</a>
            </Link>
          </li>
        ))}
      </ul>
    </div>
  );
};

export default HomePage;

Displaying a Single Post

Create a page to display a single post.

// pages/post/[id].js
import { useRouter } from 'next/router';
import { getPost, deletePost } from '../../services/api';
import { useState, useEffect } from 'react';
import Link from 'next/link';

const PostPage = () => {
  const router = useRouter();
  const { id } = router.query;
  const [post, setPost] = useState(null);

  useEffect(() => {
    if (id) {
      const fetchPost = async () => {
        const data = await getPost(id);
        setPost(data);
      };
      fetchPost();
    }
  }, [id]);

  const handleDelete = async () => {
    await deletePost(id);
    router.push('/');
  };

  if (!post) return <div>Loading...</div>;

  return (
    <div>
      <h1>{post.title}</h1>
      <p>{post.body}</p>
      <Link href={`/edit/${id}`}>
        <a>Edit</a>
      </Link>
      <button onClick={handleDelete}>Delete</button>
      <Link href="/">
        <a>Back to Posts</a>
      </Link>
    </div>
  );
};

export default PostPage;

Creating a New Post

Create a page for adding a new post.

// pages/create.js
import { useState } from 'react';
import { createPost } from '../services/api';
import { useRouter } from 'next/router';

const CreatePostPage = () => {
  const [title, setTitle] = useState('');
  const [body, setBody] = useState('');
  const router = useRouter();

  const handleSubmit = async (e) => {
    e.preventDefault();
    await createPost({ title, body });
    router.push('/');
  };

  return (
    <div>
      <h1>Create New Post</h1>
      <form onSubmit={handleSubmit}>
        <div>
          <label>Title</label>
          <input
            type="text"
            value={title}
            onChange={(e) => setTitle(e.target.value)}
            required
          />
        </div>
        <div>
          <label>Body</label>
          <textarea
            value={body}
            onChange={(e) => setBody(e.target.value)}
            required
          ></textarea>
        </div>
        <button type="submit">Create</button>
      </form>
    </div>
  );
};

export default CreatePostPage;

Editing a Post

Create a page for editing an existing post.

// pages/edit/[id].js
import { useRouter } from 'next/router';
import { useState, useEffect } from 'react';
import { getPost, updatePost } from '../../services/api';

const EditPostPage = () => {
  const router = useRouter();
  const { id } = router.query;
  const [title, setTitle] = useState('');
  const [body, setBody] = useState('');

  useEffect(() => {
    if (id) {
      const fetchPost = async () => {
        const data = await getPost(id);
        setTitle(data.title);
        setBody(data.body);
      };
      fetchPost();
    }
  }, [id]);

  const handleSubmit = async (e) => {
    e.preventDefault();
    await updatePost(id, { title, body });
    router.push(`/post/${id}`);
  };

  return (
    <div>
      <h1>Edit Post</h1>
      <form onSubmit={handleSubmit}>
        <div>
          <label>Title</label>
          <input
            type="text"
            value={title}
            onChange={(e) => setTitle(e.target.value)}
            required
          />
        </div>
        <div>
          <label>Body</label>
          <textarea
            value={body}
            onChange={(e) => setBody(e.target.value)}
            required
          ></textarea>
        </div>
        <button type="submit">Update</button>
      </form>
    </div>
  );
};

export default EditPostPage;

Step 4: Running the Application

Start the Next.js development server.

npm run dev

Open your browser and navigate to http://localhost:3000 to see your CRUD application in action.

Conclusion

In this article, we’ve built a simple CRUD application using Next.js and an external API. This example can be expanded and customized to fit more complex requirements, but it serves as a solid foundation for understanding how to integrate Next.js with external APIs for full-stack development.

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Building a CRUD Application with Next.js – FAQs