StackPuz

Posted on Sep 19 • Originally published at blog.stackpuz.com on Sep 16

Building a React CRUD App with an Express API

#react #express #crud

Developing a CRUD application is a key skill in web development. In this tutorial, we'll show you how to build a robust CRUD app with React as the user interface and an Express API as the backend service, providing a full-stack solution for managing data.

Prerequisites

Node.js
MySQL

Setup React project

npm create vite@4.4.0 view -- --template react
cd view
npm install react-router-dom@5 axios

React project structure

├─ index.html
├─ public
│  └─ css
│     └─ style.css
└─ src
   ├─ components
   │  └─ product
   │     ├─ Create.jsx
   │     ├─ Delete.jsx
   │     ├─ Detail.jsx
   │     ├─ Edit.jsx
   │     ├─ Index.jsx
   │     └─ Service.js
   ├─ history.js
   ├─ http.js
   ├─ main.jsx
   ├─ router.jsx
   └─ App.jsx

React project files

main.jsx

import React from 'react'
import ReactDOM from 'react-dom/client'
import App from './App'

ReactDOM.createRoot(document.getElementById('root')).render(
  <App />
)

The main.jsx file is the entry point for a React app. It imports React, ReactDOM, and the App component. The ReactDOM.createRoot method is used to render the App component into the HTML element with the ID root.

App.jsx

import React, { useState, useEffect } from 'react'
import { Router, Link } from 'react-router-dom'
import history from './history'
import Route from './router'

export default function App() {
  return (
    <Router history={history}>
      <Route />
    </Router>
  )
}

The App.jsx file sets up routing for a React app. The App component wraps the application in a Router using the custom history, and renders the Route component for handling routes.

history.js

import { createBrowserHistory } from 'history'

export default createBrowserHistory()

The history.js file exports a custom browser history object created with createBrowserHistory for managing navigation in a React app.

router.jsx

import React, { Suspense, lazy } from 'react'
import { Switch, Route, Redirect } from 'react-router-dom'

export default function AppRoute(props) {
  return (
    <Suspense fallback={''}>
      <Switch>
        <Route path="/" component={(p) => <Redirect to="/product" /> } exact />
        <Route path="/product" component={lazy(() => import('./components/product/Index'))} exact />
        <Route path="/product/create" component={lazy(() => import('./components/product/Create'))} exact />
        <Route path="/product/:id/" component={lazy(() => import('./components/product/Detail'))} exact />
        <Route path="/product/edit/:id/" component={lazy(() => import('./components/product/Edit'))} exact />
        <Route path="/product/delete/:id/" component={lazy(() => import('./components/product/Delete'))} exact />
      </Switch>
    </Suspense>
  )
}

The router.jsx file sets up routing for a React app with lazy-loaded components. It uses Suspense to handle loading status, and Switch to define routes. The root path redirects to /product, and specific routes handle product-related pages like create, detail, edit, and delete.

http.js

import axios from 'axios'

let http = axios.create({
  baseURL: 'http://localhost:8000/api',
  headers: {
    'Content-type': 'application/json'
  }
})

export default http

The http.js file configures and exports an Axios instance with a centralized base URL, which is a standard practice for managing API endpoints and default headers set to application/json.

Create.jsx

import React, { useState, useEffect } from 'react'
import { Link } from 'react-router-dom'
import Service from './Service'

export default function ProductCreate(props) {

  const [product, setProduct] = useState({})

  function create(e) {
    e.preventDefault()
    Service.create(product).then(() => {
      props.history.push('/product')
    }).catch((e) => {
      alert(e.response.data)
    })
  }

  function onChange(e) {
    let data = { ...product }
    data[e.target.name] = e.target.value
    setProduct(data)
  }

  return (
    <div className="container">
      <div className="row">
        <div className="col">
          <form method="post" onSubmit={create}>
            <div className="row">
              <div className="mb-3 col-md-6 col-lg-4">
                <label className="form-label" htmlFor="product_name">Name</label>
                <input id="product_name" name="name" className="form-control" onChange={onChange} value={product.name ?? '' } maxLength="50" />
              </div>
              <div className="mb-3 col-md-6 col-lg-4">
                <label className="form-label" htmlFor="product_price">Price</label>
                <input id="product_price" name="price" className="form-control" onChange={onChange} value={product.price ?? '' } type="number" />
              </div>
              <div className="col-12">
                <Link className="btn btn-secondary" to="/product">Cancel</Link>
                <button className="btn btn-primary">Submit</button>
              </div>
            </div>
          </form>
        </div>
      </div>
    </div>
  )
}

The create.jsx file defines a ProductCreate component for adding a new product. It uses useState to manage form data, and handles form submission with create(e) that sends data via Service.create and redirects on success. The form includes fields for product name and price, with a cancel link and submit button.

Delete.jsx

import React, { useState, useEffect } from 'react'
import { Link } from 'react-router-dom'
import Service from './Service'

export default function ProductDelete(props) {

  const [product, setProduct] = useState({})

  useEffect(() => {
    get()
  }, [props.match.params.id])

  function get() {
    return Service.delete(props.match.params.id).then(response => {
      setProduct(response.data)
    }).catch(e => {
      alert(e.response.data)
    })
  }

  function remove(e) {
    e.preventDefault()
    Service.delete(props.match.params.id, product).then(() => {
      props.history.push('/product')
    }).catch((e) => {
      alert(e.response.data)
    })
  }

  return (
    <div className="container">
      <div className="row">
        <div className="col">
          <form method="post" onSubmit={remove}>
            <div className="row">
              <div className="mb-3 col-md-6 col-lg-4">
                <label className="form-label" htmlFor="product_id">Id</label>
                <input readOnly id="product_id" name="id" className="form-control" value={product.id ?? '' } type="number" required />
              </div>
              <div className="mb-3 col-md-6 col-lg-4">
                <label className="form-label" htmlFor="product_name">Name</label>
                <input readOnly id="product_name" name="name" className="form-control" value={product.name ?? '' } maxLength="50" />
              </div>
              <div className="mb-3 col-md-6 col-lg-4">
                <label className="form-label" htmlFor="product_price">Price</label>
                <input readOnly id="product_price" name="price" className="form-control" value={product.price ?? '' } type="number" />
              </div>
              <div className="col-12">
                <Link className="btn btn-secondary" to="/product">Cancel</Link>
                <button className="btn btn-danger">Delete</button>
              </div>
            </div>
          </form>
        </div>
      </div>
    </div>
  )
}

The Delete.jsx file defines a ProductDelete component for deleting a product. It fetches product details using Service.delete and displays them in a read-only form. The component uses useEffect to load product data based on the product ID from the route parameters. The remove(e) function handles deletion and redirects to /product upon success.

Detail.jsx

import React, { useState, useEffect } from 'react'
import { Link } from 'react-router-dom'
import Service from './Service'

export default function ProductDetail(props) {

  const [product, setProduct] = useState({})

  useEffect(() => {
    get()
  }, [props.match.params.id])

  function get() {
    return Service.get(props.match.params.id).then(response => {
      setProduct(response.data)
    }).catch(e => {
      alert(e.response.data)
    })
  }

  return (
    <div className="container">
      <div className="row">
        <div className="col">
          <form method="post">
            <div className="row">
              <div className="mb-3 col-md-6 col-lg-4">
                <label className="form-label" htmlFor="product_id">Id</label>
                <input readOnly id="product_id" name="id" className="form-control" value={product.id ?? '' } type="number" required />
              </div>
              <div className="mb-3 col-md-6 col-lg-4">
                <label className="form-label" htmlFor="product_name">Name</label>
                <input readOnly id="product_name" name="name" className="form-control" value={product.name ?? '' } maxLength="50" />
              </div>
              <div className="mb-3 col-md-6 col-lg-4">
                <label className="form-label" htmlFor="product_price">Price</label>
                <input readOnly id="product_price" name="price" className="form-control" value={product.price ?? '' } type="number" />
              </div>
              <div className="col-12">
                <Link className="btn btn-secondary" to="/product">Back</Link>
                <Link className="btn btn-primary" to={`/product/edit/${product.id}`}>Edit</Link>
              </div>
            </div>
          </form>
        </div>
      </div>
    </div>
  )
}

The Detail.jsx file defines a ProductDetail component that displays details of a product. It fetches product data using Service.get based on the product ID from the route parameters and displays it in a read-only form, and provides links to go back to the product list or to edit the product.

Edit.jsx

import React, { useState, useEffect } from 'react'
import { Link } from 'react-router-dom'
import Service from './Service'

export default function ProductEdit(props) {

  const [product, setProduct] = useState({})

  useEffect(() => {
    get()
  }, [props.match.params.id])

  function get() {
    return Service.edit(props.match.params.id).then(response => {
      setProduct(response.data)
    }).catch(e => {
      alert(e.response.data)
    })
  }

  function edit(e) {
    e.preventDefault()
    Service.edit(props.match.params.id, product).then(() => {
      props.history.push('/product')
    }).catch((e) => {
      alert(e.response.data)
    })
  }

  function onChange(e) {
    let data = { ...product }
    data[e.target.name] = e.target.value
    setProduct(data)
  }

  return (
    <div className="container">
      <div className="row">
        <div className="col">
          <form method="post" onSubmit={edit}>
            <div className="row">
              <div className="mb-3 col-md-6 col-lg-4">
                <label className="form-label" htmlFor="product_id">Id</label>
                <input readOnly id="product_id" name="id" className="form-control" onChange={onChange} value={product.id ?? '' } type="number" required />
              </div>
              <div className="mb-3 col-md-6 col-lg-4">
                <label className="form-label" htmlFor="product_name">Name</label>
                <input id="product_name" name="name" className="form-control" onChange={onChange} value={product.name ?? '' } maxLength="50" />
              </div>
              <div className="mb-3 col-md-6 col-lg-4">
                <label className="form-label" htmlFor="product_price">Price</label>
                <input id="product_price" name="price" className="form-control" onChange={onChange} value={product.price ?? '' } type="number" />
              </div>
              <div className="col-12">
                <Link className="btn btn-secondary" to="/product">Cancel</Link>
                <button className="btn btn-primary">Submit</button>
              </div>
            </div>
          </form>
        </div>
      </div>
    </div>
  )
}

The Edit.jsx file defines a ProductEdit component for updating product details. It fetches the current product data using Service.edit and populates a form with this data. The form allows users to modify the product's name and price. On form submission, the edit(e) function updates the product via Service.edit and redirects to the product list on success.

Index.jsx

import React, { useState, useEffect } from 'react'
import { Link } from 'react-router-dom'
import Service from './Service'

export default function ProductIndex(props) {

  const [products, setProducts] = useState([])

  useEffect(() => {
    get()
  }, [props.location])

  function get() {
    Service.get().then(response => {
      setProducts(response.data)
    }).catch(e => {
      alert(e.response.data)
    })
  }

  return (
    <div className="container">
      <div className="row">
        <div className="col">
          <table className="table table-striped table-hover">
            <thead>
              <tr>
                <th>Id</th>
                <th>Name</th>
                <th>Price</th>
                <th>Actions</th>
              </tr>
            </thead>
            <tbody>
              {products.map((product, index) =>
              <tr key={index}>
                <td className="text-center">{product.id}</td>
                <td>{product.name}</td>
                <td className="text-center">{product.price}</td>
                <td className="text-center">
                  <Link className="btn btn-secondary" to={`/product/${product.id}`} title="View"><i className="fa fa-eye"></i></Link>
                  <Link className="btn btn-primary" to={`/product/edit/${product.id}`} title="Edit"><i className="fa fa-pencil"></i></Link>
                  <Link className="btn btn-danger" to={`/product/delete/${product.id}`} title="Delete"><i className="fa fa-times"></i></Link>
                </td>
              </tr>
              )}
            </tbody>
          </table>
          <Link className="btn btn-primary" to="/product/create">Create</Link>
        </div>
      </div>
    </div>
  )
}

The Index.jsx file defines a ProductIndex component that displays a list of products in a table. It fetches product data using Service.get and updates the list on component mount. The table shows product ID, name, and price, with action buttons for viewing, editing, and deleting each product. It also includes a link to create a new product.

Service.js

import http from '../../http'

export default {
  get(id) {
    if (id) {
      return http.get(`/products/${id}`)
    }
    else {
      return http.get('/products' + location.search)
    }
  },
  create(data) {
    if (data) {
      return http.post('/products', data)
    }
    else {
      return http.get('/products/create')
    }
  },
  edit(id, data) {
    if (data) {
      return http.put(`/products/${id}`, data)
    }
    else {
      return http.get(`/products/${id}`)
    }
  },
  delete(id, data) {
    if (data) {
      return http.delete(`/products/${id}`)
    }
    else {
      return http.get(`/products/${id}`)
    }
  }
}

The Service.js file defines API methods for handling product operations. It uses an http instance for making requests:

get(id) Retrieves a single product by ID or all products if no ID is provided.
create(data) Creates a new product with the provided data or fetches the creation form if no data is provided.
edit(id, data) Updates a product by ID with the provided data or fetches the product details if no data is provided.
delete(id, data) Deletes a product by ID or fetches the product details if no data is provided.

style.css

.container {
  margin-top: 2em;
}

.btn {
  margin-right: 0.25em;
}

The CSS adjusts the layout by adding space above the container and spacing out buttons horizontally.

index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width,initial-scale=1">
  <link href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap/5.3.3/css/bootstrap.min.css" rel="stylesheet">
  <link href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.0/css/all.min.css" rel="stylesheet">
  <link href="/css/style.css" rel="stylesheet">
</head>
<body>
  <div id="root"></div>
  <script type="module" src="/src/main.jsx"></script>
</body>
</html>

The HTML serves as the main entry point for an React application, including Bootstrap for styling, Font Awesome for icons, It features a div with the ID root where the React app will render.

Setup Express API project

npm install express mysql2 sequelize cors

Create a testing database named "example" and execute the database.sql file to import the table and data.

Express API Project structure

├─ config.js
├─ index.js
├─ router.js
├─ db.js
├─ controllers
│  └─ ProductController.js
└─ models
   └─ Product.js

Express API Project files

config.js

module.exports = {
  host: '127.0.0.1',
  port: 3306,
  user: 'root',
  password: '',
  database: 'example',
  dialect: 'mysql'
}

This file holds the configuration details for connecting to the database.

db.js

const Sequelize = require('sequelize')
const config = require('./config')

module.exports = new Sequelize(config.database, config.user, config.password, {
  host: config.host,
  port: config.port,
  dialect: config.dialect,
  define: {
    timestamps: false,
    freezeTableName: true
  }
})

This db.js file initializes and exports a Sequelize instance using configuration details from a config.js file. It connects to the database with specified credentials and options, disabling automatic timestamps and preserving table names as defined.

router.js

const express = require('express')
const product = require('./controllers/ProductController.js')

module.exports = express.Router().use('/products', express.Router()
  .get('/', product.getProducts)
  .get('/:id', product.getProduct)
  .post('/', product.createProduct)
  .put('/:id', product.updateProduct)
  .delete('/:id', product.deleteProduct)
)

This router.js file configures Express routes for product management. It exports a router that handles GET, POST, PUT, and DELETE requests under the /products path, linking each route to a corresponding method in the ProductController.

index.js

const express = require('express')
const cors = require('cors')
const router = require('./router.js')

const app = express()
app.use(cors())
app.use(express.json())
app.use('/api', router)
app.listen(8000)

This index.js file sets up an Express server. The app is configured to use CORS for handling cross-origin requests and to parse JSON request bodies. The router is mounted on the /api path, handling all API routes defined in the router module. Finally, the server listens for incoming connections on port 8000.

product.js

const Sequelize = require('sequelize')
const db = require('../db')

module.exports = db.define('Product', {
  id: {
    type: Sequelize.INTEGER,
    primaryKey: true,
    autoIncrement: true
  },
  name: Sequelize.STRING,
  price: Sequelize.DECIMAL
})

This product.js file defines a Sequelize model for a Product entity. The model is defined with three fields: id, (a primary key that auto-increments), name, price.The model is then exported for use in other parts of the application.

ProductController.js

const Product = require('../models/Product')

exports.getProducts = async (req, res) => {
  let products = await Product.findAll()
  res.send(products)
}

exports.getProduct = async (req, res) => {
  let product = await Product.findByPk(req.params.id)
  res.send(product)
}

exports.createProduct = async (req, res) => {
  let product = { ...req.body }
  let created = await Product.create(product)
  res.send(created)
}

exports.updateProduct = async (req, res) => {
  let product = { ...req.body }
  await Product.update(product, { where: { id: req.params.id } })
  let updated = await Product.findByPk(req.params.id)
  res.send(updated)
}

exports.deleteProduct = async (req, res) => {
  await Product.destroy({ where: { id: req.params.id } })
  res.end()
}

The ProductController.js file defines several asynchronous handler functions for managing Product entities in a Express API application using Sequelize.

getProducts Retrieves and sends a list of all products.
getProduct Fetches and sends a single product based on its ID.
createProduct Creates a new product from the request body.
updateProduct Updates an existing product with the data from the request body.
deleteProduct Deletes a product by its ID.

Run projects

Run React project

npm run dev

Run Express API project

node index.js

Open the web browser and goto http://localhost:5173

You will find this product list page.

Testing

Click the "View" button to see the product details page.

Click the "Edit" button to modify the product and update its details.

Click the "Submit" button to save the updated product details.

Click the "Create" button to add a new product and input its details.

Click the "Submit" button to save the new product.

Click the "Delete" button to remove the previously created product.

Click the "Delete" button to confirm the removal of this product.

Conclusion

In conclusion, we have learned how to create a basic React project using JSX syntax to build views and routing, while setting up an Express API server as the backend. By utilizing Sequelize for database operations, we've developed a dynamic front-end that seamlessly interacts with a powerful backend, providing a strong foundation for modern, full-stack web applications.

Source code: https://github.com/stackpuz/Example-CRUD-React-18-Express-4

Create a React CRUD App in Minutes: https://stackpuz.com

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