React.js + Python + MongoDB CRUD application example

Hello everyone, today we will learn how to develop a  web application that is a basic User Management Application using MongoDB, React.js, Python, and Flask.GitHub repository link is provided at the end of this tutorial. You can download the source code.

More Related Topics,

Architecture:

We’re gonna build the application with the following architecture:

After completing this tutorial what we will build?

We will build a full-stack web application that is a basic User Management Application with CRUD features:

    • Create User
    • List User
    • Update User
    • Delete User
    • View User

Following is the screenshot of our application -

-View all Users:


-Add a User:


-Update User:


-View User

We divided this tutorial into two parts. 

PART 1 - Rest APIs Development using Python and Flask

PART 2 - UI development using React.js   


PART 1 - Rest APIs Development using Python and Flask

These are APIs that Python Flask App will export: 

  1. GET all User's        :     /api/v1/users
  2. GET User by ID     :     /api/v1/users/{_id}
  3. POST User             :     /api/v1/users 
  4. PUT User               :     /api/v1/users/{_id} 
  5. DELETE User       :     /api/v1/users/{_id}

Back end project structure:


In this project, I'm using flask, flask_cors & pymongo dependencies, use the following command to install the same.
pip install flask flask_cors pymongo

database.yaml
uri: 'mongodb://localhost:27017/knf-dev'


app.py
from flask import Flask, render_template, request, jsonify
from pymongo import MongoClient
from bson.objectid import ObjectId
from flask_cors import CORS
import yaml

app = Flask(__name__)
config = yaml.load(open('database.yaml'))
client = MongoClient(config['uri'])
# db = client.lin_flask
db = client['knf-dev']
CORS(app)

@app.route('/')
def index():
return render_template('home.html')

@app.route('/users', methods=['POST', 'GET'])
def data():
# POST a data to database
if request.method == 'POST':
body = request.json
firstName = body['firstName']
lastName = body['lastName']
emailId = body['emailId']
# db.users.insert_one({
db['users'].insert_one({
"firstName": firstName,
"lastName": lastName,
"emailId":emailId
})
return jsonify({
'status': 'Data is posted to MongoDB!',
'firstName': firstName,
'lastName': lastName,
'emailId':emailId
})
# GET all data from database
if request.method == 'GET':
allData = db['users'].find()
dataJson = []
for data in allData:
id = data['_id']
firstName = data['firstName']
lastName = data['lastName']
emailId = data['emailId']
dataDict = {
'id': str(id),
'firstName': firstName,
'lastName': lastName,
'emailId': emailId
}
dataJson.append(dataDict)
print(dataJson)
return jsonify(dataJson)

@app.route('/users/<string:id>', methods=['GET', 'DELETE', 'PUT'])
def onedata(id):

# GET a specific data by id
if request.method == 'GET':
data = db['users'].find_one({'_id': ObjectId(id)})
id = data['_id']
firstName = data['firstName']
lastName = data['lastName']
emailId = data['emailId']
dataDict = {
'id': str(id),
'firstName': firstName,
'lastName': lastName,
'emailId':emailId
}
print(dataDict)
return jsonify(dataDict)
# DELETE a data
if request.method == 'DELETE':
db['users'].delete_many({'_id': ObjectId(id)})
print('\n # Deletion successful # \n')
return jsonify({'status': 'Data id: ' + id + ' is deleted!'})

# UPDATE a data by id
if request.method == 'PUT':
body = request.json
firstName = body['firstName']
lastName = body['lastName']
emailId = body['emailId']

db['users'].update_one(
{'_id': ObjectId(id)},
{
"$set": {
"firstName":firstName,
"lastName":lastName,
"emailId": emailId
}
}
)

print('\n # Update successful # \n')
return jsonify({'status': 'Data id: ' + id + ' is updated!'})

if __name__ == '__main__':
app.debug = True
app.run()

Run the server file using the following command. Make sure your MongoDB server is still running : 
$ python3 app.py
Your application server will run locally at http://localhost:5000




PART 2 - UI development using React.js

Now we are going to develop a React.js web application.

Package structure - Front end:




package.json

A package.json is a JSON file that subsists at the root of a Javascript/Node project. It holds metadata pertinent to the project and is utilized for managing the project's dependencies, scripts, version, and a whole lot more.
{
"name": "react-frontend",
"version": "0.1.0",
"private": true,
"dependencies": {
"@testing-library/jest-dom": "^4.2.4",
"@testing-library/react": "^9.5.0",
"@testing-library/user-
event": "^7.2.1",
"axios": "^0.19.2",
"bootstrap": "^4.5.0",
"react": "^16.13.1",
"react-dom": "^16.13.1",
"react-router-dom": "^5.2.0",
"react-scripts": "3.4.1"
},
"scripts": {
"start": "react-scripts start",
"build": "react-scripts build",
"test": "react-scripts test",
"eject": "react-scripts eject"
},
"eslintConfig": {
"extends": "react-app"
},
"browserslist": {
"production": [
">0.2%",
"not dead",
"not op_mini all"
],
"development": [
"last 1 chrome version",
"last 1 firefox version",
"last 1 safari version"
]
}
}



CreateUserComponent.json

import React, { Component } from 'react'

import UserService from '../services/UserService';
class CreateUserComponent extends Component {
constructor(props) {
super(props)
this.state = {
// step 2
id: this.props.match.params.id,
firstName: '',
lastName: '',
emailId: ''
}
this.changeFirstNameHandler = this.changeFirstNameHandler.bind(this);
this.changeLastNameHandler = this.changeLastNameHandler.bind(this);
this.saveOrUpdateUser = this.saveOrUpdateUser.bind(this);
}
// step 3
componentDidMount() {
// step 4
if (this.state.id === '_add') {
return
} else {
UserService.getUserById(this.state.id).then((res) => {
let user = res.data;
this.setState({
firstName: user.firstName,
lastName: user.lastName,
emailId: user.emailId
});
});
}
}
saveOrUpdateUser = (e) => {
e.preventDefault();
let user = { firstName: this.state.firstName,
lastName: this.state.lastName, emailId: this.state.emailId };
console.log('user => ' + JSON.stringify(user));
// step 5
if (this.state.id === '_add') {
UserService.createUser(user).then(res => {
this.props.history.push('/users');
});
} else {
UserService.updateUser(user, this.state.id).then(res => {
this.props.history.push('/users');
});
}
}
changeFirstNameHandler = (event) => {
this.setState({ firstName: event.target.value });
}
changeLastNameHandler = (event) => {
this.setState({ lastName: event.target.value });
}
changeEmailHandler = (event) => {
this.setState({ emailId: event.target.value });
}
cancel() {
this.props.history.push('/users');
}
getTitle() {
if (this.state.id === '_add') {
return <h3 className="text-center">Add User</h3>
} else {
return <h3 className="text-center">Update User</h3>
}
}
render() {
return (
<div>
<br></br>
<div className="container">
<div className="row">
<div className="card col-md-6 offset-md-3 offset-md-3">
{
this.getTitle()
}
<div className="card-body">
<form>
<div className="form-group">
<label> First Name: </label>
<input placeholder="First Name" name="firstName" className="form-control"
value={this.state.firstName} onChange={this.changeFirstNameHandler} />
</div>
<div className="form-group">
<label> Last Name: </label>
<input placeholder="Last Name" name="lastName" className="form-control"
value={this.state.lastName} onChange={this.changeLastNameHandler} />
</div>
<div className="form-group">
<label> Email Id: </label>
<input placeholder="Email Address" name="emailId" className="form-control"
value={this.state.emailId} onChange={this.changeEmailHandler} />
</div>
<button className="btn btn-success" onClick={this.saveOrUpdateUser}>
Save</button>
<button className="btn btn-danger" onClick={this.cancel.bind(this)}
style={{ marginLeft: "10px" }}>Cancel</button>
</form>
</div>
</div>
</div>
</div>
</div>
)
}
}
export default CreateUserComponent




ListUserComponent.jsx

import React, { Component } from 'react'

import UserService from '../services/UserService'
class ListUserComponent extends Component {
constructor(props) {
super(props)
this.state = {
users: []
}
this.addUser = this.addUser.bind(this);
this.editUser = this.editUser.bind(this);
this.deleteUser = this.deleteUser.bind(this);
}
deleteUser(id) {
UserService.deleteUser(id).then(res => {
this.setState({ users: this.state.users.
filter(user => user.id !== id) });
});
}
viewUser(id) {
this.props.history.push(`/view-user/${id}`);
}
editUser(id) {
this.props.history.push(`/add-user/${id}`);
}
componentDidMount() {
UserService.getUsers().then((res) => {
this.setState({ users: res.data });
});
}
addUser() {
this.props.history.push('/add-user/_add');
}
render() {
return (
<div>
<h2 className="text-center">Users List</h2>
<div className="row">
<button className="btn btn-primary" onClick={this.addUser}>
Add User</button>
</div>
<br></br>
<div className="row">
<table className="table table-striped table-bordered">
<thead>
<tr>
<th> User First Name</th>
<th> User Last Name</th>
<th> User Email Id</th>
<th> Actions</th>
</tr>
</thead>
<tbody>
{
this.state.users.map(
user =>
<tr key={user.id}>
<td> {user.firstName} </td>
<td> {user.lastName}</td>
<td> {user.emailId}</td>
<td>
<button onClick={() => this.editUser(user.id)} className="btn btn-info">
Update </button>
<button style={{ marginLeft: "10px" }} onClick={() => this.
deleteUser(user.id)} className="btn btn-danger">Delete </button>
<button style={{ marginLeft: "10px" }} onClick={() => this.
viewUser(user.id)} className="btn btn-info">View </button>
</td>
</tr>
)
}
</tbody>
</table>
</div>
</div>
)
}
}
export default ListUserComponent




UpdateUserComponent.jsx

import React, { Component } from 'react'

import UserService from '../services/UserService';
class UpdateUserComponent extends Component {
constructor(props) {
super(props)
this.state = {
id: this.props.match.params.id,
firstName: '',
lastName: '',
emailId: ''
}
this.changeFirstNameHandler = this.changeFirstNameHandler.bind(this);
this.changeLastNameHandler = this.changeLastNameHandler.bind(this);
this.updateUser = this.updateUser.bind(this);
}
componentDidMount() {
UserService.getUserById(this.state.id).then((res) => {
let user = res.data;
this.setState({
firstName: user.firstName,
lastName: user.lastName,
emailId: user.emailId
});
});
}
updateUser = (e) => {
e.preventDefault();
let user = { firstName: this.state.firstName,
lastName: this.state.lastName, emailId: this.state.emailId };
console.log('user => ' + JSON.stringify(user));
console.log('id => ' + JSON.stringify(this.state.id));
UserService.updateUser(user, this.state.id).then(res => {
this.props.history.push('/users');
});
}
changeFirstNameHandler = (event) => {
this.setState({ firstName: event.target.value });
}
changeLastNameHandler = (event) => {
this.setState({ lastName: event.target.value });
}
changeEmailHandler = (event) => {
this.setState({ emailId: event.target.value });
}
cancel() {
this.props.history.push('/users');
}
render() {
return (
<div>
<br></br>
<div className="container">
<div className="row">
<div className="card col-md-6 offset-md-3 offset-md-3">
<h3 className="text-center">Update User</h3>
<div className="card-body">
<form>
<div className="form-group">
<label> First Name: </label>
<input placeholder="First Name" name="firstName" className="form-control"
value={this.state.firstName} onChange={this.changeFirstNameHandler} />
</div>
<div className="form-group">
<label> Last Name: </label>
<input placeholder="Last Name" name="lastName" className="form-control"
value={this.state.lastName} onChange={this.changeLastNameHandler} />
</div>
<div className="form-group">
<label> Email Id: </label>
<input placeholder="Email Address" name="emailId" className="form-control"
value={this.state.emailId} onChange={this.changeEmailHandler} />
</div>
<button className="btn btn-success" onClick={this.updateUser}>Save</button>
<button className="btn btn-danger" onClick={this.cancel.bind(this)}
style={{ marginLeft: "10px" }}>Cancel</button>
</form>
</div>
</div>
</div>
</div>
</div>
)
}
}
export default UpdateUserComponent




ViewUserComponent.jsx
import React, { Component } from 'react'
import UserService from '../services/UserService'
class ViewUserComponent extends Component {
constructor(props) {
super(props)
this.state = {
id: this.props.match.params.id,
user: {}
}
}
componentDidMount() {
UserService.getUserById(this.state.id).then(res => {
this.setState({ user: res.data });
})
}
render() {
return (
<div>
<br></br>
<div className="card col-md-6 offset-md-3">
<h3 className="text-center"> View User Details</h3>
<div className="card-body">
<div className="row">
<label> User First Name: </label>
<div> {this.state.user.firstName}</div>
</div>
<div className="row">
<label> User Last Name: </label>
<div> {this.state.user.lastName}</div>
</div>
<div className="row">
<label> User Email ID: </label>
<div> {this.state.user.emailId}</div>
</div>
</div>
</div>
</div>
)
}
}
export default ViewUserComponent



UserService.js
import axios from 'axios';

const USER_API_BASE_URL = "http://localhost:5000/users";

class UserService {

getUsers(){
return axios.get(USER_API_BASE_URL);
}

createUser(user){
return axios.post(USER_API_BASE_URL, user);
}

getUserById(userId){
return axios.get(USER_API_BASE_URL + '/' + userId);
}

updateUser(user, userId){
return axios.put(USER_API_BASE_URL + '/' + userId, user);
}

deleteUser(userId){
return axios.delete(USER_API_BASE_URL + '/' + userId);
}
}

export default new UserService()



App.js
import React from 'react';
import logo from './logo.svg';
import './App.css';
import {BrowserRouter as Router, Route, Switch} from 'react-router-dom'
import ListUserComponent from './components/ListUserComponent';
import HeaderComponent from './components/HeaderComponent';
import FooterComponent from './components/FooterComponent';
import CreateUserComponent from './components/CreateUserComponent';
import UpdateUserComponent from './components/UpdateUserComponent';
import ViewUserComponent from './components/ViewUserComponent';

function App() {
return (
<div>
<Router>
<HeaderComponent />
<div className="container">
<Switch>
<Route path = "/" exact component = {ListUserComponent}></Route>
<Route path = "/users" component = {ListUserComponent}></Route>
<Route path = "/add-user/:id" component = {CreateUserComponent}></Route>
<Route path = "/view-user/:id" component = {ViewUserComponent}></Route>
</Switch>
</div>
<FooterComponent />
</Router>
</div>
);
}
export default App;



Run


npm install & npm start


Your application will run locally at http://localhost:3000



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