Introduction
Many projects on the web need to interface with a REST API at some stage in their development. Axios is a lightweight HTTP client based on the $http service within Angular.js v1.x and is similar to the native JavaScript Fetch API.
Axios is promise-based, which gives you the ability to take advantage of JavaScript’s async and await for more readable asynchronous code.
You can also intercept and cancel requests, and there’s built-in client-side protection against cross-site request forgery.
In this article, you will see examples of how to use Axios to access the popular JSON Placeholder API within a React application.
Prerequisites
To follow along with this article, you’ll need the following:
Node.js version 10.16.0 installed on your computer. To install this on macOS or Ubuntu 18.04, follow the steps in How to Install Node.js and Create a Local Development Environment on macOS or the Installing Using a PPA section of How To Install Node.js on Ubuntu 18.04.
A new React project set up with Create React App by following the How to Set up a React Project with Create React App tutorial.
It will also help to have a basic understanding of JavaScript, which you can find in the How To Code in JavaScript series, along with a basic knowledge of HTML and CSS.
This tutorial was verified with Node.js v16.13.1, npm v8.1.4, react v17.0.2, and axios v0.24.0.
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Step 1 — Adding Axios to the Project
In this section, you will add Axios to a React project you created following the How to Set up a React Project with Create React App tutorial.
npx create-react-app react-axios-example
To add Axios to the project, open your terminal and change directories into your project:
cd react-axios-example
Then run this command to install Axios:
npm install axios@0.24.0
Next, you will need to import Axios into the file you want to use it in.
Step 2 — Making a GET Request
In this example, you create a new component and import Axios into it to send a GET request.
Inside your React project, you will need to create a new component named PersonList.
First, create a new components subdirectory in the src directory:
mkdir src/components
In this directory, create PersonList.js and add the following code to the component:
src/components/PersonList.js
import React from 'react';
import axios from 'axios';
export default class PersonList extends React.Component {
state = {
persons: []
}
componentDidMount() {
axios.get(`https://jsonplaceholder.typicode.com/users`)
.then(res => {
const persons = res.data;
this.setState({ persons });
})
}
render() {
return (
<ul>
{
this.state.persons
.map(person =>
<li key={person.id}>{person.name}</li>
)
}
</ul>
)
}
}
First, you import React and Axios so that both can be used in the component. Then you hook into the componentDidMount lifecycle hook and perform a GET request.
You use axios.get(url) with a URL from an API endpoint to get a promise which returns a response object. Inside the response object, there is data that is then assigned the value of person.
You can also get other information about the request, such as the status code under res.status or more information inside of res.request.
Add this component to your app.js:
src/app.js
import PersonList from './components/PersonList.js';
function App() {
return (
<div ClassName="App">
<PersonList/>
</div>
)
}
Then run your application:
npm start
View the application in the browser. You will be presented with a list of 10 names.
Step 3 — Making a POST Request
In this step, you will use Axios with another HTTP request method called POST.
Inside your React project, you will need to create a new component named PersonAdd.
Create PersonAdd.js and add the following code to create a form that allows for user input and subsequently POSTs the content to an API:
src/components/PersonAdd.js
import React from 'react';
import axios from 'axios';
export default class PersonAdd extends React.Component {
state = {
name: ''
}
handleChange = event => {
this.setState({ name: event.target.value });
}
handleSubmit = event => {
event.preventDefault();
const user = {
name: this.state.name
};
axios.post(`https://jsonplaceholder.typicode.com/users`, { user })
.then(res => {
console.log(res);
console.log(res.data);
})
}
render() {
return (
<div>
<form onSubmit={this.handleSubmit}>
<label>
Person Name:
<input type="text" name="name" onChange={this.handleChange} />
</label>
<button type="submit">Add</button>
</form>
</div>
)
}
}
Inside the handleSubmit function, you prevent the default action of the form. Then update the state to the user input.
Using POST gives you the same response object with information that you can use inside of a then call.
To complete the POST request, you first capture the user input. Then you add the input along with the POST request, which will give you a response. You can then console.log the response, which should show the user input in the form.
Add this component to your app.js:
src/app.js
import PersonList from './components/PersonList';
import PersonAdd from './components/PersonAdd';
function App() {
return (
<div ClassName="App">
<PersonAdd/>
<PersonList/>
</div>
)
}
Then run your application:
npm start
View the application in the browser. You will be presented with a form for submitting new users. Check the console after submitting a new user.
Step 4 — Making a DELETE Request
In this example, you will see how to delete items from an API using axios.delete and passing a URL as a parameter.
Inside your React project, you will need to create a new component named PersonRemove.
Create PersonRemove.js and add the following code to delete a user:
src/PersonRemove.js
import React from 'react';
import axios from 'axios';
export default class PersonRemove extends React.Component {
state = {
id: ''
}
handleChange = event => {
this.setState({ id: event.target.value });
}
handleSubmit = event => {
event.preventDefault();
axios.delete(`https://jsonplaceholder.typicode.com/users/${this.state.id}`)
.then(res => {
console.log(res);
console.log(res.data);
})
}
render() {
return (
<div>
<form onSubmit={this.handleSubmit}>
<label>
Person ID:
<input type="number" name="id" onChange={this.handleChange} />
</label>
<button type="submit">Delete</button>
</form>
</div>
)
}
}
Again, the res object provides you with information about the request. You can then console.log that information again after the form is submitted.
Add this component to your app.js:
src/app.js
import PersonList from './components/PersonList';
import PersonAdd from './components/PersonAdd';
import PersonRemove from './components/PersonRemove';
function App() {
return (
<div ClassName="App">
<PersonAdd/>
<PersonList/>
<PersonRemove/>
</div>
)
}
Then run your application:
npm start
View the application in the browser. You will be presented with a form for removing users.
Step 5 — Using a Base Instance in Axios
In this example, you will see how you can set up a base instance in which you can define a URL and any other configuration elements.
Create a separate file named api.js:
nano src/api.js
Export a new axios instance with these defaults:
src/api.js
import axios from 'axios';
export default axios.create({
baseURL: `http://jsonplaceholder.typicode.com/`
});
Once the default instance is set up, it can then be used inside of the PersonRemove component. You import the new instance like this:
src/components/PersonRemove.js
import React from 'react';
import API from '../api';
export default class PersonRemove extends React.Component {
// ...
handleSubmit = event => {
event.preventDefault();
API.delete(`users/${this.state.id}`)
.then(res => {
console.log(res);
console.log(res.data);
})
}
// ...
}
Because http://jsonplaceholder.typicode.com/ is now the base URL, you no longer need to type out the whole URL each time you want to hit a different endpoint on the API.
Step 6 — Using async and await
In this example, you will see how you can use async and await to work with promises.
The await keyword resolves the promise and returns the value. The value can then be assigned to a variable.
src/components/PersonRemove.js
import React from 'react';
import API from '../api';
export default class PersonRemove extends React.Component {
// ...
handleSubmit = event => {
event.preventDefault();
const response = await API.delete(`users/${this.state.id}`);
console.log(response);
console.log(response.data);
}
// ...
}
In this code sample, the .then() is replaced. The promise is resolved, and the value is stored inside the response variable.
Conclusion
In this tutorial, you explored several examples on how to use Axios inside a React application to create HTTP requests and handle responses.
If you’d like to learn more about React, check out the How To Code in React.js series, or check out the React topic page for more exercises and programming projects.
