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How to integrate Firebase and Firestore cloud database with a React application

Aman Mittal

June 20, 2019


Firebase is a Backend as a Service (BaaS) that gives an advantage to web developers who use ReactJS for developing web applications. It is a platform that got acquired by Google and has a healthy and active community. Most users in this community are web and mobile developers. It includes services like mobile analytics, push notification, crash reporting and out of the box provides email as well as social authentication. As a web developer, by using Firebase you can start building an MVP (minimum viable product) by keeping the costs low and utilizing your time and effort in building the application quite faster than adopting a traditional approach by building your own custom backend solution.

In this tutorial, we will be learning how to get started by integrating the Firebase and Firestore cloud database with a React application. We will also create a bare minimum demo application from scratch with the help of Firebase & React Native to see how they work together.

TLDR;

  • Requirements
  • Getting started: New Firebase Project
  • Connecting Firebase with React App
  • Creating a Firestore Database

Requirements

In order to gain everything by reading this tutorial, make sure you have:

  • a Firebase account (free tier)
  • NodeJS v8.x.x or higher installed along with npm/yarn
  • create-react-app global module to scaffold a React project

Getting Started: New Firebase Project

To get started you need a Firebase account. To sign-up or log-in for one, visit console.firebase.com. Once you are logged in, you will be welcomed by a screen below.

Click on the button Add Project. This leads to another screen which contains a form to be fulfilled in order to create a new Firebase project.

Fill the name of the project, check both the boxes for now and click on the button Create project. This will take some moments. Once the Firebase project is created, you will be welcomed by the home screen like below.

Take a look at the side menu bar on the left. This is the main navigation in any Firebase project. That's it for now. It is that simple to create a new Firebase project via the official console.

Create React App

To create a new react app, first, we need to install create-react-app by running the below command in a terminal window.

npm install -g create-react-app
# Check for the current version
create-react-app --version
# Output: 3.0.0

The second execution is to check the semantic version of create-react-app module. Make sure you are on the same version (which is latest at the time of writing this post) or higher than this.

To generate a new project run create-react-app react-firebase-demo. This will take some time to generate a new project and install dependencies that required to kick-start the default React app. Do note that, React by default uses yarn instead of npm as the JavaScript package manager to install dependencies.

Connecting Firebase with React App

To connect Firebase with a React app, you need API key and store in the client side app somewhere (probably as environmental variables when deploying the app). Click on the settings ⚙️ in the sidebar menu and go to Project settings. There you will see under Your apps section all the platforms available such as iOS, and web. Click on the Web as shown below.

Next, copy only the config variable in a new file called firebase.js inside the src directory of the React project. Initially, the file might look like below snippet.

//firebase.js
const config = {
apiKey: 'XXXX',
authDomain: 'XXXX',
databaseURL: 'XXXX',
projectId: 'XXXX',
storageBucket: 'XXXX',
messagingSenderId: 'XXXX'
}
firebase.initializeApp(config)

Where all the XXXXs are the key values. In order to continue, React app needs FirebaseSDK installed as an npm dependency. Open terminal window, make sure you are traversed inside the project directory and execute the following command.

yarn add firebase

Once the dependency is installed go back to firebase.js file and import firebase like below and it to the top of the file.

//firebase.js
import firebase from 'firebase/app'
// ...
export default firebase

You could have imported firebase from just firebase. The reason in the above file we are using firebase/app is that /app only adds the core of the firebase services. Right now, to integrate Firebase with our React app, we only need initializeApp() method to pass all the keys required to configure from the firebase.

While importing, if you use just firebase, it will include the whole bunch of services like auth, database, storage, functions, messaging, firestore, and so on. Most of them, we might not even need this demo application. This also increases the size of your bundle when deploying the application. Lastly, do not forget to export the instance configured firebase object that you will be using in the React app later.

Creating a Firestore Database

There are two types of cloud-based database services provided by Firebase. One is called Cloud Firestore and the other one is a Real-time Database. This does not mean that Cloud Firestore cannot be used for real-time applications. Also, note that both of them are NoSQL databases.

Real-time database stores data as one large JSON tree. Complex and scalable data is hard to organize in it. Firestore follows proper NoSQL terminology when it comes to storing data. It stores data in documents and each document can have sub-collections thus making it suitable for scalable and complex data scenarios.

Also, Realtime database only offers offline support for the mobile development using iOS and Android whereas Firestore supports both mobile platforms as well as web clients too. To read more about their differences you can visit the official documentation here.

In the Database section, choose the cloud Firestore and go to the second tab called Rules. If you are enabling Firestore for the first time, chances are you need to set the database security rules to test mode. This is where the firebase SDK will allow anyone (one who has access to the config keys) to read and write to the database. That said, this section should look like below.

service cloud.firestore {
match /databases/{database}/documents {
match /{document=**} {
allow read, write;
}
}
}

Open firebase.js and import firestore instance.

// firebase.js
// ... after other imports
import 'firebase/firestore'
// ... before export default statement
export const firestore = firebase.firestore()

Also, exporting the firestore instance will let you use it to query the database.

Now, go back to the Firebase console and go to the Data tab under Firestore.

You will notice that there is currently no data inside the database. The Add Collection button represents the column that will contain the name of each collection that you might have in the database. Let us add some data using Firebase console interface such that we can query and display it in the next section. Click on the button Add Collection and enter the name of the collection as shown below.

Click Next and enter two fields. One for the title of the book and the other one for the author's name. By default, the ID for each document will be auto-generated if the above option Auto-id is selected or remained untouched. Note that both of these fields represent one document as a whole.

Notice that, we have not defined value for both the fields. Also, both the fields are of data type string. Of course, there are other data types available and supported by Firestore. At last, click on the Save button to save the first, though the empty, entry in the Firestore database.

Did you notice how the ID for the document is generated on its own in the above image?

Creating the UI form

In this section, let us wire the React app to have a simple form that can be further used to send data and store it in the cloud. Currently, the React app is bare-minimum or default that is generated by the scaffolding tool create-react-app. To run it in its current state, from the terminal window execute npm start. This will start the development server, and open a new browser window in your default browser at the URL: http://localhost:3000/. If you do not have any errors (which you won't) you will see the following screen.

The code that is being rendered in the above screen comes from the only component we have so far in our React app, inside App.js file. Open this file and then define the following state. Right now, the App component is a functional component.

// App.js
class App extends React.Component {
state = {
title: '',
author: ''
}
render() {
return (
<div className="App">
<header className="App-header">
<img src={logo} className="App-logo" alt="logo" />
<p>
Edit <code>src/App.js</code> and save to reload.
</p>
<a
className="App-link"
href="https://reactjs.org"
target="_blank"
rel="noopener noreferrer"
>
Learn React
</a>
</header>
</div>
)
}
}

Notice that, for the App component to have stated, we converted it to a class component. Next, inside the render function, add the following form that contains two input fields.

// App.js
render() {
const { title, author } = this.state
return (
<div className='App'>
<form onSubmit={this.addBook}>
<input
type='text'
placeholder='Title of the Book?'
name='title'
onChange={this.updateInput}
value={title}
/>
<br />
<input
type='text'
placeholder='Author of the Book?'
name='author'
onChange={this.updateInput}
value={author}
/>
<br />
<button type='submit'>Submit</button>
</form>
</div>
)
}

This creates a not so awesome looking form but does serve the purpose of learning about Firestore.

Both the input fields have a value attribute to specify which field is a target from the state object. Also, both the fields call a custom method updateInput to update the component's the state corresponding to the book's data from the input field. Let us right the business logic behind it before the render function in the above snippet.

// App.js
updateInput = event => {
this.setState({ [event.target.name]: event.target.value })
}

Add data to the Firestore

In this section, you are going to write the logic behind how to add data from the React form to the Firestore. In the previous section, did you notice that the form has submitted button and an onSubmit event that leads to the function addBook. Define this function just before the render() method as below.

// import this at the top of your file
import { firestore } from './firebase'
// App.js
addBook = event => {
event.preventDefault()
firestore.collection('books').add({
title: this.state.title,
author: this.state.author
})
this.setState({ title: '', author: '' })
}

In the above snippet, let us start by import an instance of the firestore from firebase.js that we previously defined. The addBook function takes an event as an argument. The first line inside the function stops the web page from refreshing after submitting the form. Refreshing a web page after clicking the submit button is the default behavior and we need to avoid.

Next, using the firestore.collection("books") points to the correct database collection where the data will be added on submitting the form. The collection name here is books. The .add() method submits the data from the updated to the firestore. Try adding one. Make sure npm start is running.

After adding filling up the form as above, click on the submit button. After you add a book's title and its author, both the input field is set to the empty string, which is the default state and is a necessary step to add more data. Now, go back to the firebase console, to the books' collection and you will notice, as shown below, a new object with a random but unique ID and corresponding data in it.

Conclusion

You have now successfully integrated and added data to the Firebase store. The method discussed in this tutorial to access Firestore is not the only way, but yet a simple one. For more information or to dive deep, take a look at the Firestore documentation here.

Originally published at Crowdbotics

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Aman Mittal

I'm Aman a Computer Science engineer working as an independent fullstack developer. I specialize in web & mobile platforms working with technologies such as Node.js, ReactJS, and React Native. I write tutorials for JavaScript Web and Mobile developers.

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