Firebase: The google API for building Apps

Firebase is tool used for the backend and database of any app or website you might create. It’s a template for your app, that can be configured to your specific needs while delivering the basics. It’s made owned by google which makes it even more accessible. I use google for pretty much everything. Emails, writing, and countless other things. I actually didn’t know that something like Firebase existed a year ago. I mean who’s gonna give up a service like this for free-ish. Anyway lets get right into it.

Firebase offers Authentication

This is literally the bread and butter of any application. Users need to be identified and have a secure way of doing so. Firebase authentication consists of google auth, facebook auth, email only auth, github auth, email and password auth, and a few others. Users can safely change passwords, confirm their email, and even change the email they are using. Here’s the link to the docs for auth.

Firebase offers 2 different Databases and storage

Firebase is flexible, like really flexible. There are 2 different databases available: the real-time database, and the firestore. Both are great but personally I recommend the firestore. Storage is just for storing things that you cant keep in either database in your google cloud bucket.

1. Storage: https://firebase.google.com/docs/storage
2. Firestore: https://firebase.google.com/docs/firestore
3. Real-time Database: https://firebase.google.com/docs/database

Firebase offers cloud functions

Because of the nature of firebase you don’t have direct access to a server, but cloud functions solve that problem. You can export your functions to be called using triggers. So any server side code can be run no stress. Here’s the link to the docs
P.S you need to be on a paid plan to use Firebase cloud functions.

Now that all that’s been said here’s a quick example of how you might implement firebase into a react app.

import { useEffect, useState } from "react";
import firebase from "firebase/app";
import "firebase/auth";
import "firebase/firestore";


const config = {/*firebase project config*/};


try {
  firebase.initializeApp(config);
} catch (error) {
  !/already exists/.test(error.message) && console.error(error); 
}


function App() {
  const [show, setShow] = useState(false);
  const [messages, setMessages] = useState([]);
  useAuth(setShow);
  useFirestore(setMessages);
  return (
    <div>
      <h2>
        {
          show 
          ? "You're signed in yay!"
          : "You're not signed in. Please sign in."
        }
      </h2>
      {
        show
        ? <>
          <Messages addMessage={addMessage} messages={messages} />
          <br />
          <button onClick={logout}>Log Out</button>
        </>
        : <button onClick={login}>Log In</button>
      }
    </div>
  );
}


function Messages({ messages, addMessage }) {
  const [value, setValue] = useState("");
  return (
    <div>
      <p>
        {
          messages.map((message, index) => <span key={index}>{message}<br /></span>)
        }
      </p> 
      <br />
      <form onSubmit={(e) => {
        e.preventDefault();
        addMessage(value);
        setValue("");
      }}>
        <input value={value} onChange={(e) => setValue(e.target.value)} />
        <br />
        <button>Send</button>
      </form>
    </div>
  );
}


function useFirestore(setMessages) {
  const db = firebase.firestore();
  const auth = firebase.auth();
  return useEffect(() => {
    const unsubscribe = auth.currentUser && db.collection("userMessages").doc(auth.currentUser?.uid).onSnapshot((doc) => {
      doc.exists && setMessages([...doc.data().messages]);
    });
    return () => typeof(unsubscribe) === "function" && unsubscribe();
    //eslint-disable-next-line
  }, [auth.currentUser]);
}


async function login() {
    const provider = new firebase.auth.GoogleAuthProvider();
    const auth = firebase.auth();
    await auth.signInWithPopup(provider);
}


async function logout() {
  const auth = firebase.auth();
  await auth.signOut();
}


function useAuth(setShow) {
  const auth = firebase.auth();
  return useEffect(() => {
    auth.onAuthStateChanged((user) => {
      user?.uid ? setShow(true) : setShow(false);
    });
    //eslint-disable-next-line
  }, []);
}


async function addMessage(message) {
  const auth = firebase.auth();
  const db = firebase.firestore();
  await db.collection("userMessages").doc(auth.currentUser.uid).set({
    messages: firebase.firestore.FieldValue.arrayUnion(message)
  },{ 
    merge: true 
  });
};
          
export default App;