# ReactFire Quickstart ⚛ + 🔥 = 🌯 We'll build a web app that displays, in _real time_, the tastiness of a burrito. It will listen to **Cloud Firestore** for its data, and we'll configure **Firebase Performance Monitoring** so we can get some perf stats. To see the completed app, check out [this StackBlitz workspace](https://stackblitz.com/fork/reactfire-sample). ## 1. In a terminal, create a fresh React app and `cd` into its directory > Prerequisite: make sure you have [Node.js](https://nodejs.org/en/) installed. ```shell npx create-react-app myapp cd myapp ``` ## 2. Install ReactFire and the Firebase SDK ```bash # yarn yarn add firebase reactfire # npm npm install --save firebase reactfire ``` ## 3. Create a document in Cloud Firestore 1. Go to the _Database_ tab in the Firebase console. If your project doesn't have a Cloud Firestore instance yet, initialize it in locked mode 1. Add a document 1. In the _Data_ tab of the console, click _Add Collection_ 1. Name the collection **_tryreactfire_** 1. Add a document with ID **_burrito_** and boolean field `yummy: true` ![new document screenshot](https://firebasestorage.googleapis.com/v0/b/rxfire-525a3.appspot.com/o/docs%2FScreen%20Shot%202019-07-03%20at%202.19.11%20PM.png?alt=media&token=052d27ea-5db1-4a02-aad0-a3f017c1a975) 1. Add the following to your security rules and click _Publish_ ```text match /tryreactfire/burrito { allow read: if true; allow write: if request.auth.uid != null; } ``` ## 4. Modify `src/index.js` 1. Import Firebase and ReactFire ```js //... import { FirebaseAppProvider } from 'reactfire'; //... ``` 1. Wrap your app in a `FirebaseAppProvider` and provide the config object from the Firebase console ```jsx //... const firebaseConfig = { /* add your config object from Firebase console */ }; ReactDOM.createRoot(document.getElementById('root')).render( ); //... ``` ## 5. Modify `src/App.js` 1. Import the `useFirestoreDocData` and `useFirestore` hooks ```js //... import { useFirestoreDocData, useFirestore } from 'reactfire'; //... ``` 1. Add a function component ```jsx //... function Burrito() { // lazy load the Firestore SDK and create a document reference const burritoRef = useFirestore() .collection('tryreactfire') .doc('burrito'); // subscribe to the doc. just one line! const burrito = useFirestoreDocData(burritoRef); // get the value from the doc const isYummy = burrito.yummy; return

The burrito is {isYummy ? 'good' : 'bad'}

; } //... ``` 1. Render your component inside of a `Suspense` tag > We need to do this because `useFirestoreDocData` throws a Promise while it is waiting for a response from Firestore. Suspense will catch the Promise and render `fallback` until the Promise is resolved. Replace the `App` function with the following: ```jsx //... function App() { return (
{/* SuspenseWithPerf behaves the same as Suspense, but also automatically measures load times with the User Timing API and reports it to Firebase Performance Monitoring */}
); } //... ``` ## 6. Run your app! ```bash yarn start # or npm run start ``` 1. Edit the value of `yummy` in the Firebase console, and watch it update in real time in your app! 🔥🔥🔥 ## _About Firebase Performance Monitoring_ `SuspenseWithPerf` will lazy load the Firebase Performance Monitoring library and report on on our custom trace, `load-burrito-status`, that we set in the `traceId` prop of `SuspenseWithPerf`. In addition, it will automatically measure [common performance stats](https://firebase.google.com/docs/perf-mon/automatic-web)! Note that Firebase Performance Monitoring can take about 12 hours to crunch your data and show it in the _Performance_ tab of the Firebase console. This is an example of some of the stats in the Firebase Performance Monitoring console after 12 hours: ![Performance screenshot](https://firebasestorage.googleapis.com/v0/b/rxfire-525a3.appspot.com/o/docs%2FScreen%20Shot%202019-07-03%20at%202.43.29%20PM.png?alt=media&token=079547b5-ba5d-46bc-acfa-d9dedc184dc5)