Cloud Functions for Firebase Sample Library

This repository contains a collection of samples showcasing some typical uses of Cloud Functions for Firebase.

What's Cloud Functions for Firebase?

Cloud Functions is a hosted, private, and scalable Node.js environment where you can run JavaScript code. Cloud Functions for Firebase integrates the Firebase platform by letting you write code that responds to events and invokes functionality exposed by other Firebase features.

Prerequisites

To learn how to get started with Cloud Functions for Firebase by having a look at our Getting Started Guide, trying the quickstart samples and looking at the documentation.

Samples Overview

This repository contains a few categories of samples:

Quickstarts are minimal examples for each types of triggers.
Development Environment Samples and Boilerplates illustrates how to get started with different, commonly used JavaScript development patterns such as Typescript, React SSR, ES2017 etc...
Image Processing shows a few ways where you can process and transform images using Cloud Functions such as generating thumbnails, converting images extracting metadata...
Firebase Realtime Database Data Consistency show how to implement automatic data consistency such as keeping a count of children, having a max amount of node childs, cleaning up old data etc... for your Realtime Database.
Other common usecases a set of other common usecases for Cloud Functions.

Quickstarts

Here is a set of minial samples for each Cloud Functions trigger types.

Quickstart: Uppercaser for Realtime Database or Cloud Firestore

This quickstart sample demonstrates using Cloud Functions triggered by Firebase Realtime Database or Cloud Firestore events. The function uppercase messages written to the datastore.

HTTPS trigger quickstart: Time Server

This quickstart sample demonstrates using Cloud Functions triggered by HTTPS requests. The function returns the current server time and allows for date time formatting.

Hosting triggered HTTPS function quickstart: Big Ben

This quickstart demonstrates using Cloud Functions with an HTTPS trigger that's triggered through a Firebase Hosting URL. The function will display a repeated number of "BONG" depending on the hour of the day.

Cloud Storage trigger quickstart: Thumbnail generator

This quickstart sample demonstrates using Cloud Functions triggered by Firebase Storage events. The function generates a thumbnail of uploaded images.

Auth trigger quickstart: Welcome Email

This quickstart sample demonstrates using Cloud Functions triggered by Firebase Auth events. The functions sends a Welcome email when user accounts are created (or when users signs-in using an Identity Provider for the first time) and sends a Goodbye email when user accounts are deleted.

PubSub trigger quickstart: Hello World

This quickstart sample demonstrates using Cloud Functions triggered by PubSub events. The functions log the PubSub payload in a Hello world message.

Crashlytics trigger quickstart: Crashlytics Email Notifier

This quickstart sample demonstrates using Cloud Functions triggered by Crashlytics. The functions send an email when there is a new issue in an important conversion flow.

Development Environment Samples and Boilerplates

The Firebase CLI generates sample code for Cloud Functions using JavaScript that is natively supported in NodeJS. Most developers use more modern JavaScript or TypeScript which requires additional tools.

Write Cloud Functions using TypeScript

This sample shows how you can write your Cloud Functions code using Typescript. This requires a buld step, included as an npm script, which transpiles the source code to a supported version of JavaScript. Uses an HTTPS request.

Write Cloud Functions using ES2017 code

This sample shows how you can write your Cloud Functions code using the ES2017 syntax. This requires to run a preparation step where your code is transpiled to a supported version of JavaScript. Uses a Firebase Realtime Database trigger.

Server-side generated pages w/ Handlebars templating and user sessions

This samples shows how to serve server-side generated HTML pages using the HandlebarsJs templating system and serve User specific content by always passing the Firebase ID token in a __session cookie.

Isomorphic React App

This sample demonstrates how to create an isomorphic React application with server-side data fetching. This sample uses Cloud Functions, Hosting, and the Realtime Database.

Image Processing

Here is a few sample that shows how you can process or analyze images using Cloud Functions.

Image Maker

This sample demonstrates how to create various customized images such as sparkline or sphere charts through Cloud Functions and Hosting and serve it to the client. Uses an HTTP trigger.

Convert images after upload

Demonstrates how to automatically convert images that are uploaded to Firebase Storage to JPEG using ImageMagick. Uses a Firebase Storage trigger.

Generate image thumbnails using ImageMagick

Demonstrates how to automatically generate a thumbnail for images that are uploaded to Firebase Storage using ImageMagick and generate a public download link for the images. Uses a Firebase Storage trigger.

Generate image thumbnails using Node.js Stream & Sharp

Demonstrates how to use Node.js Stream to read image from Cloud Storage, generate a thumbnail image using Sharp and upload it back to Cloud Storage. Uses a Firebase Storage trigger.

Moderate offensive images

Demonstrates how to automatically moderate offensive images that are uploaded to Firebase Storage by using the Google Cloud Vision API to detect offensive images and ImageMagick to blur these images. Uses a Firebase Storage trigger.

Extract image metadata

Demonstrates how to automatically extract image's metadata using ImageMagick for images that are uploaded to Firebase Storage. Uses a Firebase Storage trigger.

Firebase Realtime Database Data Consistency

These samples show how to implement automatic data consistency such as keeping a count of children, having a max amount of node childs, cleaning up old data etc...

LastModified Firebase Database tracking

Tracking when the Firebase Database (or a subset) was last modified. Uses a Realtime Database trigger.

Firebase Database child nodes count

Keeps track of the number of child nodes of a Firebase Database element allowing clients to filter or order results using the child count. This can be useful to keep tack of the number of "likes" or "followers" of a somethings shares through social media. Uses a Realtime Database trigger.

Limit number of child nodes

Make sure to keep the number of child nodes below a certain threshold. For instance this can be useful to limit the number of lines of logs or chat history below a given number. Uses a Realtime Database trigger.

Removing old items from a list

This sample shows how to remove child nodes older than 2 hours from a Firebase Database list. This can be useful for removing outdated items from a collection. Uses a Realtime Database trigger.

Other common usecases

Send FCM notifications

This sample demonstrates how to send a Firebase Cloud Messaging (FCM) notification from a Realtime Database triggered Function when users get new followers. The sample also features a Web UI to experience the FCM notification. Uses a Realtime Database trigger.

Google Assistant says ordinal of given number

This sample shows how to create an action for the Google Home/Assistant using the Actions SDK hosted on Cloud Functions. The sample action asks users to say a number and reads out the ordinal of that number. Uses an HTTP trigger.

Authenticated JSON API

This sample shows how to authenticate access to a JSON API to only allow access to data for a specific Firebase user. Uses an HTTP trigger.

Authorized HTTP endpoint

This samples shows how to restrict an HTTPS Function to only the Firebase users of your app. Only users who pass a valid Firebase ID token as a Bearer token in the Authorization header of the HTTP request or in a __session cookie are authorized to use the function. Checking the ID token is done with an ExpressJs middleware that also passes the decoded ID token in the Express request object. Uses an HTTP trigger.

Authorize with LinkedIn, Spotify, Instagram, LINE or Basic Auth

Demonstrates how to authorize with a 3rd party sign-in mechanism, create a Firebase custom auth token, update the user's profile and authorize Firebase. Uses an HTTP trigger.

Post GitHub commits to Slack channel

Demonstrates how to automatically post GitHub commits to a Slack channel using an HTTPS triggered Function.

Create and charge customers with Stripe or Paypal

Demonstrates hows to integrate Firebase Auth and the Realtime database with Stripe via the Stripe Node.js library and whows how to create HTTP endpoints to charge customers via Paypal.

Text moderation

How to moderate user input text for bad words. For example this can be used to moderate usernames, chat or forum messages. Uses a Realtime Database trigger.

Email confirmation

Sends email confirmation after users subscribed to a mailing list. Uses a Realtime Database trigger.

Automatic message translation

Integrates the Google Translate API to perform automatic text translation across any number of languages. Language codes can be stored in Firebase for on the fly changes. Uses a Realtime Database trigger.

Automatic URL shortener

Integrates the Bit.ly API to shorten URLs automatically as they are added to the database. Uses a Realtime Database trigger.

Full-text search via Algolia for Realtime Database or Cloud Firestore

Enable full-text search on Firebase Database data or Cloud Firestore documents by using an Algolia hosted search service. Uses a Realtime Database or Cloud Firestore trigger.

Contributing

We'd love that you contribute to the project. Before doing so please read our Contributor guide.

VladimirHumeniuk/functions-samples