Learn Flow, Leaflet and Serverless

Starting from a prebuilt frontend, Jason Lengstorf guides you through the creation of a "Corgi Up-boop App" that uses Netlify Functions and Hasura. You can view [the deployed final product on Netlify](https://egghead-serverless-functions.netlify.app/).

You'll set up the Netlify CLI, and configure a local development environment before writing and deploying functions with a few different use cases.

The first example function bypasses CORS restrictions to retrieve corgi data from an example third-party API.

Next, you'll configure environmental variables to securely communicate with the Unsplash API without exposing private keys to the client.

Serverless functions don't persist data by themselves, so we will use  Hasura to create a GraphQL API for tracking the number of "boops" each corgi receives.

This course is an excellent illustration of the speed of Serverless functions, and how fast you can implement functionality in your web applications.

An all-in-one workflow that combines global deployment, continuous integration, and automatic HTTPS.

netlify

Build a Corgi Up-boop Web App with Netlify Serverless Functions and Hasura

If you've ever worked on a website for a business, there's a good chance you've included a map.

A Google Map embed is sufficient for showing a location, but doesn't leave you many customization options.

React Leaflet to the rescue!

In this course, Colby Fayock will guide you through a series of lessons and challenges that will build your map making skills as you build out a web app for a fictional restaurant.

You'll get practice with handling API keys and using React Hooks to implement a custom interactive map complete with metadata and additional overlays.

This course has built-in challenges that you are encouraged to pause and work through, but feel free to just watch.

React is one of the web’s most popular frameworks for building JavaScript applications. 

If you know what you’re doing, React can drastically simplify how you build, use, and maintain code.

Whether you’re a React newbie or you’re ready for advanced techniques, you can level-up with egghead. Explore our in-depth courses, lessons, and community resources to build more powerful applications and crack open your career.

react

Build Maps with React Leaflet

In this collection, you'll learn the basics of creating a new map in your React application with React Leaflet. We'll walk through adding the map itself as well as adding markers with popups, different shapes, and increasingly complex features to your map!

Mapping with React Leaflet

Create a serverless application and deploy it in under thirty minutes!

We'll be using Netlify, Vite, TypeScript, and React in our project. This stack synergizes extremely well for rapidly developing professional-quality applications. 

If you haven't heard of Vite, it's the French word for quick! It's also a build tool that consists of a dev-server and an extremely fast bundler. It makes for a rapid development loop.

As for the rest. Netlify makes hosting fast and easy with serverless functions and continuous deployment. React enables you to quickly create reusable components. And TypeScript helps you write cleaner code that is easier to refactor. 

So get started and learn how to use this stack in your own applications!

Create a TypeScript powered serverless React application

flow

We'll go over some of the built-in types in Flow and how to add them to our projects by adding type annotations to our variables in JavaScript. We'll also learn about type mismatch errors when we give a variable a value that doesn't match its type annotation and how to fix it.

Primitive Types in Flow

Leaflet is the leading open-source JavaScript library for mobile-friendly interactive maps. Weighing just about 38 KB of JS, it has all the mapping features most developers ever need.

leaflet

Leaflet makes creating maps in the browser *dead simple*. With some HTML and 3 lines of JavaScript, we can quickly have a map displaying.

Get Started with LeafletJS Mapping

With a basic map in place we can add shapes, like US states. We will then see how to style the shapes to make a visually appealing map.

Adding Shapes to Maps with Leaflet and GeoJSON

Let's learn how to set up Facebook's Flow inside of a project and write a simple typecheck task that will let us run Flow against any files in our codebase.

Up and Running with Facebook Flow for Typed JavaScript

Nuclide is the IDE Facebook employees use to write React code. But setting it up to use Flow type checking and Eslint to lint files on the fly is tricky. This video shows you how. 

Setup Nuclide to use Flow and Eslint (Mac)

Rendering GeoJSON data on a map and interacting via mouse over, mouse out, and click.

Interactive Leaflet Maps with GeoJSON data

In this lesson we are going to add types throughout our basic todo list component. This includes type checking the component props, local state, and property methods. 

Type Check React Components With Flow

In this lesson we are going to take a React and Redux application and add flow types throughout. This includes type checking a react component, a reducer, some actions, and a connect method. 

Type Check Redux Apps with Flow

In this lesson, you will learn how to add a map to your React application using React Leaflet. We will walk through importing and configuring the Map and TileLayer components from React Leaflet to set up the new map.

Create a New Map using React Leaflet

In this lesson, you will learn how to add a Marker and Popup component to a Map when using React Leaflet. We'll walk you through importing the components and adding each one to the Map. Additionally, we'll resolve an issue with loading marker images that's inherent to creating a new React Leaflet map in Create React App, which we'll fix by manually importing the image from Leaflet and configuring those images to the marker.

Add a React Leaflet Marker with a Popup to a Map

In this lesson, you will learn how to add the Polygon and Circle shape components to a Map when using React Leaflet. We'll walk you through importing both components, adding each component to the Map, and setting a unique color for each shape.

Add Shapes to a Map in React Leaflet

In this lesson, you'll learn how to style shapes on your map to change the look and feel using React Leaflet's API. We'll use React component props like color and weight on our shapes to change the colors and styles.

Style React Leaflet Shapes using Component Props

In this lesson, you'll learn how to use CSS to style and animate shapes on your React Leaflet map. We'll use the className prop to add a custom class and add CSS to customize our shapes.

Style and Animate a React Leaflet Shape with Custom CSS

In this lesson, you will learn how to use React hooks to interface with the Leaflet Map API in React Leaflet. We'll connect a ref to our Map component using the useRef hook and then use the useEffect hook to access that ref, find our Map instance, and use it to fly to a new location.

[More details on the Leaflet Map API](https://leafletjs.com/reference-1.6.0.html#map)

Interface with the React Leaflet Map API with the useRef and useEffect React Hooks

In this lesson, we'll use an image to create a custom map marker icon for GeoJSON location data on our map. We'll walk through importing a custom image, creating a new Leaflet Icon and Marker instance, and use them to customize our National Parks markers.

Customize GeoJSON Data Markers with a React Leaflet Icon Image

In this lesson, you learn how to use the React Leaflet ZoomControl component to add a custom zoom control to your map. We'll walk through removing the default control to avoid duplicates, using the ZoomControl position prop to change its location, and setting custom icons with the zoomInText and zoomOutText props.

Change the React Leaflet Map ZoomControl Location and Icons

In this lesson, you will learn how to add GeoJSON data to a map in React Leaflet. Using the National Parks in the United States, we'll import a GeoJSON document, create a new Leaflet GeoJSON instance, and add a marker with a popup for each park.

[Parks Locations Example](https://www.nps.gov/maps/tools/npmap.js/examples/geojson-layer/)
[Parks GeoJSON](https://www.nps.gov/lib/npmap.js/4.0.0/examples/data/national-parks.geojson)