Santa Tracker - Build with Gatsby, React Leaflet

The Christmas season is a magical time of year. We have Santa flying around spreading cheer and Elf roaming around New York during our yearly rewatch with family and friends.

Buddy the Elf waving
Buddy the Elf waving

To get in the spirit, we’re going to spin up a web app that includes a map that tracks Santa on it!

What are we going to build?

We’re going to work through building a mapping app that tracks Santa’s route and his current location.

To achieve this, we’re going to spin up a premade Gatsby starter that will give us a basic foundation for a map, utilize Google’s unofficial API to grab Santa’s route, and overlay his position and route on top of the map with Leaflet.

Woah, a mapping app?

Ay Caramba
Ay Caramba

Yup. If you haven’t played with maps before, don’t be discouraged! It’s not as bad as you probably think. If you’d rather start with mapping basics, you can read more about how mapping works first.

What do we need before we get started?

For this exercise, I’m going to assume you have node or yarn installed. For each example, I’ll use yarn, but use the tool of your choice.

You’ll also want to install Gatsby’s CLI globally which will allow us to use their Starter tools.

To set up Gatsby’s CLI, run the following command:

yarn global add gatsby-cli

After, you should be able to run gatsby -h to see the available commands, which means it’s successfully installed.

Running gatsby -h to verify install
Running gatsby -h to verify install

For more info about the Gatsby CLI, you can check out their documentation.

Getting started with our map foundation

Once our command line tools are set up, the first thing we’ll want to do is create a new Gatsby project using a Leaflet starter I put together. It provides us with a basic setup with Leaflet and React Leaflet.

Starting in your project directory, let’s install the project:

gatsby new [directory]

Make sure to replace [directory] with the location you want to set up your project.

Once you run that command, Gatsby will clone that project without any of the git references and install the packages required to start.

Installing Gatsby Starter Leaflet
Installing Gatsby Starter Leaflet

To make sure it works, you can now navigate to that directory, spin up your server, and test it in the browser:

cd [directory]
yarn develop

Where you see [directory] above, make sure to use the same path as you did before when setting up the new Gatsby project.

Running Gatsby Starter Leaflet
Running Gatsby Starter Leaflet

If all goes as planned, your server should start and you should now be able to see your basic mapping app in your browser!

Gatsby Starter Leaflet in the browser

Cleaning things up

This starter comes with a quick example of how we can interact with the map. We’re not going to need this at all for our purposes so we can go ahead and clean things up.

To start, we’re going to open up our index.js file, the homepage file, and get rid of everything inside of the mapEffect function, which leaves us with:

// In src/pages/index.js

async function mapEffect({ leafletElement } = {}) {
  // Get rid of everything in here

Now, let’s remove the Marker component nested inside of our Map, so we end up with:

<Map {…mapSettings} />

Now that we’re no longer using that functionality, we can get rid of the variables and references at the top of the file, so you can go ahead and remove:

  • useRef
  • promiseToFlyTo
  • getCurrentLocation
  • Marker
  • gatsby_astronaut
  • ZOOM
  • timeToZoom
  • timeToOpenPopupAfterZoom
  • timeToUpdatePopupAfterZoom
  • popupContentHello
  • popupContentGatsby
  • markerRef

Follow along with the commit.

Finding Santa

Now that we’re in a good place, let’s get our hands dirty and find Santa. To do this, we’re going to use Google’s unofficial, undocumented API. This means that it’s possible this API won’t be available the day after this get’s published, but let’s be optimistic.

Additionally, at the time of writing, it’s still showing last year’s destinations, so what we’re really going to be visualizing here is Santa’s previous year’s route, though the hope is this would reset on the 24th and we’ll all be merry!

Before we get Santa, let’s first add a line back to our mapEffect function:

async function mapEffect({ leafletElement } = {}) {
  if ( !leafletElement ) return;

What this will do is prevent the rest of our code from running in the event our map isn’t ready yet. The mapEffect function itself, as you can see in the Map component, runs inside of an instance of useEffect passing an argument of a ref to the map, allowing us to run some code after our component renders.

So once we have that line, let’s now fetch Santa’s route inside of our mapEffect function:

async function mapEffect({ leafletElement } = {}) {
  if ( !leafletElement ) return;
  let santa, santaJson, route, routeJson;
  try {
    santa = await fetch(‘’);
    santaJson = await santa.json();
    route = await fetch(santaJson.route);
    routeJson = await route.json();
  } catch(e) {
    throw new Error(`Failed to find Santa!: ${e}`)
  console.log(‘routeJson’, routeJson);

Let’s break this down:

  • We fetch Santa himself using our API endpoint
  • Once we have Santa, we grab the response in a JSON format to make it easier to work with
  • From that response, we grab Santa’s route URL
  • We fetch Santa’s route using that URL and again grab it in a JSON format
  • This is all wrapped in a try/catch so we can safely handle any response errors
  • Finally, we just log out our response for now

Santa's route object in the web console
Santa’s route object in the web console

Now we have Santa and his route, which means we can see all the destinations in his route. If you dig in the response a little bit, you can see some fun things like how many presents were delivered to each location and the weather at the time!

Follow along with the commit.

Put a pin in his location

We found Santa! Now let’s put him on the map.

For our purposes, we’ll need to find the latitude and longitude of Santa. The problem is, we don’t get this exact value defined anywhere, we just get his destinations.

Since we don’t have his location specified anywhere, we can utilize his last known location where presents were delivered. Add the following after our last snippet inside the mapEffect function:

const { destinations } = routeJson;
const destinationsWithPresents = destinations.filter(({presentsDelivered}) => presentsDelivered > 0);
const lastKnownDestination = destinationsWithPresents[destinationsWithPresents.length - 1]

Below our request code, we:

  • Destructure routeJson to grab destinations into a constant
  • Filter the results to find only the locations with presents
  • And finally grab the last item from the array, which shows his last known location

And as we can see, since we’re looking at last year’s data, Santa is back home at the North Pole.

Santa's last known location in the web console

With his location, we can pull that apart, set up a Leaflet marker instance, and add our old friend to the map. Add the following after our last snippet inside the mapEffect function:

const santaLocation = new L.LatLng(, lastKnownDestination.location.lng );

const santaMarker = L.marker( santaLocation, {
  icon: L.divIcon({
    className: ‘icon’,
    html: `<div class=“icon-santa”>🎅</div>`,
    iconSize: 50


Here we:

  • Create a Leaflet LatLng instance with his location
  • Create a Marker instance with our newly created LatLng instance
  • Add our new Marker to the map

If we refresh our page, you’ll have to zoom out and pan up a little bit, but we’ll see Santa on the map!

Santa on the map

Before we move on, let’s give Santa a little holiday cheer to make him easier to find. Find your application.scss file and toss these styles in:

// In src/assets/stylesheets/application.scss

.icon {

  & > div {

    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    border-radius: 100%;
    box-shadow: 0 3px 4px rgba(0,0,0,.4);
    border: none;
    transition: all .2s;

    &:hover {
      box-shadow: 0 4px 8px rgba(0,0,0,.6);



.icon-santa {
  width: 50px;
  height: 50px;
  font-size: 3em;
  background: white;

This just adds a white circle around him, a little drop shadow, and increases the size a bit to make him a little easier to find on the map.

Santa styled on the map

Follow along with the commit.

Drawing his route

The last thing we’re going to do here is draw a path on the map showing his route so we can follow along.

To get started, let’s update our code and add this last bit after our last snippet in the mapEffect function:

// Create a set of LatLng coordinates that make up Santa's route

const santasRouteLatLngs = => {
  const { location } = destination;
  const { lat, lng } = location;
  return new L.LatLng( lat, lng );

// Utilize Leaflet's Polyline to add the route to the map

const santasRoute = new L.Polyline( santasRouteLatLngs, {
  weight: 2,
  color: 'green',
  opacity: 1,
  fillColor: 'green',
  fillOpacity: 0.5

// Add Santa to the map!


What we’re doing:

  • Creating an array of Leaflet LatLng instances that make up Santa’s route
  • Creating a Leaflet Polyline (a multi-point line) using that routes array
  • Make that Polyline green
  • Add our Polyline to the map

What we get… is a bunch of squiggly lines!

Santa's route on the map

This is expected. This gets technical really fast, but Leaflet by default can only understand 1 “portion” of the map as it wraps around in our browser. What this realistically means, is instead of drawing a line around a globe, the coordinates think it goes from one side of the world to the other as it hits the International Dateline. This is a bit out of scope for this tutorial, but you can check out Leaflet.Antimeridian to learn more and see if you can implement the solution to it.

Follow along with the commit.

A few quick style tweaks

One last thing! And this is completely optional. Let’s make the map a little bit bigger, set the background color to match our oceans, and zoom out a little bit. So let’s make a few changes:

// In src/pages/index.js

const DEFAULT_ZOOM = 1;

We’re setting our default zoom to 1 instead of 2 to allow the map to be zoomed out a bit.

// In src/assets/stylesheets/pages/_home.scss

.page-home {

  .map-base {
    height: 80vh;


We’re setting our map to a height of 80vh instead of 50vh to make it take up a little more of our screen.

// In src/assets/stylesheets/components/_map.scss
.map {

  .map-base {
    background: #acd3de;


We’re setting the background color of our map to #acd3de instead of $blue-grey-50 which allows us to match the color of the oceans on our map.

What this achieves is being able to see Santa’s full route and Santa on the first view. Additionally, since the map only covers part of the screen, setting the background color of the map allows us to not have a little bit of a weird cutoff.

Santa's route zoomed out

Follow along with the commit.

Want a challenge?

To take this 1 step further, follow along with both how we added the routes and Santa to the map and try to see if you can add a marker to each destination location to show where all of the stops are. Bonus, add a popup to each one that says how many presents were delivered to that location!

To see the answer with some code organization and how I added the gift markers, check out the final version of the Santa Tracker demo.

Final Santa Tracker demo

While you’re there, you can also see how I utilized Leaflet.Antimeridian to fix our map’s route.

What did we learn?

Building basic apps with a map isn’t nearly as bad as we thought! We learned how to fetch some data from an API, grab the data we need, and draw representations of that data on a map.

Next time you want to add a map widget to your landing page, try Leaflet. Share what you create on Twitter! Would love to see what you come up with.

I hope you and your family have a fantastic holiday season!

Happy Holidays from Dunder Mifflin

#reactjs #javascript #programming

What is GEEK

Buddha Community

Santa Tracker - Build with Gatsby, React Leaflet
Autumn  Blick

Autumn Blick


How native is React Native? | React Native vs Native App Development

If you are undertaking a mobile app development for your start-up or enterprise, you are likely wondering whether to use React Native. As a popular development framework, React Native helps you to develop near-native mobile apps. However, you are probably also wondering how close you can get to a native app by using React Native. How native is React Native?

In the article, we discuss the similarities between native mobile development and development using React Native. We also touch upon where they differ and how to bridge the gaps. Read on.

A brief introduction to React Native

Let’s briefly set the context first. We will briefly touch upon what React Native is and how it differs from earlier hybrid frameworks.

React Native is a popular JavaScript framework that Facebook has created. You can use this open-source framework to code natively rendering Android and iOS mobile apps. You can use it to develop web apps too.

Facebook has developed React Native based on React, its JavaScript library. The first release of React Native came in March 2015. At the time of writing this article, the latest stable release of React Native is 0.62.0, and it was released in March 2020.

Although relatively new, React Native has acquired a high degree of popularity. The “Stack Overflow Developer Survey 2019” report identifies it as the 8th most loved framework. Facebook, Walmart, and Bloomberg are some of the top companies that use React Native.

The popularity of React Native comes from its advantages. Some of its advantages are as follows:

  • Performance: It delivers optimal performance.
  • Cross-platform development: You can develop both Android and iOS apps with it. The reuse of code expedites development and reduces costs.
  • UI design: React Native enables you to design simple and responsive UI for your mobile app.
  • 3rd party plugins: This framework supports 3rd party plugins.
  • Developer community: A vibrant community of developers support React Native.

Why React Native is fundamentally different from earlier hybrid frameworks

Are you wondering whether React Native is just another of those hybrid frameworks like Ionic or Cordova? It’s not! React Native is fundamentally different from these earlier hybrid frameworks.

React Native is very close to native. Consider the following aspects as described on the React Native website:

  • Access to many native platforms features: The primitives of React Native render to native platform UI. This means that your React Native app will use many native platform APIs as native apps would do.
  • Near-native user experience: React Native provides several native components, and these are platform agnostic.
  • The ease of accessing native APIs: React Native uses a declarative UI paradigm. This enables React Native to interact easily with native platform APIs since React Native wraps existing native code.

Due to these factors, React Native offers many more advantages compared to those earlier hybrid frameworks. We now review them.

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Aubrey  Price

Aubrey Price


Build a simple React Native Pokemon app with React-Navigation

As we start learning new technologies we want to start building something or work on a simple project to get a better understanding of the technology. So, let’s build this simple app.
For this app, we will be using PokeApi to get our pokemon data, and also we will be using Hooks. I am using pokemondb for pokemon sprites. It’s just a personal preference you can use whatever you want.

#react-native #react-native-app #react-navigation #react-native-development #react

Mathew Rini


How to Select and Hire the Best React JS and React Native Developers?

Since March 2020 reached 556 million monthly downloads have increased, It shows that React JS has been steadily growing. React.js also provides a desirable amount of pliancy and efficiency for developing innovative solutions with interactive user interfaces. It’s no surprise that an increasing number of businesses are adopting this technology. How do you select and recruit React.js developers who will propel your project forward? How much does a React developer make? We’ll bring you here all the details you need.

What is React.js?

Facebook built and maintains React.js, an open-source JavaScript library for designing development tools. React.js is used to create single-page applications (SPAs) that can be used in conjunction with React Native to develop native cross-platform apps.

React vs React Native

  • React Native is a platform that uses a collection of mobile-specific components provided by the React kit, while React.js is a JavaScript-based library.
  • React.js and React Native have similar syntax and workflows, but their implementation is quite different.
  • React Native is designed to create native mobile apps that are distinct from those created in Objective-C or Java. React, on the other hand, can be used to develop web apps, hybrid and mobile & desktop applications.
  • React Native, in essence, takes the same conceptual UI cornerstones as standard iOS and Android apps and assembles them using React.js syntax to create a rich mobile experience.

What is the Average React Developer Salary?

In the United States, the average React developer salary is $94,205 a year, or $30-$48 per hour, This is one of the highest among JavaScript developers. The starting salary for junior React.js developers is $60,510 per year, rising to $112,480 for senior roles.

* React.js Developer Salary by Country

  • United States- $120,000
  • Canada - $110,000
  • United Kingdom - $71,820
  • The Netherlands $49,095
  • Spain - $35,423.00
  • France - $44,284
  • Ukraine - $28,990
  • India - $9,843
  • Sweden - $55,173
  • Singapore - $43,801

In context of software developer wage rates, the United States continues to lead. In high-tech cities like San Francisco and New York, average React developer salaries will hit $98K and $114per year, overall.

However, the need for React.js and React Native developer is outpacing local labour markets. As a result, many businesses have difficulty locating and recruiting them locally.

It’s no surprise that for US and European companies looking for professional and budget engineers, offshore regions like India are becoming especially interesting. This area has a large number of app development companies, a good rate with quality, and a good pool of React.js front-end developers.

As per Linkedin, the country’s IT industry employs over a million React specialists. Furthermore, for the same or less money than hiring a React.js programmer locally, you may recruit someone with much expertise and a broader technical stack.

How to Hire React.js Developers?

  • Conduct thorough candidate research, including portfolios and areas of expertise.
  • Before you sit down with your interviewing panel, do some homework.
  • Examine the final outcome and hire the ideal candidate.

Why is React.js Popular?

React is a very strong framework. React.js makes use of a powerful synchronization method known as Virtual DOM, which compares the current page architecture to the expected page architecture and updates the appropriate components as long as the user input.

React is scalable. it utilises a single language, For server-client side, and mobile platform.

React is steady.React.js is completely adaptable, which means it seldom, if ever, updates the user interface. This enables legacy projects to be updated to the most new edition of React.js without having to change the codebase or make a few small changes.

React is adaptable. It can be conveniently paired with various state administrators (e.g., Redux, Flux, Alt or Reflux) and can be used to implement a number of architectural patterns.

Is there a market for React.js programmers?
The need for React.js developers is rising at an unparalleled rate. React.js is currently used by over one million websites around the world. React is used by Fortune 400+ businesses and popular companies such as Facebook, Twitter, Glassdoor and Cloudflare.

Final thoughts:

As you’ve seen, locating and Hire React js Developer and Hire React Native developer is a difficult challenge. You will have less challenges selecting the correct fit for your projects if you identify growing offshore locations (e.g. India) and take into consideration the details above.

If you want to make this process easier, You can visit our website for more, or else to write a email, we’ll help you to finding top rated React.js and React Native developers easier and with strives to create this operation

#hire-react-js-developer #hire-react-native-developer #react #react-native #react-js #hire-react-js-programmer

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Read More:-

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Aria Barnes

Aria Barnes


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The most awaited version of React 18 is finally out now. Its team has finally revealed the alpha version of React 18 and its plan, though the official launch is still pending. This time the team has tried something and released the plan first to know their user feedback because the last version of React 17 was not that much appreciated among developers.

According to Front-end Frameworks SurveyReact JS has ranked top in the list of most loved frameworks. Thus, the developer communities expect a bit higher from the framework, so they are less appreciative of the previous launch.
ReactJS stats.pngSo, this time React 18 will be a blast. For beginners, the team is working on a new approach. They have called a panel of experts, library authors, educators, and developers to take part in a working group. Initially, it will be a small group.

I am not a part of this release but following the team on their GitHub discussion group. After gathering the information from there, I can say that they have planned much better this time.

React 17 was not able to meet the developer's community. The focus was all primarily centered on making it easier to upgrade React itself. React 18 release will be the opposite. It has a lot of features for react developers.

Read more here: React 18: Things You Need To Know About React JS Latest Version

#hire react js developers #hire react js developers india #react developers india #react js developer #react developer #hire react developers