Reactive Programming with RxJS

Making a Real-Time Earthquake Visualizer

Using the concepts that we’ve covered so far in this chapter, we’ll build a web application that uses RxJS to show us where earthquakes are happening in real time. We’ll start by building a functional but naive reactive implementation, and we’ll improve it as we go. The final result will look like this:

Preparing Our Environment

We’ll use the USGS (U.S. Geological Survey) earthquake database,^[12] which offers a real-time earthquake dataset in several formats. We will get our data from the weekly dataset in JSONP format.

We’ll also use Leaflet, a JavaScript library, to render interactive maps.^[13] Let’s ...