Data-Driven Documents (D3), developed by Mike Bostock and the D3 community in 2011, is the successor to Bostock's earlier Protovis library. It allows pixel-perfect rendering of data by abstracting the calculation of things such as scales and axes into an easy-to-use Domain-Specific Language (DSL), and uses idioms that should be immediately familiar to anyone with experience of using the popular jQuery JavaScript library. Much like jQuery, in D3, you operate on elements by selecting and then manipulating them via a chain of modifier functions. Especially within the context of data visualization, this declarative approach makes using it easier and more enjoyable than a lot of other tools out there. The official website, https://d3js.org/, features many great examples that show off the power of D3, but understanding them is tricky to start with. After finishing with this book, you should be able to understand D3 well enough to figure out the examples, tweaking them to fit your needs. If you want to follow the development of D3 more closely, check out the source code hosted on GitHub at https://github.com/d3.
In this chapter, we'll lay the foundations of what you'll need to run all the examples in the book. I'll explain how you can start writing ECMAScript 2017 (ES2017)--the latest and most advanced version of JavaScript--and show you how to use Babel to transpile it to ES5, allowing your modern JavaScript to be run on any browser. We'll then cover the basics of using D3 v4 to render a basic chart.
