Creating graphics with D3.js

D3.js (abbreviation for Data-Driven Documents) is a JavaScript library built by Mike Bostock and other members of the Stanford Visualization Group for DOM manipulation, data transformation, and graphic creation. It uses a jQuery-like, data-driven approach and leverages all the capabilities of modern browsers and underlying web standards (such as HTML, CSS, and SVG).

D3.js is open source and hosted on GitHub (https://github.com/mbostock/d3) under a slightly modified BSD 3-clause license; therefore, it can be used in open source and commercial products without being required to release any modifications. GitHub itself uses D3.js to visualize the contribution history of repositories.

Throughout this book, we will use the stable version 3.5.6, but most examples should also work with different minor versions.

Including D3.js

There are multiple ways to include D3.js to your project:

• Using the package manager called bower (recommended), fetch the library by running the bower install d3#3.5.6 command from the terminal. Then, link the minified CSS file from the bower_components/ directory in the head section of the web page: <link rel="stylesheet" href="bower_components/d3/d3.min.css">.
• Using a CDN, such as cdnjs (this requires an active Internet connection while developing), include the minified CSS file from the CDN in the head section of the web page: <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.6/d3.min.js">.
• Manually download the 3.5.6 release from GitHub (https://github.com/mbostock/d3/releases) and unzip it into the libs/ directory. Then, link the minified CSS file from the libs/ directory in the head section of the web page <link rel="stylesheet" href="libs/d3/d3.min.css">.

I strongly recommend using the package manager called bower to manage your frontend dependencies. However, in the examples of the book, we will link D3.js directly from cdnjs for simplicity reasons; therefore, all the examples in the source of the book require an active Internet connection.

Finding additional resources

The ultimate resource for D3.js is the WIKI page of the GitHub project, which can be found at https://github.com/mbostock/d3/wiki. Here, you will also find examples and a detailed description of the API.

Another great resource for examples is Mike Bostock's page at http://bl.ocks.org/mbostock and his blog at http://bost.ocks.org/mike/.

For more detailed information and examples, I recommend reading the Mastering D3.js book by Pablo Navarro Castillo.