Book Image

Learn Chart.js

By : Helder da Rocha
Book Image

Learn Chart.js

By: Helder da Rocha

Overview of this book

Chart.js is a free, open-source data visualization library, maintained by an active community of developers in GitHub, where it rates as the second most popular data visualization library. If you want to quickly create responsive Web-based data visualizations for the Web, Chart.js is a great choice. This book guides the reader through dozens of practical examples, complete with code you can run and modify as you wish. It is a practical hands-on introduction to Chart.js. If you have basic knowledge of HTML, CSS and JavaScript you can learn to create beautiful interactive Web Canvas-based visualizations for your data using Chart.js. This book will help you set up Chart.js in a Web page and show how to create each one of the eight Chart.js chart types. You will also learn how to configure most properties that override Chart’s default styles and behaviors. Practical applications of Chart.js are exemplified using real data files obtained from public data portals. You will learn how to load, parse, filter and select the data you wish to display from those files. You will also learn how to create visualizations that reveal patterns in the data. This book is based on Chart.js version 2.7.3 and ES2015 JavaScript. By the end of the book, you will be able to create beautiful, efficient and interactive data visualizations for the Web using Chart.js.
Table of Contents (14 chapters)
Title Page
Copyright and Credits
About Packt


Patterns are a great way to create charts that don't depend on color-coding, and they can be used in color or monochromatic devices or print media. And they are, of course, color-blind safe. You can create patterns using HTML Canvas commands somewhat similar to the ones used for gradients, but it's much easier to use a plugin, such as the Patternomaly plugin, listed in the Chart.js official documentation.

You can obtain Patternomaly by downloading the JavaScript library from its GitHub repository ( or by using a CDN link:

<script src="[email protected]/dist/patternomaly.min.js">

To generate a pattern, all you have to do is choose a color and call pattern.generate(), which will randomly select 1 of the 21 patterns available:


You can also choose a specific pattern as the first argument of pattern.draw():

pattern.draw('triangle', 'lightblue');

A list of the supported...