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


You can select which events your chart will respond to by locally configuring the property, or globally using The default configuration includes an array with six event names:

events: ["mousemove", "mouseout", "click", "touchstart", "touchmove", "touchend"]

These are the events the browser will listen to when the cursor is within the canvas context. They control the behavior of clickable items such as legend labels and tooltips. If you are writing your own handlers, you may wish to turn off some events by redefining the property to include an array containing fewer events. For example, if you want to disable hovering and touch events in a chart, allowing only the click event, you can add the following to your options configuration:

options: {
   events: ['click']

Configuring animations

You should have noted that when you click the button, the lines don't move to their new positions immediately. The chart transitions smoothly, and it takes...