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
Contributors
Preface
Index

Hovering interactions


Tooltips respond to hover events. The next table lists properties of the hover object, which can be configured globally using Chart.defaults.global.hover or locally using options.hover:

Object

Value

Description

intersect

true or false

Same behavior as tooltip.intersect. Tooltips can respond to different intersect states when hovering.

mode

nearest, index, dataset, x, y. Deprecated values are label (same as index), and single (behaves like nearest when intersect: true).

Same behavior as tooltip.mode. Tooltips can respond to a different mode when hovering.

axis

x, y, xy

Selects parameters that are used to calculate the distance from the value point to the cursor during a hover event. The default is x. Horizontal bar charts override this to y so that mode:index can select different bars.

animationDuration

Number

The duration of the animation. This affects any hovering events, including tooltips.

Configuration options for the hover object

Both the hover and the tooltip objects support the...