Book Image

HTML5 Graphing and Data Visualization Cookbook

By : Ben Fhala
Book Image

HTML5 Graphing and Data Visualization Cookbook

By: Ben Fhala

Overview of this book

The HTML5 canvas tag makes creating any plot shape easy, all you have to do then is fill it with exciting visualizations written in JavaScript or using other visualization tools. "HTML5 Graphing and Data Visualization Cookbook" is the perfect break into the world of Canvas, charts, and graphs in HTML5 and JavaScript. In this book we will go through a journey of getting to know the technology by creating and planning data-driven visualizations. This cookbook is organized in a linear, progressive way so it can be read from start to finish, as well as be used as a resource for specific tasks.This book travels through the steps involved in creating a fully interactive and animated visualization in HTML5 and JavaScript. You will start from very simple "hello world"ù samples and quickly dive deeper into the world of graphs and charts in HTML5. Followed by learning how canvas works and carrying out a group of tasks geared at taking what we learned and implementing it in a variety of chart types. With each chapter the content becomes more complex and our creations become more engaging and interactive.Our goal is that by the end of this book you will have a strong foundation; knowing when to create a chart on your own from scratch and when it would be a good idea to depend on other APIs.We finish our book in our last two chapters exploring Google maps and integrating everything we learnt into a full project.
Table of Contents (17 chapters)
HTML5 Graphing and Data Visualization Cookbook
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Stacking graphical layers


Before we can do any real animations on our canvas we really need to rethink the concept of building everything on one canvas layer. Once a canvas element is drawn, it's incredibly hard to create subtle small changes to it, such as fade-ins for specific elements. We will revisit one of our famous charts, the bar chart, which we played around with and enhanced many times throughout the earlier chapters. In this chapter, our goal will be to break the logic apart and make it more modular. In this recipe we will separate layers. Each layer will give us more control later when we are ready to animate.

Getting ready

Start by grabbing the latest files from the previous chapter: 05.02.line-revisit.html and 05.02.line-revisit.js.

How to do it...

The following changes are made to the HTML file:

  1. Update the HTML file to incorporate more canvas elements (one per drawn line):

    <body onLoad="init();" style="background:#fafafa">
        <h1>Users Changed between within a year...