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

Drawing with text


I agree, we've been working on some complicated things. Now, its time for us to lay back, kick off the shoes, and do something a bit easier.

Getting ready

The good news is, if you are on this page, you should already know the basics of getting a canvas up and running. So there isn't much more that you need to do besides picking the font, size, and position of your text.

Note

Here, we aren't covering how you can embed fonts that aren't created within JavaScript, but instead, via CSS, we will use a basic font and hope for the best in this sample.

How to do it...

In this example, we are going to create a text field. In this process, we are going to use gradients and shadows for the first time. Perform the following steps:

  1. Gain access to the canvas 2D API:

    var canvas = document.getElementById("textCanvas");
      var wid = canvas.width;
      var hei = canvas.height;
    
      var context = canvas.getContext("2d");
  2. Create a gradient style and fill the background with it:

    var grd = context.createLinearGradient...