Book Image

OpenLayers 3: Beginner's Guide

By : Thomas Gratier, Paul Spencer, Erik Hazzard
Book Image

OpenLayers 3: Beginner's Guide

By: Thomas Gratier, Paul Spencer, Erik Hazzard

Overview of this book

<p>This book is a practical, hands-on guide that provides you with all the information you need to get started with mapping using the OpenLayers 3 library.</p> <p>The book starts off by showing you how to create a simple map. Through the course of the book, we will review each component needed to make a map in OpenLayers 3, and you will end up with a full-fledged web map application. You will learn the key role of each OpenLayers 3 component in making a map, and important mapping principles such as projections and layers. You will create your own data files and connect to backend servers for mapping. A key part of this book will also be dedicated to building a mapping application for mobile devices and its specific components.</p>
Table of Contents (22 chapters)
OpenLayers 3 Beginner's Guide
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Time for action – setting up Proj4js.org


This step is similar to the way we set up the now usual template for OpenLayers 3.

  1. Download Proj4js from https://github.com/proj4js/proj4js/releases. At the time of writing, the latest version was proj4js 2.3.3; so, go ahead and download it by clicking on the proj4.js green button for 2.3.3 (or whichever the latest version is).

  2. Copy the proj4.js file into a new assets/proj4js directory at the root code directory.

  3. Add the following line in the <head> section of your code before the OpenLayers 3 library inclusion code:

    <script src="../assets/proj4js/proj4.js">
    </script>
  4. You can also use the online source, http://cdnjs.cloudflare.com/ajax/libs/proj4js/2.3.3/proj4.js, for production purposes. In this case, do not forget to use a fallback to the local file if the CDN fails for any reason.

  5. Now, open up the page and start Chrome Developer Tools. Type and run the following code:

    var test_proj = proj4('EPSG:4326');
    console.log(test_proj);
  6. You should...