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

Features and geometries


We've been using feature objects throughout the chapter so far without really talking about the Feature class itself. We also hinted at the Geometry class, but we haven't gone into any detail so far. This section will cover both classes in a bit more detail so that you can gain a bit more confidence working with them. Don't worry—it's easy, you've already been exposed to both classes.

Before we get into the Feature class, we should go over the Geometry class, as it's used to create the actual geometry objects that make up a feature object.

The Geometry class

Although it is perfectly valid to create features without geometries, they can't be represented on a map. Therefore, the Geometry class is, from the map's point of view, the foundation of the feature object. The Feature class uses the Geometry class to store geometry information about the feature.

However, what exactly is the Geometry class? In a nutshell, it stores geographic information in the form of one or more...