Book Image

OpenLayers Cookbook

Book Image

OpenLayers Cookbook

Overview of this book

Data visualization and analysis has become an important task for many companies. Understanding the basic concepts of GIS and knowing how to visualize data on a map is a required ability for many professionals today. OpenLayers is a JavaScript library to load, display, and render maps from multiple sources on web pages."OpenLayers Cookbook" teaches how to work with OpenLayers, one of the most important and complete open source JavaScript libraries.Through an extensive set of recipes, this book shows how to work with the main concepts required to build a GIS web applicationñ maps, raster and vector layers, styling, theming, and so on."OpenLayers Cookbook" includes problem solving and how-to recipes for the most common and important tasks. A wide range of topics are covered.The range of recipes includes: creating basic maps, working with raster and vector layers, understanding events and working with main controls, reading features from different data sources, styling features, and understanding the underlying architecture."OpenLayers Cookbook" describes solutions and optimizations to problems commonly found.
Table of Contents (15 chapters)
OpenLayers Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Introduction


Once we know how to work with vector layers, such as adding new features or modifying the existing ones, the question we can have in mind is: how to style them?

The visual representation of features, the style, is one of the most important concepts in GIS applications. It is not only important from the user's experience or designer's perspective but also as an information requirement, for example, to identify features that match certain rules.

The way we visualize features is not only important to make our application much more attractive, but also to improve the way we bring information to the user. For example, given a set of points that represent some temperatures, if we are interested on the hottest zones, we could represent them with different radius and color values. This way, a lesser radius and a color near to blue means a cold zone while a greater radius and a color near to red means a hot zone.

OpenLayers offers us a great degree of flexibility when styling features...