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

Listening for non-OpenLayers events


When developing a web mapping application, the use of OpenLayers is only a piece among the set of tools that we need to use. Adding other components, such as buttons, images, lists, and so on, and interacting with them are other tasks that we must work on.

Interacting with a OpenLayers.Map instance or OpenLayers.Layer subclass is easy because they trigger specific events, but what if we want to listen for events on a button or any DOM element?

For this purpose, OpenLayers offers us the OpenLayers.Event class (do not get confused with the plural OpenLayers.Events class). This is a helper class, which, among other things, allows us to listen for events in non-OpenLayers elements in a browser-independent way.

Note

Unfortunately the way to register event listeners in JavaScript is not the same in all browsers. Also, Microsoft differs from W3C (the WWW Consortium) in the way to register listeners. You can find more information at http://www.quirksmode.org/js/events_advanced...