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

Adding a navigation history control


Probably the most commonly used control in our mapping applications will be the Navigation control. OpenLayers.Control.Navigation control integrates (makes use of) some other controls, such as OpenLayers.Control.DragPan, OpenLayers.Control.ZoomBox, or a wheel handler, which allows us to pan and zoom the map.

While navigating, moving, or zooming, it can be interesting to store a history of the navigation actions made by the user, so he/she can go back or forward to previous places. Fortunately, we don't need to reinvent the wheel. OpenLayers offers us the OpenLayers.Control.NavigationHistory control.

This recipe shows how easy it is to add it to our applications and benefit from its features.

As you can see in the screenshot, we are going to add a button above the map that will enable or disable the Navigation component.

How to do it...

  1. Create an HTML file with the required OpenLayers dependencies. Add the code for the toggle button that will enable/disable...