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

Using point features as markers


Displaying markers is not only limited to using the OpenLayers.Marker and OpenLayers.Layer.Markers classes.

A marker can be understood as a point of interest (POI) where we place an icon to identify it and has some information associated with it: a monument, a parking area, a bridge, and so on.

In this recipe, we will learn how to use these features with a point geometry type associated to create markers.

How to do it...

  1. Once you have created the right HTML file with OpenLayers dependencies, add a div element to hold the map:

    <div id="ch3_feature_markers" style="width: 100%; height: 100%;"></div>
  2. Start initializing the map instance and add a base layer and control:

        // Create the map using the specified DOM element
        var map = new OpenLayers.Map("ch3_feature_markers");    
        
        var layer = new OpenLayers.Layer.OSM("OpenStreetMap");
        map.addLayer(layer);
        
        map.addControl(new OpenLayers.Control.LayerSwitcher());
        map.setCenter(new...