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

Time for action – creating a style function


We'll accomplish this in two steps. First, we'll replace the default style with a simple one, and then, we'll develop a new style to display smaller thumbnails:

  1. First, turn off automatic styling for the KML source by adding extractStyles: false to its options:

    var flickrSource = new ol.source.KML({
      url: '../assets/data/flickr_data.kml',
      projection: 'EPSG:3857',
      extractStyles: false
    });
  2. Now, create a new function that will generate styles for our photos, we'll use a simple circle style for now:

    function flickrStyle(feature) {
      var style = new ol.style.Style({
        image: new ol.style.Circle({
          radius: 6,
          stroke: new ol.style.Stroke({
            color: 'white',
            width: 2
          }),
          fill: new ol.style.Fill({
            color: 'green'
          })
        })
      });
      return [style];
    }
  3. That should do it, check out the result in the browser. This is what it looks like with the data saved in the assets folder, yours will look different if you...