Book Image

Mastering OpenLayers 3

By : Gábor Farkas
Book Image

Mastering OpenLayers 3

By: Gábor Farkas

Overview of this book

OpenLayers 3 allows you to create stunning web mapping and WebGIS applications. It uses modern, cutting edge browser technologies. It is written with Closure Library, enabling you to build browser-independent applications without painful debugging ceremonies, which even have some limited fallback options for older browsers. With this guide, you will be introduced to the world of advanced web mapping and WebGIS. First, you will be introduced to the advanced features and functionalities available in OpenLayers 3. Next, you will be taken through the key points of creating custom applications with OpenLayers 3. You will then learn how to create the web mapping application of yours (or your company's) dream with this open source, expense-free, yet very powerful library. We’ll also show you how to make amazing looking thematic maps and create great effects with canvas manipulation. By the end of this book, you will have a strong command of web mapping and will be well on your way to creating amazing applications using OpenLayers 3.
Table of Contents (17 chapters)
Mastering OpenLayers 3
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Building the toolbar


In the first example, called ch05_toolbar, we create the constructor function for our management system and add some methods to it to add and remove controls. We don't need any styling at this point. Firstly, we create the constructor:

var toolBar = function (options) {
    'use strict';
    if (!(this instanceof toolBar)) {
        throw new Error('toolBar must be constructed with the new keyword.');
    } else if (typeof options === 'object' && options.map && options.target && options.layertree) {
        if (!(options.map instanceof ol.Map)) {
            throw new Error('Please provide a valid OpenLayers 3 map object.');
        }
        this.map = options.map;
        this.toolbar = document.getElementById(options.target);
        this.layertree = options.layertree;
        this.controls = new ol.Collection();
    } else {
        throw new Error('Invalid parameter(s) provided.');
    }
};

Similar to the layer tree, we use the use strict paradigm...