Book Image

Google Maps JavaScript API Cookbook

Book Image

Google Maps JavaScript API Cookbook

Overview of this book

Day by day, the use of location data is becoming more and more popular, and Google is one of the main game changers in this area. The Google Maps JavaScript API is one of the most functional and robust mapping APIs used among Geo developers. With Google Maps, you can build location-based apps, maps for mobile apps, visualize geospatial data, and customize your own maps.Google Maps JavaScript API Cookbook is a practical, hands-on guide that provides you with a number of clear, step-by-step recipes that will help you to unleash the capabilities of the Google Maps JavaScript API in conjunction with open source or commercial GIS servers and services through a number of practical examples of real world scenarios. This book begins by covering the essentials of including simple maps for Web and mobile, adding vector and raster layers, styling your own base maps, creating your own controls and responding to events, and including your own events.You will learn how to integrate open source or commercial GIS servers and services including ArcGIS Server, GeoServer, CartoDB, Fusion Tables, and Google Maps Engine with the Google Maps JavaScript API. You will also extend the Google Maps JavaScript API to push its capabilities to the limit with additional libraries and services including geometry, AdSense, geocoding, directions, and StreetView.This book covers everything you need to know about creating a web map or GIS applications using the Google Maps JavaScript API on multiple platforms.
Table of Contents (15 chapters)
Google Maps JavaScript API Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Getting elevations on a map with a click


The Google Maps JavaScript API provides information on elevation data, returning positive values on the terrain relative to the sea surface. It also gives information on the depth of ocean floors in negative values.

Using the ElevationService object, we can get elevation information on individual locations as well as paths.

In this recipe, firstly we will show how to get an elevation data from a single point that the user selects, and then we will go over the same scenario with the paths.

Getting ready

It is a good idea to have a quick glance at the Drawing shapes on the map recipe in Chapter 6, Google Maps JavaScript Libraries, as the recipe covers every detail on how to draw a shape using the Google Maps JavaScript API.

How to do it…

You can view the elevation data of a location of your choice if you follow the given steps:

  1. Define the elevator object as global:

    var elevator;
  2. Define the popup object as global:

    var popup;
  3. Initialize the elevator and popup objects...