HTML and CSS Reference
In-Depth Information
CHAPTER 8
Geolocation
Christopher Deutsch and Marc Grabanski
8.0 Introduction
The W3C Geolocation API allows for scripted access to geographical location infor-
mation associated with a device's browser. In this chapter we'll first cover how to access
this API and then dive into some examples of what you can do with this data using
Google Maps and other third-party libraries like SimpleGeo.
All of the examples in this chapter use jQuery (see
http://jquery.com
)
, which can easily
be included using a
script
tag in one of two ways. There is no need to download the
jquery.js
file; your web page can use the version hosted on Google's Content Delivery
Network (CDN):
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.js"></script>
And, just in case a call to the file across the Internet isn't available, a fallback to a local
copy of the jQuery file can come right afterward in a second
script
element that checks
for the previous copy's successful inclusion:
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.js"></script>
<script>window.jQuery || document.write("<script
src='js/libs/jquery-1.6.4.min.js'>\x3C/script>")</script>
8.1 Getting Basic Geolocation Data
Problem
You want to find the location of the user's Internet device.
Solution
Use the new HTML5 Geolocation API to get the user's location when she clicks a button
and output the values to the web page, as shown in
Figure 8-1
.
