Hacking Google Maps and Google Earth (ExtremeTech)

I Need to Get To...

O

ne of the most common roles that a map has to play is as a guide

from one place to another. Think about the last time you used a

map. Were you trying to find the location of something or to plan

a route from one location to another? Perhaps you were planning a walking

trip, a city tour, or just a way to avoid the latest bout of highway mainte-

nance on your route to work. These are simply examples. The point is that

people use maps to find and locate a route or distance between points.

This chapter examines an application that provides an interface for record-

ing, saving, and loading routes from a database. The user will be able to cre-

ate a new route, manually create the route’s sequence and point layout, and

save and name the route. The application can also obtain a list of the exist-

ing routes and their starting points and load an existing route. For an addi-

tional level of functionality, the application also allows the user to edit and

modify the route details, making a truly dynamic map route application.

The application is divided into two parts: the front end (the HTML and

the Google Maps interface) and the backend (the CGI script that provides

and stores information for the front-end application in a database). Each of

these parts is covered individually.

Front-End Interface

As usual, the front end of the application is a combination of some wrapper

HTML and the JavaScript that provides the interface to the Google Maps

API and provides the connectivity between the front-end application and

the backend CGI that provides the interface to the database that stores

information.

The application is large and is described here in individual sec-

tions according to the role or function that is being described.

The individual code fragments can be re-assembled into a final

application, or you can download the application from the book’s

web site (http://maps.mcslp.com).

̨Create a database

structure

̨Implement

JavaScript

̨Add and update

information

̨Calculate distance

̨Returning XML

chapter

in this chapter