Hacking Google Maps and Google Earth (ExtremeTech)

174 Part III — Google Map Hacks

Listing 9-20: Updating the onLoad() Function

function onLoad() {

if (GBrowserIsCompatible()) {

infopanel = document.getElementById(“infopanel”);

message = document.getElementById(“message”);

map = new GMap(document.getElementById(“map”));

map.centerAndZoom(new GPoint(-2.944336,53.644638), 10);

map.addControl(new GSmallZoomControl());

showcitylist();

}

}

That completes the JavaScript functionality. The next part of the application is the CGI script

that generates the XML used by this application.

Generating the XML on the Backend.

Listing 9-21 is an adaptation of the earlier XML generation scripts. Remember that the script

now needs to return two different pieces of information: a list of cities and a list of restaurants

within a given city. Both operations are triggered through certain CGI parameters specified by

the URL reference in the JavaScript component that wants to load the XML.

Listing 9-21: Generating the Necessary XML

#!/usr/bin/perl

use DBI;

use strict;

use CGI qw/:standard/;

print header(-type => ‘text/xml’);

my $dbh = DBI->connect( ‘dbi:mysql:database=mapsbookex;host=db.maps.mcslp.com’,

‘mapsbookex’,

‘examples’,

);

if (!defined($dbh))

{

die “Couldn’t open connection to database\n”;

}

if (param(‘m’) eq ‘citylist’)

{

citylist();