Mapping Hacks

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Chapter 7, Names and Places

#80 Automatically Geocode U.S. Addresses

HACK

geocoder.us can be queried via the XML-RPC and REST-ful interfaces, which

are available to any reasonable programming language. The basic steps are:

1. Get an address from a web form, database, or file.

2. Format that address and create a web-service request.

3. Call the geocoder.

4. Do something interesting with the result.

Geocoding with XML-RPC

XML-RPC is a way of making a request of a remote system (a Remote Proce-

dure Call, or RPC) and receiving the results in XML. The XML response

from geocoder.us is easy to script in Perl by using the

XMLRPC::Lite module.

Most modern languages have a library that will parse XML-RPC and return

results in an easy-to-manage form:

#!/usr/bin/perl

use XMLRPC::Lite;

use Data::Dumper;

use strict;

use warnings;

my $where = shift @ARGV

or die "Usage: $0 \"111 Main St, Anytown, KS\"\n";

my $result = XMLRPC::Lite

-> proxy( 'http://rpc.geocoder.us/service/xmlrpc' )

-> geocode( $where )

-> result;

print Dumper $result;

Before running the code, you need to install the XMLRPC::Lite Perl module.

This can be done via CPAN from the shell by typing

sudo perl -MCPAN -e

"XMLRPC::Lite"

.

Running the Hack

Write the previous script to a file called simplest_xmlrpc.pl and run it like

this:

./simplest_xmlrpc.pl "1005 Gravenstein Highway North, Sebastopol, CA 95472"

It should show you the following data structure:

$VAR1 ...