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Geo-Coder-Free-0.28
River stage zero No dependents
3 ++
/ Geo::Coder::Free::MaxMind

NAME

Geo::Coder::Free::MaxMind - Provides a geocoding functionality using the MaxMind and GeoNames databases

VERSION

Version 0.28

SYNOPSIS

    use Geo::Coder::Free::MaxMind;

    my $geocoder = Geo::Coder::Free::MaxMind->new();
    my $location = $geocoder->geocode(location => 'Ramsgate, Kent, UK');

DESCRIPTION

Geo::Coder::Free::MaxMind provides an interface to free databases.

Refer to the source URL for licencing information for these files: cities.csv is from https://www.maxmind.com/en/free-world-cities-database; admin1.db is from http://download.geonames.org/export/dump/admin1CodesASCII.txt; admin2.db is from http://download.geonames.org/export/dump/admin2Codes.txt;

See also http://download.geonames.org/export/dump/allCountries.zip

To significantly speed this up, gunzip cities.csv and run it through the db2sql script to create an SQLite file.

METHODS

new

    $geocoder = Geo::Coder::Free::MaxMind->new();

Takes one optional parameter, directory, which tells the library where to find the files admin1db, admin2.db and cities.[sql|csv.gz]. If that parameter isn't given, the module will attempt to find the databases, but that can't be guaranteed

geocode

    $location = $geocoder->geocode(location => $location);

    print 'Latitude: ', $location->lat(), "\n";
    print 'Longitude: ', $location->long(), "\n";

    # TODO:
    # @locations = $geocoder->geocode('Portland, USA');
    # diag 'There are Portlands in ', join (', ', map { $_->{'state'} } @locations);

    # This will return one place in New Brunwsick, not them all
    # TODO: Arguably it should get them all from the database (or at least say the first 100) and return the central location
    my @locations = $geocoder->geocode({ location => 'New Brunswick, Canada' });
    die if(scalar(@locations) != 1);

reverse_geocode

    $location = $geocoder->reverse_geocode(latlng => '37.778907,-122.39732');

Returns a string, or undef if it can't be found.

ua

Does nothing, here for compatibility with other geocoders

AUTHOR

Nigel Horne, <njh@bandsman.co.uk>

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

BUGS

Lots of lookups fail at the moment.

The MaxMind data only contains cities.

Can't parse and handle "London, England".

The database contains Canadian cities, but not provinces, so a search for "New Brunswick, Canada" won't work

The GeoNames admin databases are in this class, they should be in Geo::Coder::GeoNames.

The data at https://github.com/apache/commons-csv/blob/master/src/test/resources/org/apache/commons/csv/perf/worldcitiespop.txt.gz?raw=true are 7 years out of date, and are unconsistent with the Geonames database.

If you search for something like "Sheppy, Kent, England" in list context, it returns them all. That's a lot! It should limit to, say 10 results (that number should be tunable, and be a LIMIT in DB.pm), and as the correct spelling in Sheppey, arguably it should return nothing.

SEE ALSO

VWF, MaxMind and geonames.

LICENSE AND COPYRIGHT

Copyright 2017-2020 Nigel Horne.

The program code is released under the following licence: GPL for personal use on a single computer. All other users (including Commercial, Charity, Educational, Government) must apply in writing for a licence for use from Nigel Horne at `<njh at nigelhorne.com>`.

This product includes GeoLite2 data created by MaxMind, available from https://www.maxmind.com/en/home. (Note that this currently gives a 403 error - I need to find the latest URL).