This is a geocoder C++ library that targets offline use by mobile applications. It is able to perform forward and reverse geocoding. For forward geocoding, it uses libpostal to parse the user request, normalize the parsed result, and search for the match in geocoder database. In addition to traditional reverse geocoding, it is able to find points of interest close to the reference point or line.
The library includes demo program showing how to use it. Its also used as one of the geocoders in OSM Scout Server (https://github.com/rinigus/osmscout-server). For preparation of the SQLite database used by the geocoder, an importer from liboscmscout map database is provided.
When using country-based libpostal address parser and limiting number of languages used to process the search request, it is possible to use this geocoder on mobile platforms. The development of the geocoder is mainly targeting Sailfish OS applications with the tests running on Linux as well. Its expected that the geocoder would run on platforms supported by libpostal without any major changes.
To compile, adjust Makefile. The library can be used by incorporating
source code files in src subdirectory and ensuring that
thirdparty/sqlite3pp/headeronly_src is in the compiler's include
path.
In addition to libpostal, libsqlite3 is required for the geocoder to function. For importer, libosmscout is required in addition to the libraries mentioned above.
At present, the datasets required for the geocoder to function are distributed as a part of OSM Scout Server datasets.
If you use the geocoder with the full libpostal installation, you don't need to get the libpostal datasets from that location, but can use the datasets provided by libpostal. This is a default when there is no path specified for corresponding libpostal datasets.
To use country-specific datasets, you would have to get:
- libpostal language parser: postal/global
- libpostal country-specific database: postal/countries/SELECT THE NEEDED ONES
In addition, the prepared geocoder databases are available at geocoder/SELECT THE NEEDED ONES.
Database format is described in separate document.
libpostal: Used for input parsing; https://github.com/openvenues/libpostal
Nominatim: Used for data import; https://nominatim.org/