KmlContains

Parse a KML file and check if geographic points fall inside the polygons it defines. Supports multiple polygons and polygons with holes (inner boundaries).

Using NSW Local Government Areas from data.gov.au as an example — download the ESRI Shapefile (GDA94) and convert it to KML with GDAL:

ogr2ogr -f KML nsw-lga.kml nsw_lga.shp

Then in Ruby:

region = KmlContains.parse_kml(File.read('nsw-lga.kml'))

sydney = KmlContains::Point.new(151.21, -33.87)
region.contains_point?(sydney)             # => true
region.contains_point?(151.21, -33.87)     # also works

melbourne = KmlContains::Point.new(144.96, -37.81)
region.contains_point?(melbourne)          # => false

# find which polygon contains a point and access its ExtendedData
lga = region.find { |p| p.contains_point?(sydney) }
lga.extended_data['LGA_NAME']              # => "Council of the City of Sydney"

Points are (longitude, latitude). You can pass a KmlContains::Point, a longitude/latitude pair, or any object that responds to x and y.

• Nokogiri

Originally created as border_patrol at Square by Zach Brock and Matt Wilson.

Contributors: Scott Gonyea, Rob Olson, Omar Qazi, Denis Haskin, Tamir Duberstein, Erica Kwan.

MIT