Sha256: cb31be8fadae32320720eb69a5809be489fa6486e5523e754840e92c95f31817
Contents?: true
Size: 1.14 KB
Versions: 14
Compression:
Stored size: 1.14 KB
Contents
require 'ostruct'
require 'digest/md5'
module SpatialFeatures
module Importers
class Shapefile < Base
def cache_key
@cache_key ||= Digest::MD5.hexdigest(features.to_json)
end
private
def each_record(&block)
file = Download.open(@data, unzip: '.shp')
proj4 = proj4_from_file(file)
RGeo::Shapefile::Reader.open(file.path) do |records|
records.each do |record|
yield OpenStruct.new data_from_wkt(record.geometry.as_text, proj4).merge(:metadata => record.attributes) if record.geometry.present?
end
end
end
def proj4_from_file(file)
# Sanitize "'+proj=utm +zone=11 +datum=NAD83 +units=m +no_defs '\n"
`gdalsrsinfo "#{file.path}" -o proj4`[/'(.+)'/,1].presence || raise('Could not determine shapefile projection. Check that `gdalsrsinfo` is installed.')
end
def data_from_wkt(wkt, proj4)
ActiveRecord::Base.connection.select_one <<-SQL
SELECT ST_Transform(ST_GeomFromText('#{wkt}'), '#{proj4}', 4326) AS geog, GeometryType(ST_GeomFromText('#{wkt}')) AS feature_type
SQL
end
end
end
end
Version data entries
14 entries across 14 versions & 1 rubygems