Module: Charta

Defined in:
lib/charta.rb,
lib/charta/gml.rb,
lib/charta/kml.rb,
lib/charta/point.rb,
lib/charta/polygon.rb,
lib/charta/version.rb,
lib/charta/geo_json.rb,
lib/charta/geometry.rb,
lib/charta/line_string.rb,
lib/charta/bounding_box.rb,
lib/charta/multi_polygon.rb,
lib/charta/geometry_collection.rb

Overview

Charta aims to supply easy geom/geog tools

Defined Under Namespace

Classes: BoundingBox, GML, GeoJSON, Geometry, GeometryCollection, KML, LineString, MultiPolygon, Point, Polygon

Constant Summary collapse

SRS = 
{
  WGS84: 4326,
  CRS84: 4326,
  RGF93: 2143
}.freeze
VERSION = 
'0.1.8'.freeze

Class Method Summary collapse

Class Method Details

.camelcase(text, first_letter = :upper) ⇒ Object 



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# File 'lib/charta.rb', line 182

def camelcase(text, first_letter = :upper)
  ret = text.split(/[_\-]+/).map { |word| word[0..0].upcase + word[1..-1].downcase }.join
  ret = text[0..0].downcase + text[1..-1] if first_letter == :lower
  ret
end

.empty_geometry(srid = :WGS84) ⇒ Object 



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# File 'lib/charta.rb', line 112

def empty_geometry(srid = :WGS84)
  GeometryCollection.empty(srid)
end

.find_srid(srname_or_srid) ⇒ Object

Check and returns the SRID matching with srname or SRID.



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# File 'lib/charta.rb', line 140

def find_srid(srname_or_srid)
  if srname_or_srid.to_s =~ /\Aurn:ogc:def:crs:.*\z/
    x = srname_or_srid.split(':').last.upcase.to_sym
    SRS[x] || x
  elsif srname_or_srid.to_s =~ /\AEPSG::?(\d{4,5})\z/
    srname_or_srid.split(':').last
  elsif srname_or_srid.to_s =~ /\A\d+\z/
    srname_or_srid.to_i
  else
    SRS[srname_or_srid] || srname_or_srid
  end
end

.find_system(_srname) ⇒ Object 



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# File 'lib/charta.rb', line 135

def find_system(_srname)
  nil
end

.find_system_by_srid(_srid) ⇒ Object 



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# File 'lib/charta.rb', line 127

def find_system_by_srid(_srid)
  nil
end

.find_system_by_urn(_urn) ⇒ Object 



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# File 'lib/charta.rb', line 131

def find_system_by_urn(_urn)
  nil
end

.from(format, data) ⇒ Object 



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# File 'lib/charta.rb', line 153

def from(format, data)
  unless respond_to?("from_#{format}")
    raise "Unknown format: #{format.inspect}"
  end
  send("from_#{format}", data)
end

.from_geojson(data, srid = nil) ⇒ Object 



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# File 'lib/charta.rb', line 168

def from_geojson(data, srid = nil)
  new_geometry(::Charta::GeoJSON.new(data, srid).to_ewkt)
end

.from_gml(data, srid = nil, flatten_collection = false) ⇒ Object 



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# File 'lib/charta.rb', line 160

def from_gml(data, srid = nil, flatten_collection = false)
  new_geometry(::Charta::GML.new(data, srid).to_ewkt, nil, nil, flatten_collection)
end

.from_kml(data, flatten_collection = false) ⇒ Object 



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# File 'lib/charta.rb', line 164

def from_kml(data, flatten_collection = false)
  new_geometry(::Charta::KML.new(data).to_ewkt, nil, nil, flatten_collection)
end

.generate_ewkt(feature) ⇒ Object 



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# File 'lib/charta.rb', line 116

def generate_ewkt(feature)
  generator = RGeo::WKRep::WKTGenerator.new(tag_format: :ewkt, emit_ewkt_srid: true)
  generator.generate(feature)
end

.make_line(points, options = {}) ⇒ Object 



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# File 'lib/charta.rb', line 104

def make_line(points, options = {})
  options[:srid] ||= new_geometry(points.first).srid if points.any?
  options[:srid] ||= 4326

  ewkt = "SRID=#{options[:srid]};LINESTRING(" + points.map { |wkt| p = new_geometry(wkt); "#{p.x} #{p.y}" }.join(', ') + ')'
  new_geometry(ewkt)
end

.new_feature(coordinates, srs = nil, format = nil, _flatten_collection = true, _options = {}) ⇒ Object 



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# File 'lib/charta.rb', line 28

def new_feature(coordinates, srs = nil, format = nil, _flatten_collection = true, _options = {})
  geom_ewkt = nil
  if coordinates.is_a?(RGeo::Feature::Instance)
    return Geometry.feature(coordinates)
  elsif coordinates.is_a?(::Charta::Geometry)
    return coordinates
  elsif coordinates.to_s =~ /\A[[:space:]]*\z/
    geom_ewkt = empty_geometry(srs).to_ewkt
  elsif coordinates.is_a?(Hash) || (coordinates.is_a?(String) && ::Charta::GeoJSON.valid?(coordinates)) # GeoJSON
    srid = srs ? find_srid(srs) : :WGS84
    geom_ewkt = ::Charta::GeoJSON.new(coordinates, srid).to_ewkt
  elsif coordinates.is_a?(String)
    geom_ewkt = if coordinates =~ /\A[A-F0-9]+\z/ # WKB
                  if srs && srid = find_srid(srs)
                    generate_ewkt RGeo::Geos.factory(srid: srid).parse_wkb(coordinates)
                  else
                    generate_ewkt Geometry.factory.parse_wkb(coordinates)
                  end
                elsif format == 'gml' && ::Charta::GML.valid?(coordinates)
                  # required format 'cause kml geometries return empty instead of failing
                  ::Charta::GML.new(coordinates, srid).to_ewkt
                elsif format == 'kml' && ::Charta::KML.valid?(coordinates)
                  ::Charta::KML.new(coordinates).to_ewkt
                elsif coordinates =~ /^SRID\=\d+\;/i
                  if feature = Geometry.feature(coordinates)
                    generate_ewkt feature
                  else
                    Charta::GeometryCollection.empty.feature
                  end
                else # WKT expected
                  if srs && srid = find_srid(srs)
                    begin
                      f = RGeo::Geos.factory(srid: srid).parse_wkt(coordinates)
                    rescue RGeo::Error::ParseError => e
                      raise "Invalid EWKT (#{e.message}): #{coordinates}"
                    end
                    generate_ewkt f
                  else
                    generate_ewkt Geometry.feature(coordinates)
                  end
                end
  else # Default for RGeo
    geom_ewkt = generate_ewkt coordinates
  end
  if geom_ewkt.to_s =~ /\A[[:space:]]*\z/
    raise ArgumentError, "Invalid data: coordinates=#{coordinates.inspect}, srid=#{srid.inspect}"
  end
  Geometry.feature(geom_ewkt)
end

.new_geometry(coordinates, srs = nil, format = nil, _flatten_collection = true, _options = {}) ⇒ Object 



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# File 'lib/charta.rb', line 78

def new_geometry(coordinates, srs = nil, format = nil, _flatten_collection = true, _options = {})
  return coordinates if coordinates.is_a?(::Charta::Geometry)
  feature = Charta.new_feature(coordinates, srs, format, _flatten_collection, _options)
  type = feature.geometry_type
  geom = case type
         when RGeo::Feature::Point then
           Point.new(feature)
         when RGeo::Feature::LineString then
           LineString.new(feature)
         when RGeo::Feature::Polygon then
           Polygon.new(feature)
         when RGeo::Feature::MultiPolygon then
           MultiPolygon.new(feature)
         when RGeo::Feature::GeometryCollection then
           GeometryCollection.new(feature)
         else
           Geometry.new(feature)
         end
  geom
end

.new_point(lat, lon, srid = 4326) ⇒ Object 



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# File 'lib/charta.rb', line 99

def new_point(lat, lon, srid = 4326)
  feature = Charta.new_feature("SRID=#{srid};POINT(#{lon} #{lat})")
  Point.new(feature)
end

.parse_ewkt(coordinates) ⇒ Object 



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# File 'lib/charta.rb', line 121

def parse_ewkt(coordinates)
  # parser = RGeo::WKRep::WKTParser.new(factory, support_ewkt: true)
  # factory.parse_wkt(coordinates)
  coordinates
end

.underscore(text) ⇒ Object

Utility methods



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# File 'lib/charta.rb', line 174

def underscore(text)
  text.gsub(/::/, '/')
      .gsub(/([A-Z]+)([A-Z][a-z])/, '\1_\2')
      .gsub(/([a-z\d])([A-Z])/, '\1_\2')
      .tr('-', '_')
      .downcase
end