Module: NSWTopo::ArcGIS::Query

Defined in:
lib/nswtopo/gis/arcgis/layer/query.rb

Constant Summary collapse

UniqueFieldError = 
Class.new RuntimeError

Instance Method Summary collapse

Instance Method Details

#base_query(**options) ⇒ Object 



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# File 'lib/nswtopo/gis/arcgis/layer/query.rb', line 6

def base_query(**options)
  case
  when @unique
    raise UniqueFieldError
  when @geometry
    raise "polgyon geometry required" unless @geometry.polygon?
    options[:geometry] = { rings: @geometry.reproject_to(projection).coordinates.map(&:reverse) }.to_json
    options[:geometryType] = "esriGeometryPolygon"
    options[:where] = join_clauses(*@where) if @where
  when @where
    options[:where] = join_clauses(*@where)
  else
    oid_field = @layer["fields"].find do |field|
      field["type"] == "esriFieldTypeOID"
    end&.fetch("name")
    options[:where] = oid_field ? "#{oid_field} IS NOT NULL" : "1=1"
  end
  options
end

#count ⇒ Object 



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# File 'lib/nswtopo/gis/arcgis/layer/query.rb', line 26

def count
  @count ||= get_json("#{@id}/query", **base_query, returnCountOnly: true).dig("count")
end

#pages(per_page) ⇒ Object 



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# File 'lib/nswtopo/gis/arcgis/layer/query.rb', line 30

def pages(per_page)
  objectids = get_json("#{@id}/query", **base_query, returnIdsOnly: true)["objectIds"] || []
  @count = objectids.count
  return [GeoJSON::Collection.new(projection: projection, name: @name)].each if @count.zero?

  @fields ||= @layer["fields"].select do |field|
    Layer::FIELD_TYPES === field["type"]
  end.map do |field|
    field["name"]
  end

  Enumerator.new do |yielder|
    out_fields = [*@fields, *extra_field].join ?,
    while objectids.any?
      begin
        get_json "#{@id}/query", outFields: out_fields, objectIds: objectids.take(per_page).join(?,)
      rescue Connection::Error
        (per_page /= 2) > 0 ? retry : raise
      end.fetch("features", []).filter_map do |feature|
        next unless geometry = feature["geometry"]
        properties = feature.fetch("attributes", {})

        case @geometry_type
        when "esriGeometryPoint"
          point = geometry.values_at "x", "y"
          next unless point.all?
          next GeoJSON::Point[point, properties]
        when "esriGeometryMultipoint"
          points = geometry["points"]
          next unless points&.any?
          next GeoJSON::MultiPoint[points.transpose.take(2).transpose, properties]
        when "esriGeometryPolyline"
          raise "ArcGIS curve geometries not supported" if geometry.key? "curvePaths"
          paths = geometry["paths"]
          next unless paths&.any?
          next GeoJSON::LineString[paths[0], properties] if @mixed && paths.one?
          next GeoJSON::MultiLineString[paths, properties]
        when "esriGeometryPolygon"
          raise "ArcGIS curve geometries not supported" if geometry.key? "curveRings"
          rings = geometry["rings"]
          next unless rings&.any?
          polys = GeoJSON::MultiLineString[rings.map(&:reverse), properties].to_multipolygon
          next @mixed && polys.one? ? polys.first : polys
        else
          raise "unsupported ArcGIS geometry type: #{@geometry_type}"
        end
      end.tap do |features|
        yielder << GeoJSON::Collection.new(projection: projection, features: features, name: @name)
      end
      objectids.shift per_page
    end
  end
end