Contents

module RCAP
	# A Polygon object is valid if
	# * it has a minimum of three points
	# * each Point object in the points collection is valid
	class Polygon
    include Validation

		# Collection of Point objects.
    attr_reader( :points )

    validates_length_of( :points, :minimum => 3 )
    validates_collection_of( :points )

    XML_ELEMENT_NAME = 'polygon'                   # :nodoc: 
    XPATH            = "cap:#{ XML_ELEMENT_NAME }" # :nodoc: 

    def initialize( attributes = {})
      @points = Array( attributes[ :points ])
    end

    def to_s # :nodoc:
      (@points.map{ |point| point.to_s } + [ @points.first ]).join( ' ' )
    end

    def inspect # :nodoc:
      "(#{ @points.map{|point| point.inspect}.join(', ')})"
    end

    def to_xml_element # :nodoc:
      xml_element = REXML::Element.new( XML_ELEMENT_NAME )
      xml_element.add_text( self.to_s )
      xml_element
    end

		# Two polygons are equivalent if their collection of points is equivalent.
    def ==( other )
      self.points == other.points
    end

    def self.parse_polygon_string( polygon_string ) # :nodoc:
      polygon_string.split( ' ' ).map{ |coordinate_string| coordinate_string.split( ',' ).map{|coordinate| coordinate.to_f }}
    end

    def self.from_xml_element( polygon_xml_element ) # :nodoc:
      coordinates = self.parse_polygon_string( polygon_xml_element.text )
      points = coordinates.map{ |lattitude, longitude| RCAP::Point.new( :lattitude => lattitude, :longitude => longitude )}[0..-2]
      polygon = self.new( :points => points )
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
rcap-0.1	lib/rcap/polygon.rb