require 'nokogiri' module GeoRuby module Gpx4r # An interface to GPX files class GpxFile attr_reader :record_count, :file_root #:xmin, :ymin, :xmax, :ymax, :zmin, :zmax, :mmin, :mmax, :file_length include Enumerable # Opens a GPX file. Both "abc.shp" and "abc" are accepted. def initialize(file, *opts) # with_z = true, with_m = true) @file_root = file.gsub(/\.gpx$/i, '') fail MalformedGpxException.new('Missing GPX File') unless File.exist? @file_root + '.gpx' @points, @envelope = [], nil @gpx = File.open(@file_root + '.gpx', 'rb') opt = opts.reduce({}) { |a, e| e.merge(a) } parse_file(opt[:with_z], opt[:with_m]) end # force the reopening of the files compsing the shp. Close before calling this. def reload! initialize(@file_root) end # opens a GPX "file". If a block is given, the GpxFile object is yielded to it and is closed upon return. Else a call to open is equivalent to GpxFile.new(...). def self.open(file, *opts) gpxfile = GpxFile.new(file, *opts) if block_given? yield gpxfile # gpxfile.close else gpxfile end end # Closes a gpxfile def close @gpx.close end # Tests if the file has no record def empty? record_count == 0 end # Goes through each record def each (0...record_count).each do |i| yield get_record(i) end end alias_method :each_record, :each # Returns record +i+ def [](i) get_record(i) end # Returns all the records def records @points end # Return the GPX file as LineString def as_line_string GeoRuby::SimpleFeatures::LineString.from_points(@points) end alias_method :as_polyline, :as_line_string # Return the GPX file as a Polygon # If the GPX isn't closed, a line from the first # to the last point will be created to close it. def as_polygon GeoRuby::SimpleFeatures::Polygon.from_points([@points[0] == @points[-1] ? @points : @points.push(@points[0].clone)]) end # Return GPX Envelope def envelope @envelope ||= as_polygon.envelope end private def get_record(i) @points[i] end # wpt => waypoint => TODO? # rte(pt) => route # trk(pt) => track / def parse_file(with_z, with_m) data = @gpx.read @file_mode = data =~ /trkpt/ ? '//trkpt' : (data =~ /wpt/ ? '//wpt' : '//rtept') Nokogiri.HTML(data).search(@file_mode).each do |tp| z = z.inner_text.to_f if with_z && z = tp.at('ele') m = m.inner_text if with_m && m = tp.at('time') @points << GeoRuby::SimpleFeatures::Point.from_coordinates([tp['lon'].to_f, tp['lat'].to_f, z, m], 4326, with_z, with_m) end close @record_count = @points.length envelope rescue => e raise MalformedGpxException.new("Bad GPX. Error: #{e}") # trackpoint.at("gpxdata:hr").nil? # heartrate end end class MalformedGpxException < StandardError end end end