app/controllers/api/tracepoints_controller.rb

   1 module Api
   2   class TracepointsController < ApiController
   3     authorize_resource
   4
   5     before_action :check_api_readable
   6     around_action :api_call_handle_error, :api_call_timeout
   7
   8     # Get an XML response containing a list of tracepoints that have been uploaded
   9     # within the specified bounding box, and in the specified page.
  10     def index
  11       # retrieve the page number
  12       page = params["page"].to_s.to_i
  13
  14       unless page >= 0
  15         report_error("Page number must be greater than or equal to 0")
  16         return
  17       end
  18
  19       offset = page * Settings.tracepoints_per_page
  20
  21       # Figure out the bbox
  22       # check boundary is sane and area within defined
  23       # see /config/application.yml
  24       begin
  25         bbox = BoundingBox.from_bbox_params(params)
  26         bbox.check_boundaries
  27         bbox.check_size
  28       rescue StandardError => e
  29         report_error(e.message)
  30         return
  31       end
  32
  33       # get all the points
  34       ordered_points = Tracepoint.bbox(bbox).joins(:trace).where(:gpx_files => { :visibility => %w[trackable identifiable] }).order("gpx_id DESC, trackid ASC, timestamp ASC")
  35       unordered_points = Tracepoint.bbox(bbox).joins(:trace).where(:gpx_files => { :visibility => %w[public private] }).order("gps_points.latitude", "gps_points.longitude", "gps_points.timestamp")
  36       points = ordered_points.union_all(unordered_points).offset(offset).limit(Settings.tracepoints_per_page).preload(:trace)
  37
  38       doc = XML::Document.new
  39       doc.encoding = XML::Encoding::UTF_8
  40       root = XML::Node.new "gpx"
  41       root["version"] = "1.0"
  42       root["creator"] = "OpenStreetMap.org"
  43       root["xmlns"] = "http://www.topografix.com/GPX/1/0"
  44
  45       doc.root = root
  46
  47       # initialise these variables outside of the loop so that they
  48       # stay in scope and don't get free'd up by the GC during the
  49       # loop.
  50       gpx_id = -1
  51       trackid = -1
  52       track = nil
  53       trkseg = nil
  54       anon_track = nil
  55       anon_trkseg = nil
  56       timestamps = false
  57
  58       points.each do |point|
  59         if gpx_id != point.gpx_id
  60           gpx_id = point.gpx_id
  61           trackid = -1
  62
  63           if point.trace.trackable?
  64             track = XML::Node.new "trk"
  65             doc.root << track
  66             timestamps = true
  67
  68             if point.trace.identifiable?
  69               track << (XML::Node.new("name") << point.trace.name)
  70               track << (XML::Node.new("desc") << point.trace.description)
  71               track << (XML::Node.new("url") << url_for(:controller => "/traces", :action => "show", :display_name => point.trace.user.display_name, :id => point.trace.id))
  72             end
  73           else
  74             # use the anonymous track segment if the user hasn't allowed
  75             # their GPX points to be tracked.
  76             timestamps = false
  77             if anon_track.nil?
  78               anon_track = XML::Node.new "trk"
  79               doc.root << anon_track
  80             end
  81             track = anon_track
  82           end
  83         end
  84
  85         if trackid != point.trackid
  86           if point.trace.trackable?
  87             trkseg = XML::Node.new "trkseg"
  88             track << trkseg
  89             trackid = point.trackid
  90           else
  91             if anon_trkseg.nil?
  92               anon_trkseg = XML::Node.new "trkseg"
  93               anon_track << anon_trkseg
  94             end
  95             trkseg = anon_trkseg
  96           end
  97         end
  98
  99         trkseg << point.to_xml_node(timestamps)
 100       end
 101
 102       response.headers["Content-Disposition"] = "attachment; filename=\"tracks.gpx\""
 103
 104       render :xml => doc.to_s
 105     end
 106   end
 107 end