app/controllers/api/tracepoints_controller.rb

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