app/controllers/api/tracepoints_controller.rb

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