Use trace instead of gpx_id in queries

This makes the queries easier to read.

app/models/trace.rb

@@ -209,7 +209,7 @@ def import
  first = true
 
  # If there are any existing points for this trace then delete them
- Tracepoint.where(:gpx_id => id).delete_all
+ Tracepoint.where(:trace => id).delete_all
 
  gpx.points.each_slice(1_000) do |points|
  # Gather the trace points together for a bulk import
@@ -242,10 +242,10 @@ def import
  end
 
  if gpx.actual_points.positive?
- max_lat = Tracepoint.where(:gpx_id => id).maximum(:latitude)
- min_lat = Tracepoint.where(:gpx_id => id).minimum(:latitude)
- max_lon = Tracepoint.where(:gpx_id => id).maximum(:longitude)
- min_lon = Tracepoint.where(:gpx_id => id).minimum(:longitude)
+ max_lat = Tracepoint.where(:trace => id).maximum(:latitude)
+ min_lat = Tracepoint.where(:trace => id).minimum(:latitude)
+ max_lon = Tracepoint.where(:trace => id).maximum(:longitude)
+ min_lon = Tracepoint.where(:trace => id).minimum(:longitude)
 
  max_lat = max_lat.to_f / 10000000
  min_lat = min_lat.to_f / 10000000

test/models/trace_test.rb

@@ -193,16 +193,16 @@ def test_import_removes_previous_tracepoints
 
  def test_import_creates_tracepoints
  trace = create(:trace, :fixture => "a")
- assert_equal 0, Tracepoint.where(:gpx_id => trace.id).count
+ assert_equal 0, Tracepoint.where(:trace => trace).count
 
  trace.import
 
  trace.reload
- assert_equal 1, Tracepoint.where(:gpx_id => trace.id).count
+ assert_equal 1, Tracepoint.where(:trace => trace).count
 
  # Check that the tile has been set prior to the bulk import
  # i.e. that the callbacks have been run correctly
- assert_equal 3221331576, Tracepoint.where(:gpx_id => trace.id).first.tile
+ assert_equal 3221331576, Tracepoint.where(:trace => trace).first.tile
  end
 
  def test_import_creates_icon