Merge pull request #386 from gtt-project/feat/geojson-precision

feat: configurable GeoJSON coordinate precision (default 6)

Author: dkastl

app/views/settings/gtt/_general.html.erb

@@ -79,3 +79,11 @@
   <%= content_tag(:label, l(:label_hide_map_for_invalid_geom)) %>
   <%= check_box_tag 'settings[hide_map_for_invalid_geom]', 1, Setting.plugin_redmine_gtt['hide_map_for_invalid_geom'] %>
 </p>
+
+<p>
+  <%= content_tag(:label, l(:label_geojson_precision)) %>
+  <%= number_field_tag('settings[geojson_precision]',
+      @settings['geojson_precision'],
+      min: 0, max: 15, step: 1) %>
+  <em class="info"><%= l(:text_geojson_precision_info) %></em>
+</p>

config/locales/de.yml

@@ -121,6 +121,8 @@ de:
   field_format: Format-Typ
   select_other_gtt_settings: Andere GTT-Einstellungen
   label_hide_map_for_invalid_geom: Ausblenden der Ausgabekarte für ungültige Geometrie
+  label_geojson_precision: "GeoJSON-Koordinatengenauigkeit"
+  text_geojson_precision_info: "Nachkommastellen der Koordinaten in der GeoJSON-Ausgabe (EPSG:4326). 6 entspricht etwa 0,11 m; kleinere Werte verringern die Datenmenge."
   gtt_hide_map_for_invalid_geom_info: Bitte bearbeiten Sie die Anfrage und stellen
     Sie die Geometrie ein, um die Karte zu sehen.
   label_default_measure_enabled: Zeige Steuerung zum Messen von Länge und Fläche

config/locales/en.yml

@@ -60,6 +60,8 @@ en:
 
   select_other_gtt_settings: "Other GTT settings"
   label_hide_map_for_invalid_geom: "Hide issue map for invalid geometry"
+  label_geojson_precision: "GeoJSON coordinate precision"
+  text_geojson_precision_info: "Decimal places for coordinates in GeoJSON output (EPSG:4326). 6 is about 0.11 m; lower values shrink the payload."
   gtt_hide_map_for_invalid_geom_info: "Please edit the issue and set the geometry
     to see the map."
 

config/locales/ja.yml

@@ -58,6 +58,8 @@ ja:
 
   select_other_gtt_settings: "GTTのその他の設定"
   label_hide_map_for_invalid_geom: "位置情報が登録されていない時に地図を隠す"
+  label_geojson_precision: "GeoJSON座標の小数点桁数"
+  text_geojson_precision_info: "GeoJSON出力（EPSG:4326）の座標の小数点以下の桁数。6桁で約0.11m。小さくするとデータ量を削減できます。"
   gtt_hide_map_for_invalid_geom_info: "地図を見るにはチケットを編集して位置情報を登録してください。"
 
   select_default_tracker_icon: "トラッカーアイコンを選択:"

init.rb

@@ -34,7 +34,10 @@
       'editable_geometry_types_on_issue_map' => ["Point"],
       'enable_geojson_upload_on_issue_map' => false,
       'enable_geocoding_on_map' => false,
-      'hide_map_for_invalid_geom' => false
+      'hide_map_for_invalid_geom' => false,
+      # Keep in sync with RedmineGtt::DEFAULT_GEOJSON_PRECISION (literal here to
+      # avoid autoloading the module during plugin registration).
+      'geojson_precision' => 6
     },
     partial: 'settings/gtt/settings'
   )

lib/redmine_gtt.rb

@@ -2,6 +2,21 @@
 
 module RedmineGtt
 
+  # Number of decimal places GeoJSON coordinates are rounded to on output
+  # (EPSG:4326 degrees, so 6 digits is ~0.11 m, 7 ~1 cm). RGeo's encoder emits
+  # full float precision and upstream declines to add a precision option, so
+  # the plugin rounds itself; the default keeps payloads small without losing
+  # any real-world accuracy. Configurable via plugin settings; clamped so a
+  # bad value can never break SQL or produce absurd output.
+  DEFAULT_GEOJSON_PRECISION = 6
+  GEOJSON_PRECISION_RANGE = (0..15)
+
+  def self.geojson_precision
+    raw = Setting.plugin_redmine_gtt['geojson_precision']
+    value = Integer(raw, exception: false) || DEFAULT_GEOJSON_PRECISION
+    value.clamp(GEOJSON_PRECISION_RANGE.min, GEOJSON_PRECISION_RANGE.max)
+  end
+
   def self.setup_normal_patches
     RedmineGtt::Patches::IssuePatch.apply
     RedmineGtt::Patches::IssueQueryPatch.apply

lib/redmine_gtt/conversions.rb

@@ -10,25 +10,53 @@ module RedmineGtt
   module Conversions
 
     class GeomToJson
-      def initialize()
+      # RGeo's GeoJSON encoder emits full float precision and offers no
+      # rounding option (see gtt-project/redmine_gtt#7), so coordinates are
+      # rounded after encoding. Defaults to the configured plugin precision.
+      def initialize(precision: RedmineGtt.geojson_precision)
         @factory = RGeo::GeoJSON::EntityFactory.instance
+        @precision = precision
       end
 
       def to_json(object, id: nil, properties: nil)
-        RGeo::GeoJSON.encode feature(object, id, properties)
+        round_coordinates RGeo::GeoJSON.encode(feature(object, id, properties))
       end
 
       def collection_to_json(data)
-        RGeo::GeoJSON.encode @factory.feature_collection(
+        round_coordinates RGeo::GeoJSON.encode(@factory.feature_collection(
           data.map{|object, id, properties| feature(object, id, properties)}
-        )
+        ))
       end
 
       private
 
       def feature(object, id, properties = nil)
         @factory.feature object, id, (properties || {})
       end
+
+      # Walks the encoded GeoJSON and rounds the numbers under any
+      # "coordinates" key to @precision decimal places, leaving everything
+      # else (notably "properties") untouched.
+      def round_coordinates(node)
+        case node
+        when Hash
+          node.each_with_object({}) do |(key, value), result|
+            result[key] = key == 'coordinates' ? round_numbers(value) : round_coordinates(value)
+          end
+        when Array
+          node.map { |element| round_coordinates(element) }
+        else
+          node
+        end
+      end
+
+      def round_numbers(value)
+        case value
+        when Array then value.map { |element| round_numbers(element) }
+        when Numeric then value.round(@precision)
+        else value
+        end
+      end
     end
 
     class WkbToGeom

lib/redmine_gtt/patches/geojson_attribute.rb

@@ -24,7 +24,10 @@ def self.prepended(base)
       module ClassMethods
 
         def geojson_attribute_select
-          "ST_AsGeoJson(#{table_name}.geom) as db_geojson"
+          # maxdecimaldigits keeps coordinate precision (and payload size) in
+          # check; RedmineGtt.geojson_precision returns a clamped Integer so
+          # the interpolation is injection-safe.
+          "ST_AsGeoJson(#{table_name}.geom, #{RedmineGtt.geojson_precision}) as db_geojson"
         end
 
         def array_to_geojson(array, include_properties: false)

test/test_helper.rb

@@ -44,7 +44,13 @@ def assert_geojson(json)
   end
 
   def assert_equal_coordinates(a, b)
-    assert_equal a.flatten.map{|f|f.round 5}, b.flatten.map{|f|f.round 5}
+    # Compare at the precision GeoJSON output is actually rounded to (follows
+    # the configured setting, so it stays correct if a test changes it).
+    # Comparing at a lower precision than the output uses would double-round
+    # boundary values (e.g. 135.2528349 -> round(6) 135.252835 -> round(5)
+    # 135.25284, while a direct round(5) gives 135.25283).
+    precision = RedmineGtt.geojson_precision
+    assert_equal a.flatten.map{|f|f.round precision}, b.flatten.map{|f|f.round precision}
   end
 
   def assert_geojson_collection(json)

test/unit/issue_test.rb

@@ -74,12 +74,12 @@ class IssueTest < GttTest
     new_coordinates = old_coordinates.map{|c| c + 0.000000001}
     @issue.update_attribute :geojson, point_geojson(new_coordinates)
     @issue.instance_variable_set "@geojson", nil
-    assert_equal old_coordinates, @issue.geojson["geometry"]["coordinates"]
+    assert_equal_coordinates old_coordinates, @issue.geojson["geometry"]["coordinates"]
 
     new_coordinates = [old_coordinates[0] + 0.2, old_coordinates[1], old_coordinates[2]]
     @issue.update_attribute :geojson, point_geojson(new_coordinates)
     @issue.instance_variable_set "@geojson", nil
-    assert_equal new_coordinates, @issue.geojson["geometry"]["coordinates"]
+    assert_equal_coordinates new_coordinates, @issue.geojson["geometry"]["coordinates"]
   end
 
   test 'should ignore small linestring geom changes' do
@@ -92,18 +92,18 @@ class IssueTest < GttTest
     new_coordinates = old_coordinates.map{|c| [c[0] + 0.000000001, c[1] + 0.000000001, c[2]]}
     @issue.update_attribute :geojson, linestring_geojson(new_coordinates)
     @issue.instance_variable_set "@geojson", nil
-    assert_equal old_coordinates, @issue.geojson["geometry"]["coordinates"]
+    assert_equal_coordinates old_coordinates, @issue.geojson["geometry"]["coordinates"]
 
     new_coordinates = old_coordinates.map{|c| [c[0] + 0.2, c[1], c[2]]}
     @issue.update_attribute :geojson, linestring_geojson(new_coordinates)
     @issue.instance_variable_set "@geojson", nil
-    assert_equal new_coordinates, @issue.geojson["geometry"]["coordinates"]
+    assert_equal_coordinates new_coordinates, @issue.geojson["geometry"]["coordinates"]
 
     new_coordinates = old_coordinates.map{|c| [c[0], c[1], c[2]]}
     new_coordinates.delete_at(1)
     @issue.update_attribute :geojson, linestring_geojson(new_coordinates)
     @issue.instance_variable_set "@geojson", nil
-    assert_equal new_coordinates, @issue.geojson["geometry"]["coordinates"]
+    assert_equal_coordinates new_coordinates, @issue.geojson["geometry"]["coordinates"]
   end
 
   test 'should ignore small polygon geom changes' do
@@ -116,17 +116,17 @@ class IssueTest < GttTest
     new_coordinates = [old_coordinates[0].map{|c| [c[0] + 0.000000001, c[1] + 0.000000001, c[2]]}]
     @issue.update_attribute :geojson, polygon_geojson(new_coordinates)
     @issue.instance_variable_set "@geojson", nil
-    assert_equal old_coordinates, @issue.geojson["geometry"]["coordinates"]
+    assert_equal_coordinates old_coordinates, @issue.geojson["geometry"]["coordinates"]
 
     new_coordinates = [old_coordinates[0].map{|c| [c[0] + 0.2, c[1], c[2]]}]
     @issue.update_attribute :geojson, polygon_geojson(new_coordinates)
     @issue.instance_variable_set "@geojson", nil
-    assert_equal new_coordinates, @issue.geojson["geometry"]["coordinates"]
+    assert_equal_coordinates new_coordinates, @issue.geojson["geometry"]["coordinates"]
 
     new_coordinates = [old_coordinates[0].map{|c| [c[0], c[1], c[2]]}]
     new_coordinates[0].insert(2, [135.301041779,34.680969984,0.0])
     @issue.update_attribute :geojson, polygon_geojson(new_coordinates)
     @issue.instance_variable_set "@geojson", nil
-    assert_equal new_coordinates, @issue.geojson["geometry"]["coordinates"]
+    assert_equal_coordinates new_coordinates, @issue.geojson["geometry"]["coordinates"]
   end
 end