merge areas

src/c3nav/mapdata/migrations/0045_merge_areas.py

@@ -0,0 +1,37 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.4 on 2017-05-04 12:52
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+def merge_areas(apps, schema_editor):
+    from shapely.ops import cascaded_union
+    Level = apps.get_model('mapdata', 'Level')
+    for level in Level.objects.all():
+        level_areas = list(level.areas.all())
+        while level_areas:
+            current_area = level_areas.pop(0)
+            while True:
+                for area in level_areas[:]:
+                    if area.geometry.intersects(current_area.geometry) and current_area.public == area.public:
+                        current_area.geometry = cascaded_union([area.geometry, current_area.geometry])
+                        current_area.save()
+                        level_areas.remove(area)
+                        area.delete()
+                        break
+                else:
+                    break
+
+    return
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('mapdata', '0044_auto_20170504_1023'),
+    ]
+
+    operations = [
+        migrations.RunPython(merge_areas),
+    ]