Add justified photo grid layout with lazy loading and image dimensions.

photologue/migrations/0008_photo_dimensions.py

@@ -0,0 +1,45 @@
+import photologue.models
+from django.db import migrations, models
+
+
+def fill_dimensions(apps, schema_editor):
+    Photo = apps.get_model('photologue', 'Photo')
+    for photo in Photo.objects.filter(image_width__isnull=True).iterator():
+        try:
+            photo.image_width = photo.image.width
+            photo.image_height = photo.image.height
+            photo.save(update_fields=['image_width', 'image_height'])
+        except Exception:
+            pass
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('photologue', '0007_allow_duplicate_photo_titles'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='photo',
+            name='image_width',
+            field=models.PositiveIntegerField(editable=False, null=True),
+        ),
+        migrations.AddField(
+            model_name='photo',
+            name='image_height',
+            field=models.PositiveIntegerField(editable=False, null=True),
+        ),
+        migrations.RunPython(fill_dimensions, migrations.RunPython.noop),
+        migrations.AlterField(
+            model_name='photo',
+            name='image',
+            field=models.ImageField(
+                max_length=100,
+                upload_to=photologue.models.get_storage_path,
+                verbose_name='image',
+                width_field='image_width',
+                height_field='image_height',
+            ),
+        ),
+    ]