feat: clock + place games

polylan_submitter/place/signals.py

@@ -0,0 +1,37 @@
+"""Reacts to an admin editing a PlaceSettings row (grid size) by:
+
+1. Rebuilding that event's Redis canvas from history at the (possibly new)
+   dimensions - a resize invalidates the old Redis bytes (wrong length,
+   wrong meaning), so this keeps Redis self-healing instead of relying on
+   the admin remembering to click "Resync canvas from DB" after every
+   resize.
+2. Pushing the new size to that event's already-connected clients. Unlike
+   the clock app, place has no periodic heartbeat broadcast to piggyback
+   this onto, so it's broadcast explicitly here instead.
+"""
+
+from asgiref.sync import async_to_sync
+from channels.layers import get_channel_layer
+from django.db.models.signals import post_save
+from django.dispatch import receiver
+
+from .broadcast import place_group
+from .canvas import rebuild_canvas_from_history
+from .models import PlaceSettings
+
+
+@receiver(post_save, sender=PlaceSettings)
+def on_settings_saved(sender, instance, **kwargs):
+    rebuild_canvas_from_history(instance.event, instance.width, instance.height)
+
+    channel_layer = get_channel_layer()
+    if channel_layer is None:
+        return
+    async_to_sync(channel_layer.group_send)(
+        place_group(instance.event.path),
+        {
+            "type": "settings_changed",
+            "width": instance.width,
+            "height": instance.height,
+        },
+    )