Add documentation and source

Added documentation, source and extra files.

source/advanced/various/admin/room.py

@@ -0,0 +1,51 @@
+from django.contrib import admin
+from django.db import models
+from django.db.models import F
+from django.http import HttpRequest
+from django.utils.translation import gettext_lazy as _
+
+from various.models import Room
+
+
+@admin.register(Room)
+class RoomAdmin(admin.ModelAdmin):
+    """
+    Admin configuration for rooms.
+
+    """
+
+    list_display = ["id", "name", "length", "width", "height", "get_volume_display"]
+    list_editable = ["name", "length", "width", "height"]
+    actions = ["action_fix_minimum"]
+
+    def get_queryset(self, request):
+        """
+        Change queryset to add a computed field for volume.
+
+        Args:
+            request: HTTP
+
+        """
+        return super().get_queryset(request).annotate(volume=F("width") * F("length") * F("height"))
+
+    def get_volume_display(self, obj: Room) -> str:
+        return f"{obj.get_volume()} cm³"
+
+    get_volume_display.short_description = _("area")
+    get_volume_display.admin_order_field = "volume"
+
+    def action_fix_minimum(self, request: HttpRequest, queryset: models.QuerySet):
+        """
+        Change room dimensions to have at least 1cm in every axis.
+
+        Args:
+            request: HTTP request.
+            queryset: selected rooms.
+
+        """
+        for room in queryset:  # type: Room
+            room.width = max(1, room.width)
+            room.length = max(1, room.length)
+            room.height = max(1, room.height)
+            room.save()
+        self.message_user(request, _("The selected rooms have been updated."))