Allow to disable filter support for meta properties (#2901)

src/pretix/base/migrations/0224_eventmetaproperty_filter_allowed.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.2.16 on 2022-11-14 11:32
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0223_voucher_min_usages'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='eventmetaproperty',
+            name='filter_allowed',
+            field=models.BooleanField(default=True),
+        ),
+    ]

src/pretix/base/models/event.py

@@ -1580,6 +1580,11 @@ class EventMetaProperty(LoggedModel):
         verbose_name=_("Valid values"),
         help_text=_("If you keep this empty, any value is allowed. Otherwise, enter one possible value per line.")
     )
+    filter_allowed = models.BooleanField(
+        default=True, verbose_name=_("Can be used for filtering"),
+        help_text=_("This field will be shown to filter events or reports in the backend, and it can also be used "
+                    "for hidden filter parameters in the frontend (e.g. using the widget).")
+    )
 
     def full_clean(self, exclude=None, validate_unique=True):
         super().full_clean(exclude, validate_unique)