use customized constance (#4191)

thirdpart/constance/checks.py

@@ -0,0 +1,42 @@
+from django.core import checks
+from django.utils.translation import ugettext_lazy as _
+
+from . import settings
+
+
+@checks.register("constance")
+def check_fieldsets(*args, **kwargs):
+    """
+    A Django system check to make sure that, if defined, CONFIG_FIELDSETS accounts for
+    every entry in settings.CONFIG.
+    """
+    if hasattr(settings, "CONFIG_FIELDSETS") and settings.CONFIG_FIELDSETS:
+        inconsistent_fieldnames = get_inconsistent_fieldnames()
+        if inconsistent_fieldnames:
+            return [
+                checks.Warning(
+                    _(
+                        "CONSTANCE_CONFIG_FIELDSETS is missing "
+                        "field(s) that exists in CONSTANCE_CONFIG."
+                    ),
+                    hint=", ".join(sorted(inconsistent_fieldnames)),
+                    obj="settings.CONSTANCE_CONFIG",
+                    id="constance.E001",
+                )
+            ]
+    return []
+
+
+def get_inconsistent_fieldnames():
+    """
+    Returns a set of keys from settings.CONFIG that are not accounted for in
+    settings.CONFIG_FIELDSETS.
+    If there are no fieldnames in settings.CONFIG_FIELDSETS, returns an empty set.
+    """
+    field_name_list = []
+    for fieldset_title, fields_list in settings.CONFIG_FIELDSETS.items():
+        for field_name in fields_list:
+            field_name_list.append(field_name)
+    if not field_name_list:
+        return {}
+    return set(set(settings.CONFIG.keys()) - set(field_name_list))