Update system settings from db in development also #11660

arches/app/models/system_settings.py

@@ -22,6 +22,9 @@
 from arches.app.models import models
 
 
+tiles_loaded = False
+
+
 class SystemSettings(LazySettings):
     """
     This class can be used just like you would use settings.py
@@ -33,16 +36,13 @@ class SystemSettings(LazySettings):
         settings.SEARCH_ITEMS_PER_PAGE
 
         # will list all settings
-        print settings
+        print(settings)
 
     """
 
     SYSTEM_SETTINGS_RESOURCE_MODEL_ID = "ff623370-fa12-11e6-b98b-6c4008b05c4c"
     RESOURCE_INSTANCE_ID = "a106c400-260c-11e7-a604-14109fd34195"
 
-    def __init__(self, *args, **kwargs):
-        super(SystemSettings, self).__init__(*args, **kwargs)
-
     def __str__(self):
         ret = []
         for setting in dir(self):
@@ -53,24 +53,21 @@ def __str__(self):
 
     def __getattr__(self, name):
         """
-        By default get settings from this class which is initially populated from the settings.py filter
-        If a setting is requested that isn't found, assume it's saved in the database and try and retrieve it from there
-        by calling update_from_db first which populates this class with any settings from the database
-
-        What this means is that update_from_db will only be called once a setting is requested that isn't initially in the settings.py file
-        Only then will settings from the database be applied (and potentially overwrite settings found in settings.py)
-
+        Defer loading of system settings tiles until first access.
+        An effort toward avoiding module-level queries, which are discouraged:
+        https://docs.djangoproject.com/stable/ref/applications/#troubleshooting
         """
-
-        try:
-            return super(SystemSettings, self).__getattr__(name)
-        except ImproperlyConfigured:
-            raise
-        except:
-            self.update_from_db()
-            return super(SystemSettings, self).__getattr__(
-                name
-            )  # getattr(self, name, True)
+        global tiles_loaded
+        if not tiles_loaded:
+            # Optimistically set this True to avoid concurrent queries.
+            tiles_loaded = True
+            try:
+                self.update_from_db()
+            except ImportError:
+                # Circular imports. Try again later.
+                tiles_loaded = False
+
+        return super().__getattr__(name)
 
     def setting_exists(self, name):
         """