Add exceptions.DatabaseOutOfDate instead of just using an error string.

And don't raise SystemExit. Not sure what I was thinking.

etiquette/constants.py

@@ -110,11 +110,6 @@ SQL_USER = _sql_dictify(SQL_USER_COLUMNS)
 
 
 # Errors and warnings
-ERROR_DATABASE_OUTOFDATE = '''
-Database is out-of-date. {current} should be {new}.
-Please use utilities\\etiquette_upgrader.py
-'''.strip()
-
 WARNING_MINMAX_INVALID = 'Field "{field}": "{value}" is not a valid request. Ignored.'
 WARNING_ORDERBY_INVALID = 'Invalid orderby request "{request}". Ignored.'
 WARNING_ORDERBY_BADCOL = '"{column}" is not a sorting option. Ignored.'

etiquette/exceptions.py

@@ -124,6 +124,16 @@ class WrongLogin(EtiquetteException):
 
 
 # GENERAL ERRORS
+OUTOFDATE = '''
+Database is out of date. {current} should be {new}.
+Please use utilities\\etiquette_upgrader.py
+'''.strip()
+class DatabaseOutOfDate(EtiquetteException):
+    '''
+    Raised by PhotoDB __init__ if the user's database is behind.
+    '''
+    error_message = OUTOFDATE
+
 class FeatureDisabled(EtiquetteException):
     '''
     For when features of the system have been disabled by the configuration.

etiquette/photodb.py

@@ -1113,9 +1113,7 @@ class PhotoDB(PDBAlbumMixin, PDBBookmarkMixin, PDBPhotoMixin, PDBTagMixin, PDBUs
             self.cur.execute('PRAGMA user_version')
             existing_version = self.cur.fetchone()[0]
             if existing_version != DATABASE_VERSION:
-                message = constants.ERROR_DATABASE_OUTOFDATE
-                message = message.format(current=existing_version, new=DATABASE_VERSION)
-                raise SystemExit(message)
+                raise exceptions.DatabaseOutOfDate(current=existing_version, new=DATABASE_VERSION)
 
         statements = DB_INIT.split(';')
         for statement in statements: