Fix default language assignment once and for all.

Stop trying to be clever and magical and just make the caller pass in a
damn primary key.

pokedex/db/__init__.py

@@ -7,6 +7,8 @@ from ..defaults import get_default_db_uri
 from .tables import Language, metadata
 from .multilang import MultilangSession, MultilangScopedSession
 
+ENGLISH_ID = 9
+
 
 def connect(uri=None, session_args={}, engine_args={}, engine_prefix=''):
     """Connects to the requested URI.  Returns a session object.
@@ -44,15 +46,10 @@ def connect(uri=None, session_args={}, engine_args={}, engine_prefix=''):
 
     all_session_args = dict(autoflush=True, autocommit=False, bind=engine)
     all_session_args.update(session_args)
-    sm = orm.sessionmaker(class_=MultilangSession, language_class=Language,
-        **all_session_args)
+    sm = orm.sessionmaker(class_=MultilangSession,
+        default_language_id=ENGLISH_ID, **all_session_args)
     session = MultilangScopedSession(sm)
 
-    # Default to English.  Warning, magic constant, messing with internals,
-    # blah blah.  Trying to fetch English here would kinda break on new
-    # databases.  TODO still not an ideal solution, I guess.
-    session.registry()._default_language_id = 9
-
     return session
 
 def identifier_from_name(name):

pokedex/db/multilang.py

@@ -157,46 +157,36 @@ def create_translation_table(_table_name, foreign_class, relation_name,
 class MultilangSession(Session):
     """A tiny Session subclass that adds support for a default language.
 
-    Caller will need to assign something to `default_language` before this will
-    actually work.
+    Needs to be used with `MultilangScopedSession`, below.
     """
-    _default_language_id = 0  # Better fill this in, caller
+    default_language_id = None
 
     def __init__(self, *args, **kwargs):
-        self.language_class = kwargs.pop('language_class')
+        if 'default_language_id' in kwargs:
+            self.default_language_id = kwargs.pop('default_language_id')
+
         super(MultilangSession, self).__init__(*args, **kwargs)
 
-    @property
-    def default_language(self):
-        return self.query(self.language_class) \
-            .filter_by(id=self._default_language_id) \
-            .one()
-
-    @default_language.setter
-    def default_language(self, new):
-        self._default_language_id = new.id
-
-    @default_language.deleter
-    def default_language(self):
-        try:
-            del self._default_language_id
-        except AttributeError:
-            pass
-
     def execute(self, clause, params=None, *args, **kwargs):
         if not params:
             params = {}
-        params.setdefault('_default_language_id', self._default_language_id)
+        params.setdefault('_default_language_id', self.default_language_id)
+
         return super(MultilangSession, self).execute(
             clause, params, *args, **kwargs)
 
 class MultilangScopedSession(ScopedSession):
     """Dispatches language selection to the attached Session."""
 
-    @property
-    def default_language(self):
-        return self.registry().default_language
+    def __init__(self, *args, **kwargs):
+        super(MultilangScopedSession, self).__init__(*args, **kwargs)
 
-    @default_language.setter
-    def default_language(self, new):
-        self.registry().default_language = new
+    @property
+    def default_language_id(self):
+        """Passes the new default language id through to the current session.
+        """
+        return self.registry().default_language_id
+
+    @default_language_id.setter
+    def default_language_id(self, new):
+        self.registry().default_language_id = new

pokedex/tests/test_schema.py

@@ -66,7 +66,7 @@ def test_i18n_table_creation():
 
     # OK, create all the tables and gimme a session
     Base.metadata.create_all()
-    sm = sessionmaker(class_=MultilangSession, language_class=Language)
+    sm = sessionmaker(class_=MultilangSession)
     sess = MultilangScopedSession(sm)
 
     # Create some languages and foos to bind together
@@ -80,9 +80,12 @@ def test_i18n_table_creation():
     foo = Foo()
     sess.add(foo)
 
-    # Commit so the above get primary keys filled in
+    # Commit so the above get primary keys filled in, then give the
+    # session the language id
     sess.commit()
-    sess.default_language = lang_en
+    # Note that this won't apply to sessions created in other threads, but that
+    # ought not be a problem!
+    sess.default_language_id = lang_en.id
 
     # Give our foo some names, as directly as possible
     foo_text = FooText()