Make pokedex work with SQLAlchemy 0.7. Warning: ugly hack!

[zzz-pokedex.git] / pokedex / db / multilang.py

diff --git a/pokedex/db/multilang.py b/pokedex/db/multilang.py
index d58f6df..d027d13 100644 (file)
--- a/pokedex/db/multilang.py
+++ b/pokedex/db/multilang.py
@@ -5,8 +5,9 @@ from sqlalchemy.orm import aliased, compile_mappers, mapper, relationship, synon
 from sqlalchemy.orm.collections import attribute_mapped_collection
 from sqlalchemy.orm.scoping import ScopedSession
 from sqlalchemy.orm.session import Session, object_session
+from sqlalchemy.engine.base import Connection
 from sqlalchemy.schema import Column, ForeignKey, Table
-from sqlalchemy.sql.expression import and_, bindparam, select
+from sqlalchemy.sql.expression import and_, bindparam, select, Select
 from sqlalchemy.types import Integer
 
 def create_translation_table(_table_name, foreign_class, relation_name,
@@ -157,46 +158,40 @@ 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)
-        return super(MultilangSession, self).execute(
-            clause, params, *args, **kwargs)
+    def connection(self, *args, **kwargs):
+        """Monkeypatch the connection. Not pretty at all.
+        """
+        conn = super(MultilangSession, self).connection(*args, **kwargs)
+        original_execute = conn.execute
+        if original_execute.__name__ != 'monkeypatched_execute':
+            def monkeypatched_execute(statement, *multiparams, **params):
+                if isinstance(statement, Select):
+                    boundparams = dict(multiparams[0])
+                    boundparams.setdefault('_default_language_id', self.default_language_id)
+                    multiparams = [boundparams] + list(multiparams[1:])
+                return original_execute(statement, *multiparams, **params)
+            conn.execute = monkeypatched_execute
+        return conn
 
 class MultilangScopedSession(ScopedSession):
     """Dispatches language selection to the attached Session."""
 
     @property
-    def default_language(self):
-        return self.registry().default_language
-
-    @default_language.setter
-    def default_language(self, new):
-        self.registry().default_language = new
+    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