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 b5f87e4..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,
@@ -99,7 +100,8 @@ def create_translation_table(_table_name, foreign_class, relation_name,
         'foreign_id': synonym(foreign_key_name),
         'local_language': relationship(language_class,
             primaryjoin=table.c.local_language_id == language_class.id,
-            innerjoin=True),
+            innerjoin=True,
+            lazy='joined'),
     })
 
     # Add full-table relations to the original class
@@ -154,46 +156,42 @@ def create_translation_table(_table_name, foreign_class, relation_name,
     return Translations
 
 class MultilangSession(Session):
-    """A tiny Session subclass that adds support for a default language."""
-    _default_language_id = 9  # English.  XXX magic constant
+    """A tiny Session subclass that adds support for a default language.
 
-    @property
-    def default_language(self):
-        # Need to import tables here to avoid a circular dependency
-        from pokedex.db import tables
-        query = self.query(tables.Language)
-        query = query.filter_by(id=self._default_language_id)
-        return query.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)
+    Needs to be used with `MultilangScopedSession`, below.
+    """
+    default_language_id = None
+
+    def __init__(self, *args, **kwargs):
+        if 'default_language_id' in kwargs:
+            self.default_language_id = kwargs.pop('default_language_id')
+
+        super(MultilangSession, self).__init__(*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 remove(self):
-        del self.registry().default_language
-        super(MultilangScopedSession, self).remove()
+    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