declarative syntax does not work with column_mapped_collection

[Former user]

Using SA 0.5.0rc1.

I am using a pattern which boils down to this:

from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import orm
from sqlalchemy import schema
from sqlalchemy import types
from sqlalchemy.orm import collections

BaseObject = declarative_base()

class Foo(BaseObject):
    __tablename__ = "foo"
    id = schema.Column(types.Integer(), primary_key=True, autoincrement=True)

class Bar(BaseObject):
    __tablename__ = "bar"
    id = schema.Column(types.Integer(), primary_key=True, autoincrement=True)
    foos = orm.relation(Foo, lazy=False,
       collection_class=collections.column_mapped_collection(Foo.id))

this results in an error when initializing my models:

  File "/local/buildout/eggs/tmpEDqA0a/SQLAlchemy-0.5.0rc1-py2.5.egg/sqlalchemy/orm/collections.py", line 140, in column_mapped_collection
TypeError: '_CompileOnAttr' object is not iterable

[Former user]

Relevant irc comments:

16:26 <jek> Foo.id is not a Column
16:27 <jek> Foo.__table__.c.id is what you're looking for there
16:27 <zzzeek_> jek: we should put converters there
16:28 <zzzeek_> i.e. to call __clause_element__()

as an alternative you can also use attribute_mapped_column("id") here.

[Mike Bayer]

heres a patch:

Index: lib/sqlalchemy/orm/properties.py
===================================================================
--- lib/sqlalchemy/orm/properties.py    (revision 5124)
+++ lib/sqlalchemy/orm/properties.py    (working copy)
@@ -18,7 +18,7 @@
 from sqlalchemy.orm import (
     attributes, dependency, mapper, object_mapper, strategies,
     )
-from sqlalchemy.orm.util import CascadeOptions, _class_to_mapper, _orm_annotate
+from sqlalchemy.orm.util import CascadeOptions, _class_to_mapper, _orm_annotate, _configurational_column_spec
 from sqlalchemy.orm.interfaces import (
     MANYTOMANY, MANYTOONE, MapperProperty, ONETOMANY, PropComparator,
     StrategizedProperty,
@@ -546,16 +546,12 @@
             raise sa_exc.ArgumentError("relation '%s' expects a class or a mapper argument (received: %s)" % (self.key, type(self.argument)))
         assert isinstance(self.mapper, mapper.Mapper), self.mapper

-        # accept callables for other attributes which may require deferred initialization
-        for attr in ('order_by', 'primaryjoin', 'secondaryjoin', 'secondary', '_foreign_keys', 'remote_side'):
-            if callable(getattr(self, attr)):
-                setattr(self, attr, getattr(self, attr)())
-        
-        if self.order_by:
-            self.order_by = [for x in util.to_list(self.order_by)](expression._literal_as_column(x))
-        
-        self._foreign_keys = set(expression._literal_as_column(x) for x in util.to_set(self._foreign_keys))
-        self.remote_side = set(expression._literal_as_column(x) for x in util.to_set(self.remote_side))
+        self.order_by = _configurational_column_spec(self.order_by, util.to_list)
+        self.secondary = _configurational_column_spec(self.secondary)
+        self.primaryjoin = _configurational_column_spec(self.primaryjoin)
+        self.secondaryjoin = _configurational_column_spec(self.secondaryjoin)
+        self._foreign_keys = _configurational_column_spec(self._foreign_keys, util.to_set)
+        self.remote_side = _configurational_column_spec(self.remote_side, util.to_set)

         if not self.parent.concrete:
             for inheriting in self.parent.iterate_to_root():
Index: lib/sqlalchemy/orm/util.py
===================================================================
--- lib/sqlalchemy/orm/util.py  (revision 5124)
+++ lib/sqlalchemy/orm/util.py  (working copy)
@@ -459,6 +459,28 @@
 def _state_mapper(state):
     return state.manager.mapper

+def _configurational_column_spec(expr, filter=None):
+    """Perform argument conversions on a column-based configurational expression."""
+
+    # interpret callables passed by declarative
+    if callable(expr):
+        expr = expr()
+    
+    # "False" is our current "use the default" symbol
+    if expr is False:
+        return expr
+    
+    if expr is None:
+        ret = None
+    elif isinstance(expr, (tuple, list, set)):
+        ret = [for x in expr](_configurational_column_spec(x))
+    else:
+        
+        ret = expression._literal_as_column(expr)
+    if filter:
+        ret = filter(ret)
+    return ret
+
 def object_mapper(object, raiseerror=True):
     """Given an object, return the primary Mapper associated with the object instance.

Index: lib/sqlalchemy/orm/collections.py
===================================================================
--- lib/sqlalchemy/orm/collections.py   (revision 5124)
+++ lib/sqlalchemy/orm/collections.py   (working copy)
@@ -105,9 +105,9 @@

 import sqlalchemy.exceptions as sa_exc
 from sqlalchemy import schema
+from sqlalchemy.sql import expression
 import sqlalchemy.util as sautil

-
 __all__ = ['collection_adapter',
            'mapped_collection', 'column_mapped_collection',
            'attribute_mapped_collection']('collection',)
@@ -127,9 +127,12 @@
     after a session flush.

     """
-    from sqlalchemy.orm.util import _state_mapper
+    from sqlalchemy.orm.util import _state_mapper, _configurational_column_spec
     from sqlalchemy.orm.attributes import instance_state

+
+    mapping_spec = _configurational_column_spec(mapping_spec)
+    
     if isinstance(mapping_spec, schema.Column):
         def keyfunc(value):
             state = instance_state(value)

[Mike Bayer]

I just re-noticed that patch above, for now went with something simpler in 9b360dda29f5dbf260d27f43247b1adc9298c51a. It doesn't yet support string-based arguments.

[Mike Bayer]

Removing milestone: 0.5.0 (automated comment)