- [feature] Added new capability to relationship

loader options to allow "default" loader strategies.
Pass '*' to any of joinedload(), lazyload(),
subqueryload(), or noload() and that becomes the
loader strategy used for all relationships,
except for those explicitly stated in the
Query.  Thanks to up-and-coming contributor
Kent Bower for an exhaustive and well
written test suite !  [ticket:2351]

4 files changed, 29 insertions, 2 deletions

diff --git a/lib/sqlalchemy/orm/__init__.py b/lib/sqlalchemy/orm/__init__.py
index 58286e12b..9fd969e3b 100644
--- a/lib/sqlalchemy/orm/__init__.py
+++ b/lib/sqlalchemy/orm/__init__.py
@@ -1289,6 +1289,9 @@ def joinedload(*keys, **kw):
         # to joined-load across both, use joinedload_all()
         query(Order).options(joinedload_all(Order.items, Item.keywords))
 
+        # set the default strategy to be 'joined'
+        query(Order).options(joinedload('*'))
+
     :func:`joinedload` also accepts a keyword argument `innerjoin=True` which
     indicates using an inner join instead of an outer::
 
@@ -1360,6 +1363,7 @@ def joinedload_all(*keys, **kw):
     else:
         return strategies.EagerLazyOption(keys, lazy='joined', chained=True)
 
+
 def eagerload(*args, **kwargs):
     """A synonym for :func:`joinedload()`."""
     return joinedload(*args, **kwargs)
@@ -1388,6 +1392,9 @@ def subqueryload(*keys):
         # to subquery-load across both, use subqueryload_all()
         query(Order).options(subqueryload_all(Order.items, Item.keywords))
 
+        # set the default strategy to be 'subquery'
+        query(Order).options(subqueryload('*'))
+
     See also:  :func:`joinedload`, :func:`lazyload`
 
     """
diff --git a/lib/sqlalchemy/orm/interfaces.py b/lib/sqlalchemy/orm/interfaces.py
index f570c10c2..7f2875e5a 100644
--- a/lib/sqlalchemy/orm/interfaces.py
+++ b/lib/sqlalchemy/orm/interfaces.py
@@ -306,16 +306,24 @@ class StrategizedProperty(MapperProperty):
 
     """
 
+    strategy_wildcard_key = None
+
     def _get_context_strategy(self, context, reduced_path):
         key = ('loaderstrategy', reduced_path)
+        cls = None
         if key in context.attributes:
             cls = context.attributes[key]
+        elif self.strategy_wildcard_key:
+            key = ('loaderstrategy', (self.strategy_wildcard_key,))
+            if key in context.attributes:
+                cls = context.attributes[key]
+
+        if cls:
             try:
                 return self._strategies[cls]
             except KeyError:
                 return self.__init_strategy(cls)
-        else:
-            return self.strategy
+        return self.strategy
 
     def _get_strategy(self, cls):
         try:
@@ -494,6 +502,9 @@ class PropertyOption(MapperOption):
         while tokens:
             token = tokens.popleft()
             if isinstance(token, basestring):
+                # wildcard token
+                if token.endswith(':*'):
+                    return [(token,)], []
                 sub_tokens = token.split(".", 1)
                 token = sub_tokens[0]
                 tokens.extendleft(sub_tokens[1:])
diff --git a/lib/sqlalchemy/orm/properties.py b/lib/sqlalchemy/orm/properties.py
index cc06311f4..59c4cb3dc 100644
--- a/lib/sqlalchemy/orm/properties.py
+++ b/lib/sqlalchemy/orm/properties.py
@@ -185,6 +185,8 @@ class RelationshipProperty(StrategizedProperty):
     
     """
 
+    strategy_wildcard_key = 'relationship:*'
+
     def __init__(self, argument,
         secondary=None, primaryjoin=None,
         secondaryjoin=None, 
diff --git a/lib/sqlalchemy/orm/strategies.py b/lib/sqlalchemy/orm/strategies.py
index 1bdd18cde..5f4b182d0 100644
--- a/lib/sqlalchemy/orm/strategies.py
+++ b/lib/sqlalchemy/orm/strategies.py
@@ -1319,6 +1319,13 @@ class EagerLazyOption(StrategizedOption):
     def __init__(self, key, lazy=True, chained=False,
                     propagate_to_loaders=True
                     ):
+        if isinstance(key[0], basestring) and key[0] == '*':
+            if len(key) != 1:
+                raise sa_exc.ArgumentError(
+                        "Wildcard identifier '*' must "
+                        "be specified alone.")
+            key = ("relationship:*",)
+            propagate_to_loaders = False
         super(EagerLazyOption, self).__init__(key)
         self.lazy = lazy
         self.chained = self.lazy in (False, 'joined', 'subquery') and chained