- polymorphic loading, working very rudimentallyrow_proc_integration

running orm2010, the whole approach adds callcounts.
code is more complex, less reliable, pretty much a total
bust.

will try to see if create_row_processor can remain but
be called against either "result" or a context namespace
ahead of time, and if this somehow can be used to simplify
the need to call upon strategy lookup twice.

1 files changed, 49 insertions, 7 deletions

diff --git a/lib/sqlalchemy/orm/interfaces.py b/lib/sqlalchemy/orm/interfaces.py
index d12c20a2c..45ab9b48f 100644
--- a/lib/sqlalchemy/orm/interfaces.py
+++ b/lib/sqlalchemy/orm/interfaces.py
@@ -107,7 +107,9 @@ class MapperProperty(_MappedAttribute, InspectionAttr, util.MemoizedSlots):
         """
         return {}
 
-    def setup(self, context, entity, path, adapter, **kwargs):
+    def setup(
+            self, context, query_entity, path, mapper,
+            adapter, column_collection, populators, **kw):
         """Called by Query for the purposes of constructing a SQL statement.
 
         Each MapperProperty associated with the target mapper processes the
@@ -116,6 +118,17 @@ class MapperProperty(_MappedAttribute, InspectionAttr, util.MemoizedSlots):
 
         """
 
+    def setup_for_missing_attribute(
+            self, context, query_entity, path, mapper, populators, **kw):
+        """Setup a strategy for a Query where this property was not yet
+        included.
+
+        This function can do everything that setup() does, *except* attempt
+        to modify the SQL query; the method may be called after the query
+        has already been emitted and results are being received.
+
+        """
+
     def cascade_iterator(self, type_, state, visited_instances=None,
                          halt_on=None):
         """Iterate through instances related to the given instance for
@@ -481,13 +494,31 @@ class StrategizedProperty(MapperProperty):
     def _get_strategy_by_cls(self, cls):
         return self._get_strategy(cls._strategy_keys[0])
 
-    def setup(self, context, entity, path, adapter, **kwargs):
-        loader = self._get_context_loader(context, path)
-        if loader and loader.strategy:
-            strat = self._get_strategy(loader.strategy)
+    def setup(
+            self, context, query_entity, path, mapper,
+            adapter, column_collection, populators, **kw):
+
+        loadopt = self._get_context_loader(context, path)
+        if loadopt and loadopt.strategy:
+            strat = self._get_strategy(loadopt.strategy)
         else:
             strat = self.strategy
-        strat.setup_query(context, entity, path, loader, adapter, **kwargs)
+
+        strat.setup_query(
+            context, query_entity, path, mapper,
+            adapter, column_collection, populators, loadopt, **kw)
+
+    def setup_for_missing_attribute(
+            self, context, query_entity, path, mapper,
+            populators, **kw):
+
+        loadopt = self._get_context_loader(context, path)
+        if loadopt and loadopt.strategy:
+            strat = self._get_strategy(loadopt.strategy)
+        else:
+            strat = self.strategy
+        strat.setup_for_missing_attribute(
+            context, query_entity, path, mapper, populators, loadopt, **kw)
 
     def do_init(self):
         self._strategies = {}
@@ -585,7 +616,9 @@ class LoaderStrategy(object):
     def init_class_attribute(self, mapper):
         pass
 
-    def setup_query(self, context, entity, path, loadopt, adapter, **kwargs):
+    def setup_query(
+            self, context, query_entity, path, mapper,
+            adapter, column_collection, populators, loadopt, **kw):
         """Establish column and other state for a given QueryContext.
 
         This method fulfills the contract specified by MapperProperty.setup().
@@ -595,5 +628,14 @@ class LoaderStrategy(object):
 
         """
 
+    def setup_for_missing_attribute(
+            self, context, query_entity, path, mapper,
+            populators, loadopt, **kw):
+        """Establish loader behavior for an attribute that's not accommodated
+        by the query.
+
+        This is used for polymorphic loading when a subclass load is detected.
+        """
+
     def __str__(self):
         return str(self.parent_property)