Run eager loaders on unexpire

Eager loaders, such as joined loading, SELECT IN loading, etc., when
configured on a mapper or via query options will now be invoked during
the refresh on an expired object; in the case of selectinload and
subqueryload, since the additional load is for a single object only,
the "immediateload" scheme is used in these cases which resembles the
single-parent query emitted by lazy loading.

Change-Id: I7ca2c77bff58dc21015d60093a88c387937376b2
Fixes: #1763

1 files changed, 12 insertions, 1 deletions

diff --git a/lib/sqlalchemy/orm/state.py b/lib/sqlalchemy/orm/state.py
index f6c06acc8..ead9bf2bb 100644
--- a/lib/sqlalchemy/orm/state.py
+++ b/lib/sqlalchemy/orm/state.py
@@ -595,12 +595,23 @@ class InstanceState(interfaces.InspectionAttrInfo):
         self.expired_attributes.update(
             [
                 impl.key
-                for impl in self.manager._scalar_loader_impls
+                for impl in self.manager._loader_impls
                 if impl.expire_missing or impl.key in dict_
             ]
         )
 
         if self.callables:
+            # the per state loader callables we can remove here are
+            # LoadDeferredColumns, which undefers a column at the instance
+            # level that is mapped with deferred, and LoadLazyAttribute,
+            # which lazy loads a relationship at the instance level that
+            # is mapped with "noload" or perhaps "immediateload".
+            # Before 1.4, only column-based
+            # attributes could be considered to be "expired", so here they
+            # were the only ones "unexpired", which means to make them deferred
+            # again.   For the moment, as of 1.4 we also apply the same
+            # treatment relationships now, that is, an instance level lazy
+            # loader is reset in the same way as a column loader.
             for k in self.expired_attributes.intersection(self.callables):
                 del self.callables[k]