Merge lp:~therve/storm/reference-invalidated-state into lp:storm

[Thomas Herve]

[James Henstridge (jamesh)]

Looks good.

review: Approve

[Jamu Kakar (jkakar)]

[1]

+ def test_primary_key_reference(self):
+ """
+ When an object reference another one using its primary key, it
+ correctly checks for the invalidated state after the store has been
+ committed, detecting if the referenced object has been removed behind
+ its back.
+ """

s/object reference/object references/ please

[2]

Would you mind adding a docstring to get_remote, describing it's
behaviour, including mention of what happens when the remote object
disappears, please?

+1!

review: Approve

[lp:~therve/storm/reference-invalidated-state]

340. By Thomas Herve on 2009-11-25

Add a docstring to get_remote.

341. By Thomas Herve on 2009-11-25

Typo

=== modified file 'storm/references.py'
--- storm/references.py	2009-11-20 20:54:23 +0000
+++ storm/references.py	2009-11-25 16:43:13 +0000
@@ -21,7 +21,7 @@
 import weakref
 
 from storm.exceptions import WrongStoreError, NoStoreError, ClassInfoError
-from storm.store import Store, get_where_for_args
+from storm.store import Store, get_where_for_args, LostObjectError
 from storm.variables import LazyValue
 from storm.expr import (
     Select, Column, Exists, ComparableExpr, LeftJoin, Not, SQLRaw,
@@ -467,11 +467,23 @@
         self._r_to_l = {}
 
     def get_remote(self, local):
+        """Return the remote object for this relation, using the local cache.
+
+        If the object in the cache is invalidated, we validate it again to
+        check if it's still in the database.
+        """
         local_info = get_obj_info(local)
         try:
-            return local_info[self]["remote"]
+            obj = local_info[self]["remote"]
         except KeyError:
             return None
+        remote_info = get_obj_info(obj)
+        if remote_info.get("invalidated"):
+            try:
+                Store.of(obj)._validate_alive(remote_info)
+            except LostObjectError:
+                return None
+        return obj
 
     def get_where_for_remote(self, local):
         """Generate a column comparison expression for reference properties.

=== modified file 'tests/store/base.py'
--- tests/store/base.py	2009-11-20 20:25:35 +0000
+++ tests/store/base.py	2009-11-25 16:43:14 +0000
@@ -30,8 +30,7 @@
 from storm.properties import PropertyPublisherMeta, Decimal
 from storm.variables import PickleVariable
 from storm.expr import (
-    Asc, Desc, Select, Func, LeftJoin, SQL, Count, Sum, Avg, And, Or, Eq,
-    Lower)
+    Asc, Desc, Select, LeftJoin, SQL, Count, Sum, Avg, And, Or, Eq, Lower)
 from storm.variables import Variable, UnicodeVariable, IntVariable
 from storm.info import get_obj_info, ClassAlias
 from storm.exceptions import *
@@ -5009,6 +5008,24 @@
         obj_info = get_obj_info(foo)
         self.assertEquals(obj_info.variables[Foo.title].get_lazy(), AutoReload)
 
+    def test_primary_key_reference(self):
+        """
+        When an object references another one using its primary key, it
+        correctly checks for the invalidated state after the store has been
+        committed, detecting if the referenced object has been removed behind
+        its back.
+        """
+        class BarOnRemote(object):
+            __storm_table__ = "bar"
+            foo_id = Int(primary=True)
+            foo = Reference(foo_id, Foo.id, on_remote=True)
+        foo = self.store.get(Foo, 10)
+        bar = self.store.get(BarOnRemote, 10)
+        self.assertEqual(bar.foo, foo)
+        self.store.execute("DELETE FROM foo WHERE id = 10")
+        self.store.commit()
+        self.assertEqual(bar.foo, None)
+
     def test_invalidate_and_get_object(self):
         foo = self.store.get(Foo, 20)
         self.store.invalidate(foo)