Backwards-incompatible change -- Removed LazyDate helper class. To preserve existing functionality, query arguments can now be callable. Callable query arguments are evaluated with the query is evaluated.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4985 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/auth/models.py

@@ -98,8 +98,8 @@ class User(models.Model):
     is_staff = models.BooleanField(_('staff status'), default=False, help_text=_("Designates whether the user can log into this admin site."))
     is_active = models.BooleanField(_('active'), default=True, help_text=_("Designates whether this user can log into the Django admin. Unselect this instead of deleting accounts."))
     is_superuser = models.BooleanField(_('superuser status'), default=False, help_text=_("Designates that this user has all permissions without explicitly assigning them."))
-    last_login = models.DateTimeField(_('last login'), default=models.LazyDate())
-    date_joined = models.DateTimeField(_('date joined'), default=models.LazyDate())
+    last_login = models.DateTimeField(_('last login'), default=datetime.datetime.now)
+    date_joined = models.DateTimeField(_('date joined'), default=datetime.datetime.now)
     groups = models.ManyToManyField(Group, verbose_name=_('groups'), blank=True,
         help_text=_("In addition to the permissions manually assigned, this user will also get all permissions granted to each group he/she is in."))
     user_permissions = models.ManyToManyField(Permission, verbose_name=_('user permissions'), blank=True, filter_interface=models.HORIZONTAL)

django/db/models/__init__.py

@@ -27,32 +27,3 @@ def permalink(func):
         viewname = bits[0]
         return reverse(bits[0], None, *bits[1:3])
     return inner
-
-class LazyDate(object):
-    """
-    Use in limit_choices_to to compare the field to dates calculated at run time
-    instead of when the model is loaded.  For example::
-
-        ... limit_choices_to = {'date__gt' : models.LazyDate(days=-3)} ...
-
-    which will limit the choices to dates greater than three days ago.
-    """
-    def __init__(self, **kwargs):
-        self.delta = datetime.timedelta(**kwargs)
-
-    def __str__(self):
-        return str(self.__get_value__())
-
-    def __repr__(self):
-        return "<LazyDate: %s>" % self.delta
-
-    def __get_value__(self):
-        return (datetime.datetime.now() + self.delta).date()
-
-    def __getattr__(self, attr):
-        if attr == 'delta':
-            # To fix ticket #3377. Note that normal accesses to LazyDate.delta
-            # (after construction) will still work, because they don't go
-            # through __getattr__). This is mainly needed for unpickling.
-            raise AttributeError
-        return getattr(self.__get_value__(), attr)

django/db/models/query.py

@@ -826,7 +826,9 @@ def parse_lookup(kwarg_items, opts):
             # Interpret '__exact=None' as the sql '= NULL'; otherwise, reject
             # all uses of None as a query value.
             if lookup_type != 'exact':
-                raise ValueError, "Cannot use None as a query value"
+                raise ValueError, "Cannot use None as a query value"      
+        elif callable(value):
+            value = value()
 
         joins2, where2, params2 = lookup_inner(path, lookup_type, value, opts, opts.db_table, None)
         joins.update(joins2)

docs/model-api.txt

@@ -734,10 +734,10 @@ relationship should work. All are optional:
     ``limit_choices_to``     A dictionary of lookup arguments and values (see
                              the `Database API reference`_) that limit the
                              available admin choices for this object. Use this
-                             with ``models.LazyDate`` to limit choices of objects
-                             by date. For example::
+                             with functions from the Python ``datetime`` module 
+                             to limit choices of objects by date. For example::
 
-                                limit_choices_to = {'pub_date__lte': models.LazyDate()}
+                                limit_choices_to = {'pub_date__lte': datetime.now}
 
                              only allows the choice of related objects with a
                              ``pub_date`` before the current date/time to be