Changeset 355

Timestamp:

07/07/08 14:55:41 (5 years ago)

Author:

ged

Message:

- Added support for viewonly relationships (OneToMany and OneToOne).

Location:

elixir/trunk

Files:

• CHANGES (modified) (1 diff)
• elixir/relationships.py (modified) (4 diffs)
• tests/test_o2m.py (modified) (2 diffs)

elixir/trunk/CHANGES

@@ -22 +22 @@
   any).
 - Added on_reconstitute event/method decorator. Only works with SA 0.5.
+- Added support for viewonly relationships (OneToMany and OneToOne).
 
 Changes:

elixir/trunk/elixir/relationships.py

@@ -413 +413 @@
 
         kwargs.update(self.get_prop_kwargs())
+
         self.property = relation(self.target, **kwargs)
         self.add_mapper_property(self.name, self.property)
@@ -451 +452 @@
 
     def is_inverse(self, other):
-        return other is not self and \
+        # viewonly relationships shouldn't match as inverse of anything (so
+        # that no backref is created -- which doesn't make sense in that case)
+        viewonly = self.kwargs.get('viewonly', False) or \
+                   other.kwargs.get('viewonly', False)
+        return not viewonly and \
+               other is not self and \
                self.match_type_of(other) and \
                self.entity == other.target and \
@@ -612 +618 @@
 
     def create_keys(self, pk):
+        # When using a viewonly relationship, you are on your own: Elixir
+        # doesn't check that a corresponding ManyToOne relationship exists.
+        if self.kwargs.get('viewonly', False):
+            return
+
         # make sure an inverse relationship exists
         if self.inverse is None:
@@ -637 +648 @@
             kwargs['remote_side'] = self.inverse.foreign_key
 
-        if self.inverse.primaryjoin_clauses:
-            kwargs['primaryjoin'] = and_(*self.inverse.primaryjoin_clauses)
+        # viewonly relationships do not have any inverse (and they provide 
+        # their primaryjoin argument manually anyway).
+        if not self.kwargs.get('viewonly', False):
+            if self.inverse.primaryjoin_clauses:
+                kwargs['primaryjoin'] = and_(*self.inverse.primaryjoin_clauses)
 
         kwargs.update(self.kwargs)

elixir/trunk/tests/test_o2m.py

@@ -4 +4 @@
 
 from elixir import *
+from sqlalchemy import and_
+from sqlalchemy.ext.orderinglist import ordering_list
 
 def setup():
@@ -105 +107 @@
         print root
 
+    def test_viewonly(self):
+        class User(Entity):
+            two_blurbs = OneToMany('Blurb', primaryjoin=lambda:
+                and_(Blurb.user_id == User.id, Blurb.position < 2),
+                viewonly=True
+            )
+            blurbs = OneToMany('Blurb',
+                               collection_class=ordering_list('position'),
+                               order_by='position')
+
+        class Blurb(Entity):
+            user = ManyToOne('User')
+            position = Field(Integer)
+            blurb = Field(Unicode(255))
+
+            def __init__(self, blurb, **kwargs):
+                super(Blurb, self).__init__(blurb=blurb, **kwargs)
+
+            def __repr__(self):
+                return 'Blurb(%r, %r)' % (self.position, self.blurb)
+
+        setup_all(True)
+
+        user = User(blurbs=[Blurb(u'zero'), Blurb(u'one'), Blurb(u'two')])
+
+        session.commit()
+        session.clear()
+
+        user = User.get(1)
+        assert len(user.two_blurbs) == 2
+        assert user.two_blurbs[0].blurb == 'zero'
+        assert user.two_blurbs[1].blurb == 'one'
+
     def test_has_many_syntax(self):
         class Person(Entity):