[soc2010/query-refactor] Improved the ListField implementation, and added an EmbeddedModelField.

git-svn-id: http://code.djangoproject.com/svn/django/branches/soc2010/query-refactor@13564 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 57 insertions, 2 deletions

diff --git a/django/db/models/__init__.py b/django/db/models/__init__.py
index 0736648a7b..6c0161a0e9 100644
--- a/django/db/models/__init__.py
+++ b/django/db/models/__init__.py
@@ -13,7 +13,7 @@ from django.db.models.fields.subclassing import SubfieldBase
 from django.db.models.fields.files import FileField, ImageField
 from django.db.models.fields.related import (ForeignKey, OneToOneField,
     ManyToManyField, ManyToOneRel, ManyToManyRel, OneToOneRel)
-from django.db.models.fields.structures import ListField
+from django.db.models.fields.structures import ListField, EmbeddedModel
 from django.db.models import signals
 
 # Admin stages.
diff --git a/django/db/models/fields/structures.py b/django/db/models/fields/structures.py
index 2d3822e932..b90164cc28 100644
--- a/django/db/models/fields/structures.py
+++ b/django/db/models/fields/structures.py
@@ -1,10 +1,15 @@
+from django.core.exceptions import ValidationError
+from django.db.models.loading import cache
 from django.db.models.fields import Field
+from django.db.models.fields.subclassing import SubfieldBase
 
 
 class ListField(Field):
+    __metaclass__ = SubfieldBase
+    
     def __init__(self, field_type):
         self.field_type = field_type
-        super(ListField, self).__init__()
+        super(ListField, self).__init__(default=[])
     
     def get_prep_lookup(self, lookup_type, value):
         return self.field_type.get_prep_lookup(lookup_type, value)
@@ -19,3 +24,53 @@ class ListField(Field):
         return self.field_type.get_db_prep_lookup(
             lookup_type, value, connection=connection, prepared=prepared
         )
+    
+    def to_python(self, value):
+        try:
+            value = iter(value)
+        except TypeError:
+            raise ValidationError("Value should be iterable")
+        return [
+            self.field_type.to_python(v)
+            for v in value
+        ]
+
+
+class EmbeddedModel(Field):
+    __metaclass__ = SubfieldBase
+    
+    def __init__(self, to):
+        self.to = to
+        super(EmbeddedModel, self).__init__()
+    
+    def get_db_prep_save(self, value, connection):
+        data = {}
+        if not isinstance(value, self.to):
+            raise ValidationError("Value must be an instance of %s, got %s "
+                "instead" % (self.to, value))
+        if type(value) is not self.to:
+            data["_cls"] = (value._meta.app_label, value._meta.object_name)
+        for field in value._meta.fields:
+            # If the field is a OneToOneField that makes the inheritance link,
+            # ignore it.
+            if field.rel and field.rel.parent_link:
+                continue
+            data[field.column] = field.get_db_prep_save(
+                getattr(value, field.name), connection=connection
+            )
+        return data
+    
+    def to_python(self, value):
+        if isinstance(value, self.to):
+            return value
+        try:
+            value = dict(value)
+        except TypeError:
+            raise ValidationError("Value should be a dict")
+        
+        if "_cls" in value:
+            cls = cache.get_model(*value.pop("_cls"))
+        else:
+            cls = self.to
+        
+        return cls(**value)