1 files changed, 92 insertions, 7 deletions
diff --git a/django/newforms/models.py b/django/newforms/models.py
index d99619c44a..a938b6350e 100644
--- a/django/newforms/models.py
+++ b/django/newforms/models.py
@@ -1,13 +1,98 @@
 """
-Helper functions for creating Forms from Django models and database field objects.
+Helper functions for creating Form classes from Django models
+and database field objects.
 """
 
-__all__ = ('form_for_model', 'form_for_fields')
+from forms import BaseForm, DeclarativeFieldsMetaclass, SortedDictFromList
 
-def form_for_model(model):
-    "Returns a Form instance for the given Django model class."
-    raise NotImplementedError
+__all__ = ('save_instance', 'form_for_model', 'form_for_instance', 'form_for_fields')
+
+def model_save(self, commit=True):
+    """
+    Creates and returns model instance according to self.clean_data.
+
+    This method is created for any form_for_model Form.
+    """
+    if self.errors:
+        raise ValueError("The %s could not be created because the data didn't validate." % self._model._meta.object_name)
+    return save_instance(self, self._model(), commit)
+
+def save_instance(form, instance, commit=True):
+    """
+    Saves bound Form ``form``'s clean_data into model instance ``instance``.
+
+    Assumes ``form`` has a field for every non-AutoField database field in
+    ``instance``. If commit=True, then the changes to ``instance`` will be
+    saved to the database. Returns ``instance``.
+    """
+    from django.db import models
+    opts = instance.__class__._meta
+    if form.errors:
+        raise ValueError("The %s could not be changed because the data didn't validate." % opts.object_name)
+    clean_data = form.clean_data
+    for f in opts.fields:
+        if isinstance(f, models.AutoField):
+            continue
+        setattr(instance, f.attname, clean_data[f.name])
+    if commit:
+        instance.save()
+        for f in opts.many_to_many:
+            setattr(instance, f.attname, clean_data[f.name])
+    # GOTCHA: If many-to-many data is given and commit=False, the many-to-many
+    # data will be lost. This happens because a many-to-many options cannot be
+    # set on an object until after it's saved. Maybe we should raise an
+    # exception in that case.
+    return instance
+
+def make_instance_save(instance):
+    "Returns the save() method for a form_for_instance Form."
+    def save(self, commit=True):
+        return save_instance(self, instance, commit)
+    return save
+
+def form_for_model(model, form=BaseForm, formfield_callback=lambda f: f.formfield()):
+    """
+    Returns a Form class for the given Django model class.
+
+    Provide ``form`` if you want to use a custom BaseForm subclass.
+
+    Provide ``formfield_callback`` if you want to define different logic for
+    determining the formfield for a given database field. It's a callable that
+    takes a database Field instance and returns a form Field instance.
+    """
+    opts = model._meta
+    field_list = []
+    for f in opts.fields + opts.many_to_many:
+        formfield = formfield_callback(f)
+        if formfield:
+            field_list.append((f.name, formfield))
+    fields = SortedDictFromList(field_list)
+    return type(opts.object_name + 'Form', (form,), {'base_fields': fields, '_model': model, 'save': model_save})
+
+def form_for_instance(instance, form=BaseForm, formfield_callback=lambda f, **kwargs: f.formfield(**kwargs)):
+    """
+    Returns a Form class for the given Django model instance.
+
+    Provide ``form`` if you want to use a custom BaseForm subclass.
+
+    Provide ``formfield_callback`` if you want to define different logic for
+    determining the formfield for a given database field. It's a callable that
+    takes a database Field instance, plus **kwargs, and returns a form Field
+    instance with the given kwargs (i.e. 'initial').
+    """
+    model = instance.__class__
+    opts = model._meta
+    field_list = []
+    for f in opts.fields + opts.many_to_many:
+        current_value = f.value_from_object(instance)
+        formfield = formfield_callback(f, initial=current_value)
+        if formfield:
+            field_list.append((f.name, formfield))
+    fields = SortedDictFromList(field_list)
+    return type(opts.object_name + 'InstanceForm', (form,),
+        {'base_fields': fields, '_model': model, 'save': make_instance_save(instance)})
 
 def form_for_fields(field_list):
-    "Returns a Form instance for the given list of Django database field instances."
-    raise NotImplementedError
+    "Returns a Form class for the given list of Django database field instances."
+    fields = SortedDictFromList([(f.name, f.formfield()) for f in field_list])
+    return type('FormForFields', (BaseForm,), {'base_fields': fields})