Some of the core design decisions were finalised by Jacob, Malcolm
(please scream if I have misunderstood or don't remember things
correctly) and me at DjangoCon.

Honza Král
E-Mail: Honza.K...@gmail.com
ICQ#:   107471613
Phone:  +420 606 678585

* The ValidationError class has moved from forms.utils to
django.core.exceptions now that it is used for more than just forms.
ErrorList has been kept in forms.utils

validators
==========

not yet implemented - talking about plans here

* New validators (replacements for many, but not all of the old validators)
have been put in ``django.core.validators``
* the new validator is a function like:

def validate_something( value, all_values={}, instance=None ):
  if i_dont_like( value ):
    raise ValidationError( 'I dont like %r' % value,
error_code=validators.SOME_CODE )

the error_code can be used later in Forms to look up custom error messages.

django.db.models.Model class
============================

 * validate_unique has been moved here from ModelForm

 * clean and validate methods were added, the idea is that any
__validation__ should never alter the data, that's why the top-level
function that can result in data change is clean() and not validate()

    * clean() calls clean() on individual fields and then calls
validate(), ValidationError with message_dict containing the errors is
raised when errors occur
    * validate() calls validate_unique() and is a hook to add custom
instance-wide validation (just raise ValidationError from it)

 * no validate_FIELD or clean_FIELD hooks on models
 * validate is run even if some errors occur on the fields' clean() methods

Model fields (django.db.models.fields)
======================================
 * clean and validate methods were added, see Model for function

Form Fields (django.forms.fields)
=================================

 * form fields haven't been changed yet, I will probably try and do
the same thinng the old patch did:

   * The to_python() method remains and a validate() method have been added.
   Fields have had their clean() methods split into to_python() and validate()
   methods.

  * clean() now calls to_python() then validate().

django.forms.forms.BaseForm class
=================================

 * no changes here either, so far. Will probably also try and do:

   * Form gets a new validate() method, which is meant to replace clean(), and
    full_clean() now looks for validate_<field> methods, which are meant to
    replace clean_<field> methods.  full_clean() also uses the Form.validate()
    instead of Form.clean() to set the cleaned_data.

    - The validate_<field> methods are passed the Field.clean()'ed value (yea
   for fixing #3896).

django.forms.models.BaseModelForm class
=======================================
 * save_instance has been split into two functions:
   * make_instance(form, instance, fields=None, exclude=None) which
return unsaved instance with populated fields
   * save_maked_instance(form, instance, fields=None, commit=True,
fail_message='saved') which saves the populated instance (and it's m2m
data)
  save_instance remains and calls the two new functions

 * in it's clean() method constructs the instance with make_instance,
then runs validation on it

 * the validate_unique method has been moved to Model

 * the form's save() method only calls save_maked_instance

 django.forms.models.BaseModelFormset class
 ===========================================

 * calls form.save() in save_new and save_existing

known Issues
=========================

 * InlineFormSet.save_as_new is broken

unknown Issues
==========================
 * I am fairly sure there are many since I only wrote minimal tests

I would appreciate any feedback on this, especially on:
 should we change the current Form validation? - split to_python and
validate, etc..
 how big an effort should we make to get all the validation to one
place - the validators (ie remove the logic from FormFields and just
have them call the validators where possible)
 testing - anybody willing to write tests and/or have a piece of code
that I broke, please contact me