Index: django/db/models/base.py =================================================================== --- django/db/models/base.py (revision 4218) +++ django/db/models/base.py (working copy) @@ -90,6 +90,7 @@ def __init__(self, *args, **kwargs): dispatcher.send(signal=signals.pre_init, sender=self.__class__, args=args, kwargs=kwargs) + self._django_initializing = True for f in self._meta.fields: if isinstance(f.rel, ManyToOneRel): try: @@ -127,6 +128,8 @@ setattr(self, self._meta.fields[i].attname, arg) dispatcher.send(signal=signals.post_init, sender=self.__class__, instance=self) + del self._django_initializing + def add_to_class(cls, name, value): if name == 'Admin': assert type(value) == types.ClassType, "%r attribute of %s model must be a class, not a %s object" % (name, cls.__name__, type(value)) Index: django/db/models/fields/__init__.py =================================================================== --- django/db/models/fields/__init__.py (revision 4218) +++ django/db/models/fields/__init__.py (working copy) @@ -70,7 +70,7 @@ core=False, rel=None, default=NOT_PROVIDED, editable=True, prepopulate_from=None, unique_for_date=None, unique_for_month=None, unique_for_year=None, validator_list=None, choices=None, radio_admin=None, - help_text='', db_column=None): + help_text='', db_column=None, getter=None, setter=None): self.name = name self.verbose_name = verbose_name self.primary_key = primary_key @@ -86,6 +86,8 @@ self.radio_admin = radio_admin self.help_text = help_text self.db_column = db_column + self.getter = getter + self.setter = setter # Set db_index to True if the field has a relationship and doesn't explicitly set db_index. self.db_index = db_index @@ -139,7 +141,37 @@ cls._meta.add_field(self) if self.choices: setattr(cls, 'get_%s_display' % self.name, curry(cls._get_FIELD_display, field=self)) + if self.setter is not None or self.getter is not None: + self.create_property_on_class(cls) + def create_property_on_class(self, cls): + """create the property to support setters and getters""" + name = self.name + field_att = "_%s" % name + + if self.getter: + getter_name = self.getter + def get_func(self): + value = getattr(self, field_att) + return getattr(self, getter_name)(value) + else: + def get_func(self): + return getattr(self, field_att) + + if self.setter: + setter_name = self.setter + def set_func(self, value): + if hasattr(self, '_django_initializing'): + setattr(self, field_att, value) + else: + setattr(self, field_att, + getattr(self, setter_name)(value)) + else: + def set_func(self, value): + setattr(self, field_att, value) + + setattr(cls, name, property(get_func, set_func)) + def get_attname(self): return self.name Index: tests/modeltests/getters_setters/__init__.py =================================================================== Index: tests/modeltests/getters_setters/models.py =================================================================== --- tests/modeltests/getters_setters/models.py (revision 0) +++ tests/modeltests/getters_setters/models.py (revision 0) @@ -0,0 +1,55 @@ +""" +Test the 'getter' and 'setter' functionality on fields. + +This tests a field with a setter, a field with a getter, and a field +with both. Since the getter/setter implementation is at the Field +level, and I've verified that all Field objects pass through the code +that constructs these properties, I believe it would be redundent to +test all the Field Types individually. + +Doc note: Setters +""" + +from django.db import models + +class GetSet(models.Model): + has_getter = models.CharField(maxlength=20, getter='simple_getter') + has_setter = models.CharField(maxlength=20, setter='simple_setter') + has_both = models.CharField(maxlength=20, getter='simple_getter', + setter='updater') + updated_length_field = models.IntegerField(default=0) + + def simple_getter(self, value): + return value + "_getter" + def simple_setter(self, value): + return value + "_setter" + def updater(self, value): + self.updated_length_field = len(value) + return value + + +__test__ = {'API_TESTS':""" +>>> a = GetSet(has_getter='x', has_setter='y', has_both='z') +>>> a.has_getter +'x_getter' +>>> a.has_setter +'y' +>>> a.has_both +'z_getter' + +# Setter has not run yet + +>>> a.updated_length_field +0 +>>> a.has_both = 'abcd' +>>> a.updated_length_field +4 +>>> a.save() +>>> a_id = a.id +>>> del a +>>> a = GetSet.objects.get(id=a_id) +>>> a.updated_length_field +4 +"""} + + Index: docs/model-api.txt =================================================================== --- docs/model-api.txt (revision 4218) +++ docs/model-api.txt (working copy) @@ -548,6 +548,16 @@ processing using the object's ``AddManipulator`` or ``ChangeManipulator`` classes. Default is ``True``. +``getter`` +~~~~~~~~~~ + +A string indicating a method of the class to call when you try +to retrieve the value of the field. The method will be passed as its +only argument the current "underlying value" of the field (as received +from the database, object construction, or previous setting +operation), and the return value of that method is what the user +receives. + ``help_text`` ~~~~~~~~~~~~~ @@ -581,6 +591,17 @@ Don't use this for a field unless it's a ``ForeignKey`` or has ``choices`` set. +``setter`` +~~~~~~~~~~ + +A string indicating a method of the class to call when you try to set +the value of the field. The method will be passed as its only argument +the value the user is setting the field to, and the return value is +what will actually be set in the database. + +The setter will not be run when the object is created, either by +database retrieval or construction. + ``unique`` ~~~~~~~~~~