Merge pull request #64 from druids/AddUpdateOnlyChangedFieldsToTheSma…

…rtModelSaveHelpers

Added update_only_changed_fields to the save helpers

chamber/commands/__init__.py

@@ -38,7 +38,7 @@ def handle(self, *args, **kwargs):
 class BulkImportCSVCommand(ImportCSVCommandMixin, BulkCSVImporter, BaseCommand):
 
     def __init__(self, *args, **kwargs):
-        super(BulkImportCSVCommand, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
         self.bar = None
 
     def _pre_import_rows(self, row_count):

chamber/exceptions/__init__.py

@@ -1,7 +1,7 @@
 class PersistenceException(Exception):
 
     def __init__(self, message=None):
-        super(PersistenceException, self).__init__()
+        super().__init__()
         self.message = message
 
     def __str__(self):

chamber/forms/fields.py

@@ -8,10 +8,10 @@ def __init__(self, *args, **kwargs):
         self.step = kwargs.pop('step', 'any')
         self.min = kwargs.pop('min', None)
         self.max = kwargs.pop('max', None)
-        super(DecimalField, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def widget_attrs(self, widget):
-        attrs = super(DecimalField, self).widget_attrs(widget)
+        attrs = super().widget_attrs(widget)
         attrs['step'] = self.step
         if self.min is not None:
             attrs['min'] = self.min
@@ -23,7 +23,7 @@ def widget_attrs(self, widget):
 class PriceNumberInput(forms.NumberInput):
 
     def __init__(self, currency, *args, **kwargs):
-        super(PriceNumberInput, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
         self.placeholder = currency
 
 
@@ -35,4 +35,4 @@ def __init__(self, *args, **kwargs):
         currency = kwargs.pop('currency', ugettext('CZK'))
         if 'widget' not in kwargs:
             kwargs['widget'] = PriceNumberInput(currency)
-        super(PriceField, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)

chamber/importers/__init__.py

@@ -25,7 +25,7 @@ def simple_count(filename, encoding):
 class DummyOutputStream(io.StringIO):
 
     def write(self, *args, **kwargs):
-        super(DummyOutputStream, self).write(*args)
+        super().write(*args)
 
 
 class AbstractCSVImporter:

chamber/models/__init__.py

@@ -1,14 +1,10 @@
-import copy
-
 import collections
 
 from itertools import chain
 
-from django.core.exceptions import ValidationError
 from django.db import models, transaction
 from django.db.models.base import ModelBase
 from django.utils.translation import ugettext_lazy as _
-from django.utils.encoding import force_text
 
 from chamber.exceptions import PersistenceException
 from chamber.patch import Options
@@ -51,6 +47,10 @@ class UnknownSingleton:
     def __repr__(self):
         return 'unknown'
 
+    def __bool__(self):
+        return False
+
+
 Unknown = UnknownSingleton()
 
 
@@ -94,6 +94,10 @@ def initial_values(self):
     def current_values(self):
         raise NotImplementedError
 
+    @property
+    def changed_values(self):
+        return {k: value_change.current for k, value_change in self.diff.items()}
+
     @property
     def diff(self):
         d1 = self.initial_values
@@ -159,7 +163,7 @@ class DynamicChangedFields(ChangedFields):
 
     def __init__(self, instance):
         super().__init__(
-            self._get_unknown_dict(instance) if instance._state.adding else self._get_instance_dict(instance)
+            self._get_unknown_dict(instance) if instance.is_adding else self._get_instance_dict(instance)
         )
         self.instance = instance
 
@@ -247,12 +251,12 @@ def fast_distinct(self):
         """
         return self.model.objects.filter(pk__in=self.values_list('pk', flat=True))
 
-    def change_and_save(self, **chaned_fields):
+    def change_and_save(self, update_only_changed_fields=False, **chaned_fields):
         """
         Changes a given `changed_fields` on each object in the queryset, saves objects
         and returns the changed objects in the queryset.
         """
-        bulk_change_and_save(self, **chaned_fields)
+        bulk_change_and_save(self, update_only_changed_fields=update_only_changed_fields, **chaned_fields)
         return self.filter()
 
 
@@ -276,10 +280,20 @@ class SmartModel(AuditModel, metaclass=SmartModelBase):
     dispatchers = []
 
     def __init__(self, *args, **kwargs):
-        super(SmartModel, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
+        self.is_adding = True
+        self.is_changing = False
         self.changed_fields = DynamicChangedFields(self)
         self.post_save = Signal(self)
 
+    @classmethod
+    def from_db(cls, db, field_names, values):
+        new = super().from_db(db, field_names, values)
+        new.is_adding = False
+        new.is_changing = True
+        new.changed_fields = DynamicChangedFields(new)
+        return new
+
     @property
     def has_changed(self):
         return bool(self.changed_fields)
@@ -299,7 +313,7 @@ def full_clean(self, exclude=None, *args, **kwargs):
 
         if errors:
             raise ValidationError(errors)
-        super(SmartModel, self).full_clean(exclude=exclude, *args, **kwargs)
+        super().full_clean(exclude=exclude, *args, **kwargs)
 
     def _clean_save(self, *args, **kwargs):
         self._persistence_clean(*args, **kwargs)
@@ -339,9 +353,8 @@ def _pre_save(self, *args, **kwargs):
     def _call_pre_save(self, *args, **kwargs):
         self._pre_save(*args, **kwargs)
 
-    def _save(self, is_cleaned_pre_save=None, is_cleaned_post_save=None, force_insert=False, force_update=False,
-              using=None, update_fields=None, *args, **kwargs):
-
+    def _save(self, update_only_changed_fields=False, is_cleaned_pre_save=None, is_cleaned_post_save=None,
+              force_insert=False, force_update=False, using=None, update_fields=None, *args, **kwargs):
         is_cleaned_pre_save = (
             self._smart_meta.is_cleaned_pre_save if is_cleaned_pre_save is None else is_cleaned_pre_save
         )
@@ -351,21 +364,26 @@ def _save(self, is_cleaned_pre_save=None, is_cleaned_post_save=None, force_inser
 
         origin = self.__class__
 
-        change = not self._state.adding
         kwargs.update(self._get_save_extra_kwargs())
 
-        self._call_pre_save(change, self.changed_fields, *args, **kwargs)
+        self._call_pre_save(self.is_changing, self.changed_fields, *args, **kwargs)
         if is_cleaned_pre_save:
             self._clean_pre_save(*args, **kwargs)
-        dispatcher_pre_save.send(sender=origin, instance=self, change=change,
+        dispatcher_pre_save.send(sender=origin, instance=self, change=self.is_changing,
                                  changed_fields=self.changed_fields.get_static_changes(),
                                  *args, **kwargs)
-        super(SmartModel, self).save(force_insert=force_insert, force_update=force_update, using=using,
+        if not update_fields and update_only_changed_fields:
+            update_fields = list(self.changed_fields.keys()) + ['changed_at']
+            # remove primary key from updating fields
+            if self._meta.pk.name in update_fields:
+                update_fields.remove(self._meta.pk.name)
+        super().save(force_insert=force_insert, force_update=force_update, using=using,
                                      update_fields=update_fields)
-        self._call_post_save(change, self.changed_fields, *args, **kwargs)
+
+        self._call_post_save(self.is_changing, self.changed_fields, *args, **kwargs)
         if is_cleaned_post_save:
             self._clean_post_save(*args, **kwargs)
-        dispatcher_post_save.send(sender=origin, instance=self, change=change,
+        dispatcher_post_save.send(sender=origin, instance=self, change=self.is_changing,
                                   changed_fields=self.changed_fields.get_static_changes(),
                                   *args, **kwargs)
         self.post_save.send()
@@ -376,12 +394,17 @@ def _post_save(self, *args, **kwargs):
     def _call_post_save(self, *args, **kwargs):
         self._post_save(*args, **kwargs)
 
-    def save(self, *args, **kwargs):
+    def save_simple(self, *args, **kwargs):
+        super().save(*args, **kwargs)
+
+    def save(self, update_only_changed_fields=False, *args, **kwargs):
         if self._smart_meta.is_save_atomic:
             with transaction.atomic():
-                self._save(*args, **kwargs)
+                self._save(update_only_changed_fields=update_only_changed_fields, *args, **kwargs)
         else:
-            self._save(*args, **kwargs)
+            self._save(update_only_changed_fields=update_only_changed_fields, *args, **kwargs)
+        self.is_adding = False
+        self.is_changing = True
         self.changed_fields = DynamicChangedFields(self)
 
     def _pre_delete(self, *args, **kwargs):
@@ -400,7 +423,7 @@ def _delete(self, is_cleaned_pre_delete=None, is_cleaned_post_delete=None, *args
         if is_cleaned_pre_delete:
             self._clean_pre_delete(*args, **kwargs)
 
-        super(SmartModel, self).delete(*args, **kwargs)
+        super().delete(*args, **kwargs)
 
         self._post_delete(*args, **kwargs)
 
@@ -430,13 +453,14 @@ def change(self, **changed_fields):
         change(self, **changed_fields)
         return self
 
-    def change_and_save(self, **changed_fields):
+    def change_and_save(self, update_only_changed_fields=False, **changed_fields):
         """
         Changes a given `changed_fields` on this object, saves it and returns itself.
-        :param changed_fields: fields to change
+        :param update_only_changed_fields: only changed fields will be updated in the database.
+        :param changed_fields: fields to change.
         :return: self
         """
-        change_and_save(self, **changed_fields)
+        change_and_save(self, update_only_changed_fields=update_only_changed_fields, **changed_fields)
         return self
 
     class Meta:

chamber/models/dispatchers.py

@@ -57,7 +57,7 @@ def _validate_init_params(self):
 
     def __init__(self, handler, property_name, signal=None):
         self.property_name = property_name
-        super(PropertyDispatcher, self).__init__(handler, signal)
+        super().__init__(handler, signal)
 
     def _can_dispatch(self, instance, **kwargs):
         return getattr(instance, self.property_name)
@@ -78,16 +78,15 @@ class StateDispatcher(BaseDispatcher):
     """
 
     def _validate_init_params(self):
-        super(StateDispatcher, self)._validate_init_params()
+        super()._validate_init_params()
         if self.field_value not in {value for value, _ in self.enum.choices}:
             raise ImproperlyConfigured('Enum of FieldDispatcher does not contain {}.'.format(self.field_value))
 
     def __init__(self, handler, enum, field, field_value, signal=None):
         self.enum = enum
         self.field = field
         self.field_value = field_value
-
-        super(StateDispatcher, self).__init__(handler, signal=signal)
+        super().__init__(handler, signal=signal)
 
     def _can_dispatch(self, instance, change, changed_fields, *args, **kwargs):
         return (

chamber/models/fields.py

@@ -38,7 +38,7 @@ def __init__(self, *args, **kwargs):
             kwargs['validators'].append(MinValueValidator(self.min))
         if self.max is not None:
             kwargs['validators'].append(MaxValueValidator(self.max))
-        super(DecimalField, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def formfield(self, **kwargs):
         defaults = {
@@ -48,7 +48,7 @@ def formfield(self, **kwargs):
             'max': self.max,
         }
         defaults.update(kwargs)
-        return super(DecimalField, self).formfield(**defaults)
+        return super().formfield(**defaults)
 
 
 class RestrictedFileValidator:
@@ -106,7 +106,7 @@ class RestrictedFileFieldMixin:
     def __init__(self, *args, **kwargs):
         max_upload_size = kwargs.pop('max_upload_size', config.CHAMBER_MAX_FILE_UPLOAD_SIZE) * 1024 * 1024
         allowed_content_types = kwargs.pop('allowed_content_types', None)
-        super(RestrictedFileFieldMixin, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
         self.validators.append(RestrictedFileValidator(max_upload_size))
         if allowed_content_types:
             self.validators = tuple(self.validators) + (
@@ -120,7 +120,7 @@ def generate_filename(self, instance, filename):
         """
         from unidecode import unidecode
 
-        return super(RestrictedFileFieldMixin, self).generate_filename(instance, unidecode(force_text(filename)))
+        return super().generate_filename(instance, unidecode(force_text(filename)))
 
 
 class FileField(RestrictedFileFieldMixin, OriginFileField):
@@ -131,7 +131,7 @@ class ImageField(RestrictedFileFieldMixin, OriginImageField):
 
     def __init__(self, *args, **kwargs):
         allowed_content_types = kwargs.pop('allowed_content_types', config.CHAMBER_DEFAULT_IMAGE_ALLOWED_CONTENT_TYPES)
-        super(ImageField, self).__init__(allowed_content_types=allowed_content_types, *args, **kwargs)
+        super().__init__(allowed_content_types=allowed_content_types, *args, **kwargs)
 
 
 def generate_random_upload_path(instance, filename):
@@ -146,7 +146,7 @@ class PrevValuePositiveIntegerField(models.PositiveIntegerField):
 
     def __init__(self, *args, **kwargs):
         self.copy_field_name = kwargs.pop('copy_field_name', None)
-        super(PrevValuePositiveIntegerField, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def pre_save(self, model_instance, add):
         if add or hasattr(model_instance, 'changed_fields') and self.copy_field_name in model_instance.changed_fields:
@@ -155,7 +155,7 @@ def pre_save(self, model_instance, add):
                 getattr(model_instance, self.copy_field_name)
                 if add else model_instance.initial_values[self.copy_field_name]
             )
-        return super(PrevValuePositiveIntegerField, self).pre_save(model_instance, add)
+        return super().pre_save(model_instance, add)
 
 
 class SubchoicesPositiveIntegerField(models.PositiveIntegerField):
@@ -168,7 +168,7 @@ def __init__(self, *args, **kwargs):
         assert self.enum is None or isinstance(self.enum, SubstatesChoicesNumEnum)
         if self.enum:
             kwargs['choices'] = self.enum.choices
-        super(SubchoicesPositiveIntegerField, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def _get_subvalue(self, model_instance):
         return getattr(model_instance, self.subchoices_field_name)
@@ -177,7 +177,7 @@ def clean(self, value, model_instance):
         if self.enum and self._get_subvalue(model_instance) not in self.enum.categories:
             return None
         else:
-            return super(SubchoicesPositiveIntegerField, self).clean(value, model_instance)
+            return super().clean(value, model_instance)
 
     def _raise_error_if_value_should_be_empty(self, value, subvalue):
         if self.enum and subvalue not in self.enum.categories and value is not None:
@@ -207,10 +207,10 @@ def __init__(self, *args, **kwargs):
         assert self.enum is None or isinstance(self.enum, SequenceChoicesEnumMixin)
         if self.enum:
             kwargs['choices'] = self.enum.choices
-        super(EnumSequenceFieldMixin, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def validate(self, value, model_instance):
-        super(EnumSequenceFieldMixin, self).validate(value, model_instance)
+        super().validate(value, model_instance)
         if self.enum:
             prev_value = (not model_instance._state.adding and model_instance.initial_values[self.attname]) or None
             allowed_next_values = self.enum.get_allowed_next_states(prev_value, model_instance)
@@ -240,7 +240,7 @@ def __init__(self, *args, **kwargs):
             'humanized': lambda val, inst, field: price_humanized(val, inst, currency=field.currency)
         }
         default_kwargs.update(kwargs)
-        super(PriceField, self).__init__(*args, **default_kwargs)
+        super().__init__(*args, **default_kwargs)
 
     def formfield(self, **kwargs):
         default_kwargs = {
@@ -249,17 +249,17 @@ def formfield(self, **kwargs):
         }
         default_kwargs.update(kwargs)
 
-        return super(PriceField, self).formfield(**default_kwargs)
+        return super().formfield(**default_kwargs)
 
 
 class PositivePriceField(PriceField):
 
     def __init__(self, *args, **kwargs):
         kwargs['validators'] = kwargs.get('validators', [])
         kwargs['validators'].append(MinValueValidator(Decimal('0.00')))
-        super(PositivePriceField, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def deconstruct(self):
-        name, path, args, kwargs = super(PositivePriceField, self).deconstruct()
+        name, path, args, kwargs = super().deconstruct()
         del kwargs['validators']
         return name, path, args, kwargs