Ticket #4102: 4102-modified.patch

File 4102-modified.patch, 5.0 KB (added by SmileyChris, 8 years ago)

Latest version of the patch, reimplemented checking against the existing value after a discussion with Collin because otherwise user input like forms/etc is going to mark everything modified regardless

  • django/db/models/base.py

     
    102102    def __ne__(self, other):
    103103        return not self.__eq__(other)
    104104
     105    def __setattr__(self, name, value):
     106        if name not in self._modified_attrs:
     107            if not hasattr(self, name) or value != self.__dict__[name]:
     108                self._modified_attrs.append(name)
     109        self.__dict__[name] = value
     110
     111    def _reset_modified_attrs(self):
     112        self.__dict__['_modified_attrs'] = []
     113
    105114    def __init__(self, *args, **kwargs):
     115        self._reset_modified_attrs()
    106116        dispatcher.send(signal=signals.pre_init, sender=self.__class__, args=args, kwargs=kwargs)
    107117
    108118        # There is a rather weird disparity here; if kwargs, it's set, then args
    109         # overrides it. It should be one or the other; don't duplicate the work
     119        # overrides it. It should be one or the other; don't duplicate the work.
    110120        # The reason for the kwargs check is that standard iterator passes in by
    111         # args, and nstantiation for iteration is 33% faster.
     121        # args, and instantiation for iteration is 33% faster.
    112122        args_len = len(args)
    113123        if args_len > len(self._meta.fields):
    114124            # Daft, but matches old exception sans the err msg.
     
    207217    _prepare = classmethod(_prepare)
    208218
    209219    def save(self, raw=False):
     220        "Save model object to database, creating if doesn't exist, otherwise updating"
    210221        dispatcher.send(signal=signals.pre_save, sender=self.__class__, instance=self)
    211222
    212223        non_pks = [f for f in self._meta.fields if not f.primary_key]
     224        modified_attrs = self._modified_attrs
     225        non_pks = [f for f in non_pks if (f.name in modified_attrs or
     226                                          f.attname in modified_attrs)]
     227        self._reset_modified_attrs()
    213228        cursor = connection.cursor()
    214229
    215230        qn = connection.ops.quote_name
  • django/db/models/query.py

     
    204204                                                    index_start=0, max_depth=self._max_related_depth)
    205205                else:
    206206                    obj = self.model(*row[:index_end])
     207                    # Models keep a track of modified attrs to choose which
     208                    # fields to save. Since we're just pulling from the
     209                    # database, nothing has changed yet.
     210                    obj._reset_modified_attrs()
    207211                for i, k in enumerate(extra_select):
    208212                    setattr(obj, k[0], row[index_end+i])
    209213                yield obj
  • tests/modeltests/update_fields/models.py

     
     1"""
     2#. Save only modified fields on update
     3"""
     4from django.db import models
     5
     6class Article(models.Model):
     7    headline = models.CharField(maxlength=100, default='Default headline')
     8    body = models.TextField()
     9    pub_date = models.DateTimeField()
     10
     11    class Meta:
     12        ordering = ('pub_date','headline')
     13
     14    def __str__(self):
     15        return self.headline
     16
     17__test__ = {'API_TESTS':"""
     18# Create a couple of Articles.
     19>>> from datetime import datetime
     20>>> a = Article(headline='Article 1', body='Body 1', pub_date=datetime(2007, 5, 5))
     21>>> a.save()
     22
     23# Change headline and body on different instances, then save both to verify
     24# that each only updated the modified field.
     25>>> a1 = Article.objects.get(pk=a.id)
     26>>> a2 = Article.objects.get(pk=a.id)
     27>>> a1.headline = 'Changed article 1'
     28>>> a2.body = 'Changed body 1'
     29>>> a1.save()
     30>>> a2.save()
     31>>> a3 = Article.objects.get(pk=a.id)
     32>>> a3.headline
     33u'Changed article 1'
     34>>> a3.body
     35u'Changed body 1'
     36
     37# Fields entered at instantiation of a model which will already exists should be
     38# saved as well.
     39>>> a = Article(id=a.id, headline='Reset article 1', body='Reset body 1', pub_date=datetime(2007, 5, 5))
     40>>> a.save()
     41>>> a3 = Article.objects.get(pk=a.id)
     42>>> a3.headline
     43u'Reset article 1'
     44>>> a3.body
     45u'Reset body 1'
     46
     47# If the value doesn't change, it won't be marked as modified -- otherwise user
     48# input like forms/etc is going to mark everything modified regardless.
     49>>> a1 = Article.objects.get(pk=a.id)
     50>>> a2 = Article.objects.get(pk=a.id)
     51>>> a1.headline = 'Changed article 2'
     52>>> a2.headline = a2.headline
     53>>> a2.body = 'Changed body 2'
     54>>> a1.save()
     55>>> a2.save()
     56>>> a3 = Article.objects.get(pk=a.id)
     57>>> a3.headline
     58u'Changed article 2'
     59>>> a3.body
     60u'Changed body 2'
     61"""}
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