Ticket #4620: 4620_all.diff
| File 4620_all.diff, 4.8 kB (added by PhiR, 9 months ago) |
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django/newforms/models.py
old new 278 278 # Fields ##################################################################### 279 279 280 280 class QuerySetIterator(object): 281 def __init__(self, queryset, empty_label, cache_choices): 282 self.queryset = queryset 283 self.empty_label = empty_label 284 self.cache_choices = cache_choices 281 def __init__(self, field): 282 self.field = field 283 self.queryset = field.queryset 285 284 286 285 def __iter__(self): 287 if self. empty_label is not None:288 yield (u"", self. empty_label)286 if self.field.empty_label is not None: 287 yield (u"", self.field.empty_label) 289 288 for obj in self.queryset: 290 yield (obj.pk, s mart_unicode(obj))289 yield (obj.pk, self.field.label_from_instance(obj)) 291 290 # Clear the QuerySet cache if required. 292 if not self. cache_choices:291 if not self.field.cache_choices: 293 292 self.queryset._result_cache = None 294 293 295 294 class ModelChoiceField(ChoiceField): … … 321 320 322 321 queryset = property(_get_queryset, _set_queryset) 323 322 323 # this method will be used to create object labels by the QuerySetIterator. 324 # Override it to customize the label. 325 def label_from_instance(self, obj): 326 return smart_unicode(obj) 327 324 328 def _get_choices(self): 325 329 # If self._choices is set, then somebody must have manually set 326 330 # the property self.choices. In this case, just return self._choices. … … 331 335 # been consumed. Note that we're instantiating a new QuerySetIterator 332 336 # *each* time _get_choices() is called (and, thus, each time 333 337 # self.choices is accessed) so that we can ensure the QuerySet has not 334 # been consumed. 335 return QuerySetIterator(self.queryset, self.empty_label,336 self.cache_choices)338 # been consumed. This construct might look complicated but it allows 339 # for lazy evaluation of the queryset. 340 return QuerySetIterator(self) 337 341 338 342 def _set_choices(self, value): 339 343 # This method is copied from ChoiceField._set_choices(). It's necessary -
tests/modeltests/model_forms/models.py
old new 645 645 ... 646 646 ValidationError: [u'Select a valid choice. That choice is not one of the available choices.'] 647 647 648 # check that we can safely iterate choices repeatedly 649 >>> gen_one = list(f.choices) 650 >>> gen_two = f.choices 651 >>> gen_one[2] 652 (2L, u"It's a test") 653 >>> list(gen_two) 654 [(u'', u'---------'), (1L, u'Entertainment'), (2L, u"It's a test"), (3L, u'Third')] 648 655 656 # check that we can override the label_from_instance method to print custom labels (#4620) 657 >>> f.queryset = Category.objects.all() 658 >>> f.label_from_instance = lambda obj: "category " + str(obj) 659 >>> list(f.choices) 660 [(u'', u'---------'), (1L, 'category Entertainment'), (2L, "category It's a test"), (3L, 'category Third'), (4L, 'category Fourth')] 661 649 662 # ModelMultipleChoiceField #################################################### 650 663 651 664 >>> f = ModelMultipleChoiceField(Category.objects.all()) … … 730 743 ... 731 744 ValidationError: [u'Select a valid choice. 4 is not one of the available choices.'] 732 745 746 >>> f.queryset = Category.objects.all() 747 >>> f.label_from_instance = lambda obj: "multicategory " + str(obj) 748 >>> list(f.choices) 749 [(1L, 'multicategory Entertainment'), (2L, "multicategory It's a test"), (3L, 'multicategory Third'), (4L, 'multicategory Fourth')] 733 750 734 751 # PhoneNumberField ############################################################ 735 752 -
docs/newforms.txt
old new 1517 1517 ~~~~~~~~~~~~~~~~~~~~ 1518 1518 1519 1519 Allows the selection of a single model object, suitable for 1520 representing a foreign key. 1520 representing a foreign key. A ``ModelChoiceField`` will use the 1521 ``__unicode__()`` method of the model to represent them, but this 1522 can be customized by overriding the ``label_from_instance`` method 1523 of the field itself (ie subclassing it). The method receives an object 1524 as an argument and must return a string to represent it. 1521 1525 1522 1526 ``ModelMultipleChoiceField`` 1523 1527 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1524 1528 1525 1529 Allows the selection of one or more model objects, suitable for 1526 representing a many-to-many relation. 1530 representing a many-to-many relation. As with ``ModelChoiceField``, 1531 you can use ``label_from_instance`` to customize the object labels. 1527 1532 1528 1533 1529 1534 Creating custom fields
