我们从Python开源项目中，提取了以下35个代码示例，用于说明如何使用django.db.models.fields.related.ForeignObjectRel()。
def is_valid_field(self, model, field): # Split with maximum splits of 1, so if passed xx__yy__zz, we get [xx, yy__zz] components = field.split(LOOKUP_SEP, 1) try: field = model._meta.get_field(components[0]) # Reverse lookup if isinstance(field, ForeignObjectRel): return self.is_valid_field(field.model, components[1]) if field.get_internal_type() in self.related_field_types and len(components) > 1: return self.is_valid_field(field.related_model, components[1]) return True except FieldDoesNotExist: return False
def is_valid_field(self, model, field): """ Return true if the field exists within the model (or in the related model specified using the Django ORM __ notation) """ components = field.split('__', 1) try: field, parent_model, direct, m2m = \ model._meta.get_field_by_name(components[0]) # reverse relation if isinstance(field, ForeignObjectRel): return self.is_valid_field(field.model, components[1]) # foreign key if field.rel and len(components) == 2: return self.is_valid_field(field.rel.to, components[1]) return True except FieldDoesNotExist: return False
def getCustomProperties(self): self.fields = {} self.relations = {} self.columns = [] self.meta = self.klass._meta for name in self.meta.get_all_field_names(): x = self.meta.get_field_by_name(name)[0] if isinstance(x, files.FileField): self.readonly_attrs.update([name]) if isinstance(x, ForeignObjectRel): continue if isinstance(x, models.ManyToManyField): self.relations[name] = x elif not isinstance(x, models.ForeignKey): self.fields[name] = x else: self.relations[name] = x parent_fields = [] for field in self.meta.parents.values(): parent_fields.append(field.attname) del self.relations[field.name] self.exclude_attrs.update(parent_fields) props = self.fields.keys() self.encodable_properties.update(props) self.decodable_properties.update(props) self.exclude_attrs.update(['_state'])
def select_on_queryset(self, queryset): """ This method runs either prefetch_related or select_related on the queryset to improve indexing speed of the relation. It decides which method to call based on the number of related objects: - single (eg ForeignKey, OneToOne), it runs select_related - multiple (eg ManyToMany, reverse ForeignKey) it runs prefetch_related """ try: field = self.get_field(queryset.model) except FieldDoesNotExist: return queryset if isinstance(field, RelatedField): if field.many_to_one or field.one_to_one: queryset = queryset.select_related(self.field_name) elif field.one_to_many or field.many_to_many: queryset = queryset.prefetch_related(self.field_name) elif isinstance(field, ForeignObjectRel): # Reverse relation if isinstance(field, OneToOneRel): # select_related for reverse OneToOneField queryset = queryset.select_related(self.field_name) else: # prefetch_related for anything else (reverse ForeignKey/ManyToManyField) queryset = queryset.prefetch_related(self.field_name) return queryset
def is_related_field(field): return isinstance(field, ForeignObjectRel)
def test_model_fields(self): f = Contact._meta.get_field("customer") self.assertIsInstance(f, CompositeForeignKey) l = Contact._meta.get_fields() self.assertIn("customer", [field.name for field in l]) f2 = Customer._meta.get_field("contacts") self.assertIsInstance(f2, ForeignObjectRel) l2 = Customer._meta.get_fields() self.assertIn("contacts", [field.name for field in l2]) self.assertIsNone(f.db_type(None))
def has_output(self): if (isinstance(self.field, ForeignObjectRel) and self.field.field.null or hasattr(self.field, 'rel') and self.field.null): extra = 1 else: extra = 0 return len(self.lookup_choices) + extra > 1
def choices(self, cl): from django.contrib.admin.views.main import EMPTY_CHANGELIST_VALUE yield { 'selected': self.lookup_val is None and not self.lookup_val_isnull, 'query_string': cl.get_query_string({}, [self.lookup_kwarg, self.lookup_kwarg_isnull]), 'display': _('All'), } for pk_val, val in self.lookup_choices: yield { 'selected': self.lookup_val == smart_text(pk_val), 'query_string': cl.get_query_string({ self.lookup_kwarg: pk_val, }, [self.lookup_kwarg_isnull]), 'display': val, } if (isinstance(self.field, ForeignObjectRel) and (self.field.field.null or isinstance(self.field.field, ManyToManyField)) or hasattr(self.field, 'rel') and (self.field.null or isinstance(self.field, ManyToManyField))): yield { 'selected': bool(self.lookup_val_isnull), 'query_string': cl.get_query_string({ self.lookup_kwarg_isnull: 'True', }, [self.lookup_kwarg]), 'display': EMPTY_CHANGELIST_VALUE, }
def _django_get_all_field_names(model): from itertools import chain from django.db.models import Manager from django.db.models.fields.related import ForeignObjectRel return list(set(chain.from_iterable( (field.name, field.attname) if hasattr(field, 'attname') else (field.name,) for field in model._meta.get_fields() if not isinstance(field, ForeignObjectRel) )))
def choices(self, cl): # #### MPTT ADDITION START try: # EMPTY_CHANGELIST_VALUE has been removed in django 1.9 from django.contrib.admin.views.main import EMPTY_CHANGELIST_VALUE except: EMPTY_CHANGELIST_VALUE = self.empty_value_display # #### MPTT ADDITION END yield { 'selected': self.lookup_val is None and not self.lookup_val_isnull, 'query_string': cl.get_query_string({}, [self.lookup_kwarg, self.lookup_kwarg_isnull]), 'display': _('All'), } for pk_val, val, padding_style in self.lookup_choices: yield { 'selected': self.lookup_val == smart_text(pk_val), 'query_string': cl.get_query_string({ self.lookup_kwarg: pk_val, }, [self.lookup_kwarg_isnull]), 'display': val, # #### MPTT ADDITION START 'padding_style': padding_style, # #### MPTT ADDITION END } if (isinstance(self.field, ForeignObjectRel) and (self.field.field.null or isinstance(self.field.field, ManyToManyField)) or hasattr(self.field, 'rel') and (self.field.null or isinstance(self.field, ManyToManyField))): yield { 'selected': bool(self.lookup_val_isnull), 'query_string': cl.get_query_string({ self.lookup_kwarg_isnull: 'True', }, [self.lookup_kwarg]), 'display': EMPTY_CHANGELIST_VALUE, }
def is_related_field(field): return isinstance(field,ForeignObjectRel)
def get_model_fields(self): """ Method to get all model fields for the content type associated with the forms specified content type :return: List of model field instances """ def is_valid_field(field): if isinstance(field, (models.AutoField, ForeignObjectRel, GenericRelation, GenericForeignKey)): return False else: return True return list(filter(is_valid_field, self.content_type.model_class()._meta.get_fields()))
