Merge branch 'version-3.1' into oauth_as_package

Conflicts:
	requirements-test.txt
	rest_framework/compat.py
	tests/settings.py
	tox.ini

1 files changed, 254 insertions, 0 deletions

diff --git a/rest_framework/validators.py b/rest_framework/validators.py
new file mode 100644
index 00000000..7ca4e6a9
--- /dev/null
+++ b/rest_framework/validators.py
@@ -0,0 +1,254 @@
+"""
+We perform uniqueness checks explicitly on the serializer class, rather
+the using Django's `.full_clean()`.
+
+This gives us better separation of concerns, allows us to use single-step
+object creation, and makes it possible to switch between using the implicit
+`ModelSerializer` class and an equivelent explicit `Serializer` class.
+"""
+from django.utils.translation import ugettext_lazy as _
+from rest_framework.exceptions import ValidationError
+from rest_framework.utils.representation import smart_repr
+
+
+class UniqueValidator:
+    """
+    Validator that corresponds to `unique=True` on a model field.
+
+    Should be applied to an individual field on the serializer.
+    """
+    message = _('This field must be unique.')
+
+    def __init__(self, queryset, message=None):
+        self.queryset = queryset
+        self.serializer_field = None
+        self.message = message or self.message
+
+    def set_context(self, serializer_field):
+        """
+        This hook is called by the serializer instance,
+        prior to the validation call being made.
+        """
+        # Determine the underlying model field name. This may not be the
+        # same as the serializer field name if `source=<>` is set.
+        self.field_name = serializer_field.source_attrs[0]
+        # Determine the existing instance, if this is an update operation.
+        self.instance = getattr(serializer_field.parent, 'instance', None)
+
+    def filter_queryset(self, value, queryset):
+        """
+        Filter the queryset to all instances matching the given attribute.
+        """
+        filter_kwargs = {self.field_name: value}
+        return queryset.filter(**filter_kwargs)
+
+    def exclude_current_instance(self, queryset):
+        """
+        If an instance is being updated, then do not include
+        that instance itself as a uniqueness conflict.
+        """
+        if self.instance is not None:
+            return queryset.exclude(pk=self.instance.pk)
+        return queryset
+
+    def __call__(self, value):
+        queryset = self.queryset
+        queryset = self.filter_queryset(value, queryset)
+        queryset = self.exclude_current_instance(queryset)
+        if queryset.exists():
+            raise ValidationError(self.message)
+
+    def __repr__(self):
+        return '<%s(queryset=%s)>' % (
+            self.__class__.__name__,
+            smart_repr(self.queryset)
+        )
+
+
+class UniqueTogetherValidator:
+    """
+    Validator that corresponds to `unique_together = (...)` on a model class.
+
+    Should be applied to the serializer class, not to an individual field.
+    """
+    message = _('The fields {field_names} must make a unique set.')
+    missing_message = _('This field is required.')
+
+    def __init__(self, queryset, fields, message=None):
+        self.queryset = queryset
+        self.fields = fields
+        self.serializer_field = None
+        self.message = message or self.message
+
+    def set_context(self, serializer):
+        """
+        This hook is called by the serializer instance,
+        prior to the validation call being made.
+        """
+        # Determine the existing instance, if this is an update operation.
+        self.instance = getattr(serializer, 'instance', None)
+
+    def enforce_required_fields(self, attrs):
+        """
+        The `UniqueTogetherValidator` always forces an implied 'required'
+        state on the fields it applies to.
+        """
+        if self.instance is not None:
+            return
+
+        missing = dict([
+            (field_name, self.missing_message)
+            for field_name in self.fields
+            if field_name not in attrs
+        ])
+        if missing:
+            raise ValidationError(missing)
+
+    def filter_queryset(self, attrs, queryset):
+        """
+        Filter the queryset to all instances matching the given attributes.
+        """
+        # If this is an update, then any unprovided field should
+        # have it's value set based on the existing instance attribute.
+        if self.instance is not None:
+            for field_name in self.fields:
+                if field_name not in attrs:
+                    attrs[field_name] = getattr(self.instance, field_name)
+
+        # Determine the filter keyword arguments and filter the queryset.
+        filter_kwargs = dict([
+            (field_name, attrs[field_name])
+            for field_name in self.fields
+        ])
+        return queryset.filter(**filter_kwargs)
+
+    def exclude_current_instance(self, attrs, queryset):
+        """
+        If an instance is being updated, then do not include
+        that instance itself as a uniqueness conflict.
+        """
+        if self.instance is not None:
+            return queryset.exclude(pk=self.instance.pk)
+        return queryset
+
+    def __call__(self, attrs):
+        self.enforce_required_fields(attrs)
+        queryset = self.queryset
+        queryset = self.filter_queryset(attrs, queryset)
+        queryset = self.exclude_current_instance(attrs, queryset)
+        if queryset.exists():
+            field_names = ', '.join(self.fields)
+            raise ValidationError(self.message.format(field_names=field_names))
+
+    def __repr__(self):
+        return '<%s(queryset=%s, fields=%s)>' % (
+            self.__class__.__name__,
+            smart_repr(self.queryset),
+            smart_repr(self.fields)
+        )
+
+
+class BaseUniqueForValidator:
+    message = None
+    missing_message = _('This field is required.')
+
+    def __init__(self, queryset, field, date_field, message=None):
+        self.queryset = queryset
+        self.field = field
+        self.date_field = date_field
+        self.message = message or self.message
+
+    def set_context(self, serializer):
+        """
+        This hook is called by the serializer instance,
+        prior to the validation call being made.
+        """
+        # Determine the underlying model field names. These may not be the
+        # same as the serializer field names if `source=<>` is set.
+        self.field_name = serializer.fields[self.field].source_attrs[0]
+        self.date_field_name = serializer.fields[self.date_field].source_attrs[0]
+        # Determine the existing instance, if this is an update operation.
+        self.instance = getattr(serializer, 'instance', None)
+
+    def enforce_required_fields(self, attrs):
+        """
+        The `UniqueFor<Range>Validator` classes always force an implied
+        'required' state on the fields they are applied to.
+        """
+        missing = dict([
+            (field_name, self.missing_message)
+            for field_name in [self.field, self.date_field]
+            if field_name not in attrs
+        ])
+        if missing:
+            raise ValidationError(missing)
+
+    def filter_queryset(self, attrs, queryset):
+        raise NotImplementedError('`filter_queryset` must be implemented.')
+
+    def exclude_current_instance(self, attrs, queryset):
+        """
+        If an instance is being updated, then do not include
+        that instance itself as a uniqueness conflict.
+        """
+        if self.instance is not None:
+            return queryset.exclude(pk=self.instance.pk)
+        return queryset
+
+    def __call__(self, attrs):
+        self.enforce_required_fields(attrs)
+        queryset = self.queryset
+        queryset = self.filter_queryset(attrs, queryset)
+        queryset = self.exclude_current_instance(attrs, queryset)
+        if queryset.exists():
+            message = self.message.format(date_field=self.date_field)
+            raise ValidationError({self.field: message})
+
+    def __repr__(self):
+        return '<%s(queryset=%s, field=%s, date_field=%s)>' % (
+            self.__class__.__name__,
+            smart_repr(self.queryset),
+            smart_repr(self.field),
+            smart_repr(self.date_field)
+        )
+
+
+class UniqueForDateValidator(BaseUniqueForValidator):
+    message = _('This field must be unique for the "{date_field}" date.')
+
+    def filter_queryset(self, attrs, queryset):
+        value = attrs[self.field]
+        date = attrs[self.date_field]
+
+        filter_kwargs = {}
+        filter_kwargs[self.field_name] = value
+        filter_kwargs['%s__day' % self.date_field_name] = date.day
+        filter_kwargs['%s__month' % self.date_field_name] = date.month
+        filter_kwargs['%s__year' % self.date_field_name] = date.year
+        return queryset.filter(**filter_kwargs)
+
+
+class UniqueForMonthValidator(BaseUniqueForValidator):
+    message = _('This field must be unique for the "{date_field}" month.')
+
+    def filter_queryset(self, attrs, queryset):
+        value = attrs[self.field]
+        date = attrs[self.date_field]
+
+        filter_kwargs = {}
+        filter_kwargs[self.field_name] = value
+        filter_kwargs['%s__month' % self.date_field_name] = date.month
+        return queryset.filter(**filter_kwargs)
+
+
+class UniqueForYearValidator(BaseUniqueForValidator):
+    message = _('This field must be unique for the "{date_field}" year.')
+
+    def filter_queryset(self, attrs, queryset):
+        value = attrs[self.field]
+        date = attrs[self.date_field]
+
+        filter_kwargs = {}
+        filter_kwargs[self.field_name] = value
+        filter_kwargs['%s__year' % self.date_field_name] = date.year
+        return queryset.filter(**filter_kwargs)