diff options
Diffstat (limited to 'rest_framework/relations.py')
| -rw-r--r-- | rest_framework/relations.py | 566 |
1 files changed, 68 insertions, 498 deletions
diff --git a/rest_framework/relations.py b/rest_framework/relations.py index 1acbdce2..661a1249 100644 --- a/rest_framework/relations.py +++ b/rest_framework/relations.py @@ -1,461 +1,80 @@ -""" -Serializer fields that deal with relationships. - -These fields allow you to specify the style that should be used to represent -model relationships, including hyperlinks, primary keys, or slugs. -""" -from __future__ import unicode_literals -from django.core.exceptions import ObjectDoesNotExist, ValidationError -from django.core.urlresolvers import resolve, get_script_prefix, NoReverseMatch -from django import forms -from django.db.models.fields import BLANK_CHOICE_DASH -from django.forms import widgets -from django.forms.models import ModelChoiceIterator -from django.utils.translation import ugettext_lazy as _ -from rest_framework.fields import Field, WritableField, get_component, is_simple_callable +from rest_framework.fields import Field from rest_framework.reverse import reverse +from django.core.exceptions import ObjectDoesNotExist +from django.core.urlresolvers import resolve, get_script_prefix, NoReverseMatch from rest_framework.compat import urlparse -from rest_framework.compat import smart_text -import warnings - - -# Relational fields - -# Not actually Writable, but subclasses may need to be. -class RelatedField(WritableField): - """ - Base class for related model fields. - - This represents a relationship using the unicode representation of the target. - """ - widget = widgets.Select - many_widget = widgets.SelectMultiple - form_field_class = forms.ChoiceField - many_form_field_class = forms.MultipleChoiceField - null_values = (None, '', 'None') - cache_choices = False - empty_label = None - read_only = True - many = False - def __init__(self, *args, **kwargs): - queryset = kwargs.pop('queryset', None) - self.many = kwargs.pop('many', self.many) - if self.many: - self.widget = self.many_widget - self.form_field_class = self.many_form_field_class +def get_default_queryset(serializer_class, field_name): + manager = getattr(serializer_class.opts.model, field_name) + if hasattr(manager, 'related'): + # Forward relationships + return manager.related.model._default_manager.all() + # Reverse relationships + return manager.field.rel.to._default_manager.all() - kwargs['read_only'] = kwargs.pop('read_only', self.read_only) - super(RelatedField, self).__init__(*args, **kwargs) - if not self.required: - # Accessed in ModelChoiceIterator django/forms/models.py:1034 - # If set adds empty choice. - self.empty_label = BLANK_CHOICE_DASH[0][1] +class RelatedField(Field): + def __init__(self, **kwargs): + self.queryset = kwargs.pop('queryset', None) + self.many = kwargs.pop('many', False) + super(RelatedField, self).__init__(**kwargs) - self.queryset = queryset - - def initialize(self, parent, field_name): - super(RelatedField, self).initialize(parent, field_name) + def bind(self, field_name, parent, root): + super(RelatedField, self).bind(field_name, parent, root) if self.queryset is None and not self.read_only: - manager = getattr(self.parent.opts.model, self.source or field_name) - if hasattr(manager, 'related'): # Forward - self.queryset = manager.related.model._default_manager.all() - else: # Reverse - self.queryset = manager.field.rel.to._default_manager.all() - - # We need this stuff to make form choices work... - - def prepare_value(self, obj): - return self.to_native(obj) - - def label_from_instance(self, obj): - """ - Return a readable representation for use with eg. select widgets. - """ - desc = smart_text(obj) - ident = smart_text(self.to_native(obj)) - if desc == ident: - return desc - return "%s - %s" % (desc, ident) - - def _get_queryset(self): - return self._queryset - - def _set_queryset(self, queryset): - self._queryset = queryset - self.widget.choices = self.choices - - queryset = property(_get_queryset, _set_queryset) - - def _get_choices(self): - # If self._choices is set, then somebody must have manually set - # the property self.choices. In this case, just return self._choices. - if hasattr(self, '_choices'): - return self._choices - - # Otherwise, execute the QuerySet in self.queryset to determine the - # choices dynamically. Return a fresh ModelChoiceIterator that has not been - # consumed. Note that we're instantiating a new ModelChoiceIterator *each* - # time _get_choices() is called (and, thus, each time self.choices is - # accessed) so that we can ensure the QuerySet has not been consumed. This - # construct might look complicated but it allows for lazy evaluation of - # the queryset. - return ModelChoiceIterator(self) - - def _set_choices(self, value): - # Setting choices also sets the choices on the widget. - # choices can be any iterable, but we call list() on it because - # it will be consumed more than once. - self._choices = self.widget.choices = list(value) - - choices = property(_get_choices, _set_choices) - - # Default value handling - - def get_default_value(self): - default = super(RelatedField, self).get_default_value() - if self.many and default is None: - return [] - return default - - # Regular serializer stuff... - - def field_to_native(self, obj, field_name): - try: - if self.source == '*': - return self.to_native(obj) - - source = self.source or field_name - value = obj - - for component in source.split('.'): - if value is None: - break - value = get_component(value, component) - except ObjectDoesNotExist: - return None + self.queryset = get_default_queryset(parent, self.source) - if value is None: - return None - - if self.many: - if is_simple_callable(getattr(value, 'all', None)): - return [self.to_native(item) for item in value.all()] - else: - # Also support non-queryset iterables. - # This allows us to also support plain lists of related items. - return [self.to_native(item) for item in value] - return self.to_native(value) - - def field_from_native(self, data, files, field_name, into): - if self.read_only: - return - - try: - if self.many: - try: - # Form data - value = data.getlist(field_name) - if value == [''] or value == []: - raise KeyError - except AttributeError: - # Non-form data - value = data[field_name] - else: - value = data[field_name] - except KeyError: - if self.partial: - return - value = self.get_default_value() - - if value in self.null_values: - if self.required: - raise ValidationError(self.error_messages['required']) - into[(self.source or field_name)] = None - elif self.many: - into[(self.source or field_name)] = [self.from_native(item) for item in value] - else: - into[(self.source or field_name)] = self.from_native(value) - - -# PrimaryKey relationships class PrimaryKeyRelatedField(RelatedField): - """ - Represents a relationship as a pk value. - """ - read_only = False - - default_error_messages = { - 'does_not_exist': _("Invalid pk '%s' - object does not exist."), - 'incorrect_type': _('Incorrect type. Expected pk value, received %s.'), + MESSAGES = { + 'required': 'This field is required.', + 'does_not_exist': "Invalid pk '{pk_value}' - object does not exist.", + 'incorrect_type': 'Incorrect type. Expected pk value, received {data_type}.', } - # TODO: Remove these field hacks... - def prepare_value(self, obj): - return self.to_native(obj.pk) - - def label_from_instance(self, obj): - """ - Return a readable representation for use with eg. select widgets. - """ - desc = smart_text(obj) - ident = smart_text(self.to_native(obj.pk)) - if desc == ident: - return desc - return "%s - %s" % (desc, ident) - - # TODO: Possibly change this to just take `obj`, through prob less performant - def to_native(self, pk): - return pk - def from_native(self, data): - if self.queryset is None: - raise Exception('Writable related fields must include a `queryset` argument') - try: return self.queryset.get(pk=data) except ObjectDoesNotExist: - msg = self.error_messages['does_not_exist'] % smart_text(data) - raise ValidationError(msg) + self.fail('does_not_exist', pk_value=data) except (TypeError, ValueError): - received = type(data).__name__ - msg = self.error_messages['incorrect_type'] % received - raise ValidationError(msg) - - def field_to_native(self, obj, field_name): - if self.many: - # To-many relationship - - queryset = None - if not self.source: - # Prefer obj.serializable_value for performance reasons - try: - queryset = obj.serializable_value(field_name) - except AttributeError: - pass - if queryset is None: - # RelatedManager (reverse relationship) - source = self.source or field_name - queryset = obj - for component in source.split('.'): - if queryset is None: - return [] - queryset = get_component(queryset, component) - - # Forward relationship - if is_simple_callable(getattr(queryset, 'all', None)): - return [self.to_native(item.pk) for item in queryset.all()] - else: - # Also support non-queryset iterables. - # This allows us to also support plain lists of related items. - return [self.to_native(item.pk) for item in queryset] - - # To-one relationship - try: - # Prefer obj.serializable_value for performance reasons - pk = obj.serializable_value(self.source or field_name) - except AttributeError: - # RelatedObject (reverse relationship) - try: - pk = getattr(obj, self.source or field_name).pk - except (ObjectDoesNotExist, AttributeError): - return None - - # Forward relationship - return self.to_native(pk) + self.fail('incorrect_type', data_type=type(data).__name__) -# Slug relationships - -class SlugRelatedField(RelatedField): - """ - Represents a relationship using a unique field on the target. - """ - read_only = False - - default_error_messages = { - 'does_not_exist': _("Object with %s=%s does not exist."), - 'invalid': _('Invalid value.'), - } - - def __init__(self, *args, **kwargs): - self.slug_field = kwargs.pop('slug_field', None) - assert self.slug_field, 'slug_field is required' - super(SlugRelatedField, self).__init__(*args, **kwargs) - - def to_native(self, obj): - return getattr(obj, self.slug_field) - - def from_native(self, data): - if self.queryset is None: - raise Exception('Writable related fields must include a `queryset` argument') - - try: - return self.queryset.get(**{self.slug_field: data}) - except ObjectDoesNotExist: - raise ValidationError(self.error_messages['does_not_exist'] % - (self.slug_field, smart_text(data))) - except (TypeError, ValueError): - msg = self.error_messages['invalid'] - raise ValidationError(msg) - - -# Hyperlinked relationships - class HyperlinkedRelatedField(RelatedField): - """ - Represents a relationship using hyperlinking. - """ - read_only = False lookup_field = 'pk' - default_error_messages = { - 'no_match': _('Invalid hyperlink - No URL match'), - 'incorrect_match': _('Invalid hyperlink - Incorrect URL match'), - 'configuration_error': _('Invalid hyperlink due to configuration error'), - 'does_not_exist': _("Invalid hyperlink - object does not exist."), - 'incorrect_type': _('Incorrect type. Expected url string, received %s.'), + MESSAGES = { + 'required': 'This field is required.', + 'no_match': 'Invalid hyperlink - No URL match', + 'incorrect_match': 'Invalid hyperlink - Incorrect URL match.', + 'does_not_exist': "Invalid hyperlink - Object does not exist.", + 'incorrect_type': 'Incorrect type. Expected URL string, received {data_type}.', } - # These are all deprecated - pk_url_kwarg = 'pk' - slug_field = 'slug' - slug_url_kwarg = None # Defaults to same as `slug_field` unless overridden - - def __init__(self, *args, **kwargs): - try: - self.view_name = kwargs.pop('view_name') - except KeyError: - raise ValueError("Hyperlinked field requires 'view_name' kwarg") - + def __init__(self, **kwargs): + self.view_name = kwargs.pop('view_name') self.lookup_field = kwargs.pop('lookup_field', self.lookup_field) - self.format = kwargs.pop('format', None) - - # These are deprecated - if 'pk_url_kwarg' in kwargs: - msg = 'pk_url_kwarg is deprecated. Use lookup_field instead.' - warnings.warn(msg, DeprecationWarning, stacklevel=2) - if 'slug_url_kwarg' in kwargs: - msg = 'slug_url_kwarg is deprecated. Use lookup_field instead.' - warnings.warn(msg, DeprecationWarning, stacklevel=2) - if 'slug_field' in kwargs: - msg = 'slug_field is deprecated. Use lookup_field instead.' - warnings.warn(msg, DeprecationWarning, stacklevel=2) - - self.pk_url_kwarg = kwargs.pop('pk_url_kwarg', self.pk_url_kwarg) - self.slug_field = kwargs.pop('slug_field', self.slug_field) - default_slug_kwarg = self.slug_url_kwarg or self.slug_field - self.slug_url_kwarg = kwargs.pop('slug_url_kwarg', default_slug_kwarg) - - super(HyperlinkedRelatedField, self).__init__(*args, **kwargs) + self.lookup_url_kwarg = kwargs.pop('lookup_url_kwarg', self.lookup_field) + super(HyperlinkedRelatedField, self).__init__(**kwargs) - def get_url(self, obj, view_name, request, format): - """ - Given an object, return the URL that hyperlinks to the object. - - May raise a `NoReverseMatch` if the `view_name` and `lookup_field` - attributes are not configured to correctly match the URL conf. - """ - lookup_field = getattr(obj, self.lookup_field) - kwargs = {self.lookup_field: lookup_field} - try: - return reverse(view_name, kwargs=kwargs, request=request, format=format) - except NoReverseMatch: - pass - - if self.pk_url_kwarg != 'pk': - # Only try pk if it has been explicitly set. - # Otherwise, the default `lookup_field = 'pk'` has us covered. - pk = obj.pk - kwargs = {self.pk_url_kwarg: pk} - try: - return reverse(view_name, kwargs=kwargs, request=request, format=format) - except NoReverseMatch: - pass - - slug = getattr(obj, self.slug_field, None) - if slug is not None: - # Only try slug if it corresponds to an attribute on the object. - kwargs = {self.slug_url_kwarg: slug} - try: - ret = reverse(view_name, kwargs=kwargs, request=request, format=format) - if self.slug_field == 'slug' and self.slug_url_kwarg == 'slug': - # If the lookup succeeds using the default slug params, - # then `slug_field` is being used implicitly, and we - # we need to warn about the pending deprecation. - msg = 'Implicit slug field hyperlinked fields are deprecated.' \ - 'You should set `lookup_field=slug` on the HyperlinkedRelatedField.' - warnings.warn(msg, DeprecationWarning, stacklevel=2) - return ret - except NoReverseMatch: - pass - - raise NoReverseMatch() - - def get_object(self, queryset, view_name, view_args, view_kwargs): + def get_object(self, view_name, view_args, view_kwargs): """ Return the object corresponding to a matched URL. - Takes the matched URL conf arguments, and the queryset, and should - return an object instance, or raise an `ObjectDoesNotExist` exception. + Takes the matched URL conf arguments, and should return an + object instance, or raise an `ObjectDoesNotExist` exception. """ - lookup = view_kwargs.get(self.lookup_field, None) - pk = view_kwargs.get(self.pk_url_kwarg, None) - slug = view_kwargs.get(self.slug_url_kwarg, None) - - if lookup is not None: - filter_kwargs = {self.lookup_field: lookup} - elif pk is not None: - filter_kwargs = {'pk': pk} - elif slug is not None: - filter_kwargs = {self.slug_field: slug} - else: - raise ObjectDoesNotExist() - - return queryset.get(**filter_kwargs) - - def to_native(self, obj): - view_name = self.view_name - request = self.context.get('request', None) - format = self.format or self.context.get('format', None) - - assert request is not None, ( - "`HyperlinkedRelatedField` requires the request in the serializer " - "context. Add `context={'request': request}` when instantiating " - "the serializer." - ) - - # If the object has not yet been saved then we cannot hyperlink to it. - if getattr(obj, 'pk', None) is None: - return - - # Return the hyperlink, or error if incorrectly configured. - try: - return self.get_url(obj, view_name, request, format) - except NoReverseMatch: - msg = ( - 'Could not resolve URL for hyperlinked relationship using ' - 'view name "%s". You may have failed to include the related ' - 'model in your API, or incorrectly configured the ' - '`lookup_field` attribute on this field.' - ) - raise Exception(msg % view_name) + lookup_value = view_kwargs[self.lookup_url_kwarg] + lookup_kwargs = {self.lookup_field: lookup_value} + return self.queryset.get(**lookup_kwargs) def from_native(self, value): - # Convert URL -> model instance pk - # TODO: Use values_list - queryset = self.queryset - if queryset is None: - raise Exception('Writable related fields must include a `queryset` argument') - try: http_prefix = value.startswith(('http:', 'https:')) except AttributeError: - msg = self.error_messages['incorrect_type'] - raise ValidationError(msg % type(value).__name__) + self.fail('incorrect_type', data_type=type(value).__name__) if http_prefix: # If needed convert absolute URLs to relative path @@ -467,63 +86,33 @@ class HyperlinkedRelatedField(RelatedField): try: match = resolve(value) except Exception: - raise ValidationError(self.error_messages['no_match']) + self.fail('no_match') if match.view_name != self.view_name: - raise ValidationError(self.error_messages['incorrect_match']) + self.fail('incorrect_match') try: - return self.get_object(queryset, match.view_name, - match.args, match.kwargs) + return self.get_object(match.view_name, match.args, match.kwargs) except (ObjectDoesNotExist, TypeError, ValueError): - raise ValidationError(self.error_messages['does_not_exist']) + self.fail('does_not_exist') -class HyperlinkedIdentityField(Field): - """ - Represents the instance, or a property on the instance, using hyperlinking. - """ +class HyperlinkedIdentityField(RelatedField): lookup_field = 'pk' - read_only = True - # These are all deprecated - pk_url_kwarg = 'pk' - slug_field = 'slug' - slug_url_kwarg = None # Defaults to same as `slug_field` unless overridden + def __init__(self, **kwargs): + kwargs['read_only'] = True + self.view_name = kwargs.pop('view_name') + self.lookup_field = kwargs.pop('lookup_field', self.lookup_field) + self.lookup_url_kwarg = kwargs.pop('lookup_url_kwarg', self.lookup_field) + super(HyperlinkedIdentityField, self).__init__(**kwargs) - def __init__(self, *args, **kwargs): - try: - self.view_name = kwargs.pop('view_name') - except KeyError: - msg = "HyperlinkedIdentityField requires 'view_name' argument" - raise ValueError(msg) - - self.format = kwargs.pop('format', None) - lookup_field = kwargs.pop('lookup_field', None) - self.lookup_field = lookup_field or self.lookup_field - - # These are deprecated - if 'pk_url_kwarg' in kwargs: - msg = 'pk_url_kwarg is deprecated. Use lookup_field instead.' - warnings.warn(msg, DeprecationWarning, stacklevel=2) - if 'slug_url_kwarg' in kwargs: - msg = 'slug_url_kwarg is deprecated. Use lookup_field instead.' - warnings.warn(msg, DeprecationWarning, stacklevel=2) - if 'slug_field' in kwargs: - msg = 'slug_field is deprecated. Use lookup_field instead.' - warnings.warn(msg, DeprecationWarning, stacklevel=2) - - self.slug_field = kwargs.pop('slug_field', self.slug_field) - default_slug_kwarg = self.slug_url_kwarg or self.slug_field - self.pk_url_kwarg = kwargs.pop('pk_url_kwarg', self.pk_url_kwarg) - self.slug_url_kwarg = kwargs.pop('slug_url_kwarg', default_slug_kwarg) - - super(HyperlinkedIdentityField, self).__init__(*args, **kwargs) - - def field_to_native(self, obj, field_name): + def get_attribute(self, instance): + return instance + + def to_primative(self, value): request = self.context.get('request', None) format = self.context.get('format', None) - view_name = self.view_name assert request is not None, ( "`HyperlinkedIdentityField` requires the request in the serializer" @@ -545,7 +134,7 @@ class HyperlinkedIdentityField(Field): # Return the hyperlink, or error if incorrectly configured. try: - return self.get_url(obj, view_name, request, format) + return self.get_url(value, self.view_name, request, format) except NoReverseMatch: msg = ( 'Could not resolve URL for hyperlinked relationship using ' @@ -553,7 +142,7 @@ class HyperlinkedIdentityField(Field): 'model in your API, or incorrectly configured the ' '`lookup_field` attribute on this field.' ) - raise Exception(msg % view_name) + raise Exception(msg % self.view_name) def get_url(self, obj, view_name, request, format): """ @@ -562,34 +151,15 @@ class HyperlinkedIdentityField(Field): May raise a `NoReverseMatch` if the `view_name` and `lookup_field` attributes are not configured to correctly match the URL conf. """ - lookup_field = getattr(obj, self.lookup_field, None) - kwargs = {self.lookup_field: lookup_field} - - # Handle unsaved object case - if lookup_field is None: + # Unsaved objects will not yet have a valid URL. + if obj.pk is None: return None - try: - return reverse(view_name, kwargs=kwargs, request=request, format=format) - except NoReverseMatch: - pass - - if self.pk_url_kwarg != 'pk': - # Only try pk lookup if it has been explicitly set. - # Otherwise, the default `lookup_field = 'pk'` has us covered. - kwargs = {self.pk_url_kwarg: obj.pk} - try: - return reverse(view_name, kwargs=kwargs, request=request, format=format) - except NoReverseMatch: - pass - - slug = getattr(obj, self.slug_field, None) - if slug: - # Only use slug lookup if a slug field exists on the model - kwargs = {self.slug_url_kwarg: slug} - try: - return reverse(view_name, kwargs=kwargs, request=request, format=format) - except NoReverseMatch: - pass - - raise NoReverseMatch() + lookup_value = getattr(obj, self.lookup_field) + kwargs = {self.lookup_url_kwarg: lookup_value} + return reverse(view_name, kwargs=kwargs, request=request, format=format) + + +class SlugRelatedField(RelatedField): + def __init__(self, **kwargs): + self.slug_field = kwargs.pop('slug_field', None) |