def resolve(self, serializer, query, view=None):
"""Resolve an ordering.
Arguments:
query: a string representing an API field
e.g: "location.name"
serializer: a serializer instance
e.g. UserSerializer
view: a view instance (optional)
e.g. UserViewSet
Returns:
Double-underscore-separated list of strings,
representing a model field.
e.g. "location__real_name"
Raises:
ValidationError if the query cannot be rewritten
"""
if not self._is_allowed_query(query, view):
raise ValidationError('Invalid sort option: %s' % query)
model_fields, _ = serializer.resolve(query, sort=True)
resolved = '__'.join([Meta.get_query_name(f) for f in model_fields])
return resolved
def _build_requested_prefetches(self, prefetches, requirements, model,
fields, filters, is_root_level):
"""Build a prefetch dictionary based on request requirements."""
meta = Meta(model)
for name, field in six.iteritems(fields):
original_field = field
if isinstance(field, dfields.DynamicRelationField):
field = field.serializer
if isinstance(field, serializers.ListSerializer):
field = field.child
if not isinstance(field, serializers.ModelSerializer):
continue
source = field.source or name
if '.' in source:
raise ValidationError('Nested relationship values '
'are not supported')
if source == '*':
# ignore custom getter/setter
continue
if source in prefetches:
# ignore duplicated sources
continue
related_queryset = getattr(original_field, 'queryset', None)
if callable(related_queryset):
related_queryset = related_queryset(field)
is_id_only = getattr(field, 'id_only', lambda: False)()
is_remote = meta.is_field_remote(source)
is_gui_root = self.view.get_format() == 'admin' and is_root_level
if (related_queryset is None and is_id_only and not is_remote
and not is_gui_root):
# full representation and remote fields
# should all trigger prefetching
continue
# Popping the source here (during explicit prefetch construction)
# guarantees that implicitly required prefetches that follow will
# not conflict.
required = requirements.pop(source, None)
query_name = Meta.get_query_name(original_field.model_field)
prefetch_queryset = self._build_queryset(serializer=field,
filters=filters.get(
query_name, {}),
queryset=related_queryset,
requirements=required)
# There can only be one prefetch per source, even
# though there can be multiple fields pointing to
# the same source. This could break in some cases,
# but is mostly an issue on writes when we use all
# fields by default.
prefetches[source] = Prefetch(source, queryset=prefetch_queryset)
return prefetches
def _get_requested_filters(self, **kwargs):
"""
Convert 'filters' query params into a dict that can be passed
to Q. Returns a dict with two fields, 'include' and 'exclude',
which can be used like:
result = self._get_requested_filters()
q = Q(**result['_include'] & ~Q(**result['_exclude'])
"""
filters_map = kwargs.get('filters_map')
view = getattr(self, 'view', None)
if view:
serializer_class = view.get_serializer_class()
serializer = serializer_class()
if not filters_map:
filters_map = view.get_request_feature(view.FILTER)
else:
serializer = None
out = TreeMap()
for key, value in six.iteritems(filters_map):
# Inclusion or exclusion?
if key[0] == '-':
key = key[1:]
category = '_exclude'
else:
category = '_include'
# for relational filters, separate out relation path part
if '|' in key:
rel, key = key.split('|')
rel = rel.split('.')
else:
rel = None
terms = key.split('.')
# Last part could be operator, e.g. "events.capacity.gte"
if len(terms) > 1 and terms[-1] in self.VALID_FILTER_OPERATORS:
operator = terms.pop()
else:
operator = None
# All operators except 'range' and 'in' should have one value
if operator == 'range':
value = value[:2]
if value[0] == '':
operator = 'lte'
value = value[1]
elif value[1] == '':
operator = 'gte'
value = value[0]
elif operator == 'in':
# no-op: i.e. accept `value` as an arbitrarily long list
pass
elif operator in self.VALID_FILTER_OPERATORS:
value = value[0]
if (operator == 'isnull'
and isinstance(value, six.string_types)):
value = is_truthy(value)
elif operator == 'eq':
operator = None
if serializer:
s = serializer
if rel:
# get related serializer
model_fields, serializer_fields = serializer.resolve(rel)
s = serializer_fields[-1]
s = getattr(s, 'serializer', s)
rel = [Meta.get_query_name(f) for f in model_fields]
# perform model-field resolution
model_fields, serializer_fields = s.resolve(terms)
field = serializer_fields[-1] if serializer_fields else None
# if the field is a boolean,
# coerce the value
if field and isinstance(
field,
(serializers.BooleanField, serializers.NullBooleanField)):
value = is_truthy(value)
key = '__'.join([Meta.get_query_name(f) for f in model_fields])
else:
key = '__'.join(terms)
if operator:
key += '__%s' % operator
# insert into output tree
path = rel if rel else []
path += [category, key]
out.insert(path, value)
return out