def sorting(self):
"""Return fields to sort by including sort name for SQLAlchemy and row
sort parameter for other ORMs
:return list: a list of sorting information
Example of return value::
[
{'field': 'created_at', 'order': 'desc'},
]
"""
if self.qs.get("sort"):
sorting_results = []
for sort_field in self.qs["sort"].split(","):
field = sort_field.replace("-", "")
if field not in self.schema._declared_fields:
raise InvalidSort("{} has no attribute {}".format(
self.schema.__name__, field))
if field in get_relationships(self.schema):
raise InvalidSort(
"You can't sort on {} because it is a relationship field"
.format(field))
field = get_model_field(self.schema, field)
order = "desc" if sort_field.startswith("-") else "asc"
sorting_results.append({"field": field, "order": order})
return sorting_results
return []
def eagerload_includes(self, query, qs):
"""Use eagerload feature of sqlalchemy to optimize data retrieval for include querystring parameter
:param Query query: sqlalchemy queryset
:param QueryStringManager qs: a querystring manager to retrieve information from url
:return Query: the query with includes eagerloaded
"""
for include in qs.include:
joinload_object = None
if "." in include:
current_schema = self.resource.schema
for obj in include.split("."):
try:
field = get_model_field(current_schema, obj)
except Exception as e:
raise InvalidInclude(str(e))
if joinload_object is None:
joinload_object = joinedload(field)
else:
joinload_object = joinload_object.joinedload(field)
related_schema_cls = get_related_schema(current_schema, obj)
if isinstance(related_schema_cls, SchemaABC):
related_schema_cls = related_schema_cls.__class__
else:
related_schema_cls = class_registry.get_class(
related_schema_cls
)
current_schema = related_schema_cls
else:
try:
field = get_model_field(self.resource.schema, include)
except Exception as e:
raise InvalidInclude(str(e))
joinload_object = joinedload(field)
query = query.options(joinload_object)
return query
def related_model(self):
"""Get the related model of a relationship field
:return DeclarativeMeta: the related model
"""
relationship_field = self.name
if relationship_field not in get_relationships(self.schema):
raise InvalidFilters(
"{} has no relationship attribute {}".format(
self.schema.__name__, relationship_field
)
)
return getattr(
self.model, get_model_field(self.schema, relationship_field)
).property.mapper.class_
def column(self):
"""Get the column object
:param DeclarativeMeta model: the model
:param str field: the field
:return InstrumentedAttribute: the column to filter on
"""
field = self.name
model_field = get_model_field(self.schema, field)
try:
return getattr(self.model, model_field)
except AttributeError:
raise InvalidFilters(
"{} has no attribute {}".format(self.model.__name__, model_field)
)
def _get_relationship_data(self):
"""Get useful data for relationship management"""
relationship_field = request.path.split("/")[-1].replace("-", "_")
if relationship_field not in get_relationships(self.schema):
raise RelationNotFound(
"{} has no attribute {}".format(
self.schema.__name__, relationship_field
)
)
related_type_ = self.schema._declared_fields[relationship_field].type_
related_id_field = self.schema._declared_fields[relationship_field].id_field
model_relationship_field = get_model_field(self.schema, relationship_field)
return (
relationship_field,
model_relationship_field,
related_type_,
related_id_field,
)