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, innerjoin=True)
else:
joinload_object = joinload_object.joinedload(
field, innerjoin=True)
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, innerjoin=True)
query = query.options(joinload_object)
return query
def include(self):
"""Return fields to include
:return list: a list of include information
"""
include_param = self.qs.get('include', [])
if current_app.config.get('MAX_INCLUDE_DEPTH') is not None:
for include_path in include_param:
if len(include_path.split('.')) > current_app.config['MAX_INCLUDE_DEPTH']:
raise InvalidInclude("You can't use include through more than {} relationships"
.format(current_app.config['MAX_INCLUDE_DEPTH']))
return include_param.split(',') if include_param else []
def include(self):
"""Return fields to include
:return list: a list of include information
"""
include_param = self.qs.get('include', [])
if current_app.config.get('MAX_INCLUDE_DEPTH') is not None:
for include_path in include_param:
if len(include_path.split(
'.')) > current_app.config['MAX_INCLUDE_DEPTH']:
raise InvalidInclude(
"You can't use include through more than {} relationships"
.format(current_app.config['MAX_INCLUDE_DEPTH']))
if include_param:
param_results = []
for param in include_param.split(','):
if current_app.config['DASHERIZE_API'] is True:
param = param.replace('-', '_')
param_results.append(param)
return param_results
return []
def compute_schema(schema_cls, default_kwargs, qs, include):
"""Compute a schema around compound documents and sparse fieldsets
:param Schema schema_cls: the schema class
:param dict default_kwargs: the schema default kwargs
:param QueryStringManager qs: qs
:param list include: the relation field to include data from
:return Schema schema: the schema computed
"""
# manage include_data parameter of the schema
schema_kwargs = default_kwargs
schema_kwargs['include_data'] = tuple()
# collect sub-related_includes
related_includes = {}
if include:
for include_path in include:
field = include_path.split('.')[0]
if field not in schema_cls._declared_fields:
raise InvalidInclude("{} has no attribute {}".format(
schema_cls.__name__, field))
elif not isinstance(schema_cls._declared_fields[field],
Relationship):
raise InvalidInclude(
"{} is not a relationship attribute of {}".format(
field, schema_cls.__name__))
schema_kwargs['include_data'] += (field, )
if field not in related_includes:
related_includes[field] = []
if '.' in include_path:
related_includes[field] += [
'.'.join(include_path.split('.')[1:])
]
# make sure id field is in only parameter unless marshamllow will raise an Exception
if schema_kwargs.get(
'only') is not None and 'id' not in schema_kwargs['only']:
schema_kwargs['only'] += ('id', )
# create base schema instance
schema = schema_cls(**schema_kwargs)
# manage sparse fieldsets
if schema.opts.type_ in qs.fields:
tmp_only = set(schema.declared_fields.keys()) & set(
qs.fields[schema.opts.type_])
if schema.only:
tmp_only &= set(schema.only)
schema.only = tuple(tmp_only)
# make sure again that id field is in only parameter unless marshamllow will raise an Exception
if schema.only is not None and 'id' not in schema.only:
schema.only += ('id', )
# manage compound documents
if include:
for include_path in include:
field = include_path.split('.')[0]
relation_field = schema.declared_fields[field]
related_schema_cls = schema.declared_fields[field].__dict__[
'_Relationship__schema']
related_schema_kwargs = {}
if 'context' in default_kwargs:
related_schema_kwargs['context'] = default_kwargs['context']
if isinstance(related_schema_cls, SchemaABC):
related_schema_kwargs['many'] = related_schema_cls.many
related_schema_cls = related_schema_cls.__class__
if isinstance(related_schema_cls, str):
related_schema_cls = class_registry.get_class(
related_schema_cls)
related_schema = compute_schema(related_schema_cls,
related_schema_kwargs, qs,
related_includes[field] or None)
relation_field.__dict__['_Relationship__schema'] = related_schema
return schema
