atst/atat/domain/common/query.py
2020-03-04 11:51:15 -05:00

82 lines
2.1 KiB
Python

from sqlalchemy.exc import DataError
from sqlalchemy.orm.exc import NoResultFound
from atat.domain.exceptions import NotFoundError
from atat.database import db
class Paginator(object):
"""
Uses the Flask-SQLAlchemy extension's pagination method to paginate
a query set.
Also acts as a proxy object so that the results of the query set can be iterated
over without needing to call `.items`.
"""
def __init__(self, query_set):
self.query_set = query_set
@classmethod
def get_pagination_opts(cls, request, default_page=1, default_per_page=100):
return {
"page": int(request.args.get("page", default_page)),
"per_page": int(request.args.get("perPage", default_per_page)),
}
@classmethod
def paginate(cls, query, pagination_opts=None):
if pagination_opts is not None:
return cls(
query.paginate(
page=pagination_opts["page"], per_page=pagination_opts["per_page"]
)
)
else:
return query.all()
def __getattr__(self, name):
return getattr(self.query_set, name)
def __iter__(self):
return self.items.__iter__()
def __len__(self):
return self.items.__len__()
class Query(object):
model = None
@property
def resource_name(cls):
return cls.model.__class__.lower()
@classmethod
def create(cls, **kwargs):
# pylint: disable=E1102
return cls.model(**kwargs)
@classmethod
def get(cls, id_):
try:
resource = db.session.query(cls.model).filter_by(id=id_).one()
return resource
except (NoResultFound, DataError):
raise NotFoundError(cls.resource_name)
@classmethod
def get_all(cls):
return db.session.query(cls.model).all()
@classmethod
def add_and_commit(cls, resource):
db.session.add(resource)
db.session.commit()
return resource
@classmethod
def paginate(cls, query, pagination_opts):
return Paginator.paginate(query, pagination_opts)