Odata filtering for Flask-Smorest with Flask-Sqlalchemy

Add odata-like filtering and sorting on top of flask-smorest functionality

Usage

The primary use case is as a wrapper around the flask-smorest Blueprint class. It will add the odata filter and orderby query params and apply them to the returned model from a MethodView.

from http import HTTPStatus
from flask_smorest import Api, Page
from flask.views import MethodView

from odata import Blueprint

api = Api(app)


class CursorPage(Page):
    @property
    def item_count(self):
        return self.collection.count()


resources = Blueprint(
    'resources',
    __name__,
    url_prefix='/',
    description='root resources',
)

@resources.route('/users')
class User(MethodView):

    @resources.response(HTTPStatus.OK, schemas.User(many=True))
    @resources.paginate(CursorPage)
    @resources.odata(db.session)
    def get(self):
        return models.User

api.register_blueprint(resources)

It will also add docs so the params will appear in Swagger/Redoc.

Features

Filter operators

Multiple filter operations can be joined with and and or

Filter by joined properties

It is possible to filter by a joined property, even if that property isn't returned in the payload. Use a forward-slash (/) to indicate a join.

For example: /users?filter=roles/name eq "admin" would return all users that have a related role with name 'admin'.

Works for one-to-many and many-to-many.

To search for empty or non-empty relations, use eq null or ne null respectively. For example, to filter for users with no roles assigned: /users?filter=roles eq null

Ordering

Use the orderby query parameter to sort by a top-level property or joined property, ascending or descending.

Examples:

• /users?orderby=id
• /users?orderby=id desc
• /users?orderby=supervisor/username
• /users?filter=isActive eq true&orderby=logins desc

AND / OR

Filters can be combined with and and or. Nested filtering with parens is allowed.

Examples:

• isActive eq true or isActive eq false
• createdTime ge 2021-01-01T00:00:00 and createdTime le 2021-02-01T23:59:59 and userId eq 1
• (username eq 'user2' and logins eq 100 and isActive eq false) or (logins gt 1 and username eq 'user3') or contains(note,'backup') or (logins gt 1000 and username eq 'user4' and supervisor/id eq 1)