app/helpers/carts/data_classes.py

# Copyright 2018 Google LLC.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


"""
Data class for cart items.
"""


from dataclasses import dataclass

@dataclass
class CartItem:
    """
    Data class for items in cart.
    """
    item_id: str
    modify_time: str
    uid: str
    document_id: str = None

    @staticmethod
    def deserialize(document):
        """
        Helper function for parsing a Firestore document to a CartItem object.

        Parameters:
           document (DocumentSnapshot): A snapshot of Firestore document.

        Output:
           A CartItem object.
        """

        data = document.to_dict()
        if data:
            return CartItem(
                document_id=document.id,
                item_id=data.get('item_id'),
                modify_time=data.get('modify_time'),
                uid=data.get('uid')
            )

        return None