Alipay - Route which creates the source and returns external redirection url

routes.py

@alipay_blueprint.route('/create_source/<string:order_identifier>', methods=['GET', 'POST'])
def create_source(order_identifier):
    """
    Create a source object for alipay payments.
    :param order_identifier:
    :return: The alipay redirection link.
    """
    try:
        order = safe_query(db, Order, 'identifier', order_identifier, 'identifier')
        source_object = AliPayPaymentsManager.create_source(amount=int(order.amount), currency='usd',
                                                            redirect_return_uri=url_for('alipay_blueprint.alipay_return_uri',
                                                            order_identifier=order.identifier, _external=True))
        order.order_notes = source_object.id
        save_to_db(order)
        return jsonify(link=source_object.redirect['url'])
    except TypeError:
        return BadRequestError({'source': ''}, 'Source creation error').respond()