That solution is not thread safe because multiple users using the same form will be replacing the value of the _new_dummy_id_variable property of the class. How you need to call another_method method? beause dummy fields will lost it's value only when you save the form because of the set void method. Used in on_changes or to filter others fields it will work until you save and load the form again

If you don't describe properly what you need, we are blind to give you a solution

That is true. I didn't think about other users possibly changing the property at the same time. What I am trying to do is check what the partners pricelist is set to before creating a new sales order. If the partner has a 'Manual' pricelist selected for them, then a dialog opens up prompting the user to select another valid pricelist for the order so that the right pricing is calculated for the products. Otherwise it creates the order with the other valid pricelists. The point of the dummy field is to list the other pricelists for the user to choose from without actually changing it on the partner record. So when the dialog opens, it displays the dummy pricelist field for the user to select, then creates the order with the new pricelist id. Im just not sure how to do this in odoo without adding a many2one field on the database. Thank you for your help

solved?