I have some form views similar to `account.voucher.receipt.dialog.form` (`odoo/addons/account_voucher/voucher_payment_receipt_view.xml`).

- Some `field` tags get their default values which were defined in the Model,

- Some `field` tags get their default values from on change methods (defined by `on_change` attributes).

I want to bypass these form views and automate the process, so I need to know beforehand these default field values.

In that way, I only need to add additional field values if needed, then call the `create` method on the model. (I'm using Odoo v8).

How can I achieve that without manual tracing the fields and their corresponding default values/onchange functions?