Hi,

To make computed fields read-only after a record is saved in Odoo, define the field with store=True and make it computed only when the record is new. In the XML view, use the readonly attribute to set the field as read-only once the record has been created. Additionally, override the write method to prevent further changes to the computed field after the record is saved.

For example set the attribute as following to set the field readonly if the record is created:

<field name="computed_field" readonly="id"/>

Hope it helps.

Hi Cybrosys:

Thanks for your reply.  Once record saved, what i want to be unchangable is the dependency,  such as the field 'country_code' in the following example.  Anyway,  i think the basic mechanism to dynamically set a field 'readonly' is same as your solution.

I am thinking to apply some other fields in the 'readonly ' expression, like 'state'.  

Once the record turns to official , the dependency field is readonly ;  Once the record roll back to 'draft' , the dependency field can be modified as usual.