Restrict Deletion of Attachments

This module adds deletion restrictions to attachments (files linked to records such as invoices, sales orders or contacts).

In Settings, under the user default rights block, you find "Restrict Deletion on Attachments". You choose a global level: no restriction, only the owner and administrators, a custom list of groups and users, or a combination of owner plus custom list. When a custom level is chosen, extra fields appear to pick the authorized groups and users.

On each model (document type) form, a "Restrict Attachment Deletion" field lets you override the global setting for that specific model, with the same choices. If you pick a custom level, you can also select the groups and users allowed to delete attachments for that model.

On user and group forms, a new "Attachment Deletion Models" tab lets you list the document types for which that user or group may delete attachments. Only models set to a custom restriction can be selected there.

When someone tries to delete an attachment without permission, Odoo blocks the action and shows an error listing the users who are allowed. Administrators and superusers are not restricted.