crm.activity inherits mail.message.subtype with the field subtype_id
Before rendering "chatter.ChatComposer", the internal subtypes are fetched
on model mail.message.subtype(in function "fields_view_get").
But when deleting a crm.activity, the linked mail.message.subtype was not
deleted.
Used case:
When deleting a crm.activity, the activity still appeared in the chatter
if you log an internal note for an opportunity as an employee.
opw:670654
to define custom light workflows on opportunities.
Activities are linked to mail.message.subtype through inheritance.
This means that the follow mechanism works for activities. When
an activity is done, a message with the matching subtype is posted
on the opportunity.
Activities are internal by default. They are only visible by
employees.
A shortcut in the 'log a note' chatter option allows to post a
note linked to an activity (subtype).
Goffin Simon