ODOO - How to filter Many2Many field containing zero items - filter

Question

How can I filter an Odoo Many2Many field for containing zero items.
Example: I'm trying to filter tasks that have 0 followers (message_follower_ids).
[['message_follower_ids','=',False]] Returns no results, but there should be many.
Odoo version: 8.0
Frank

Answer 1

message_follower_ids is a compute field.
If you want to search by any compute field you have to write the search method of it in old api it is fnct_search and in that method you can return domain.
In your case message_follower_ids is compute one and also having the fnct_search method. so, whenever you search for follower in search bar in top right corner that method will call and return the domain and you will get your filtered list.
But in that fnct_search You need to change to accomplish your need.
Like this.
class mail_thread(osv.AbstractModel):
_inherit = 'mail.thread'
def _get_followers(self, cr, uid, ids, name, arg, context=None):
fol_obj = self.pool.get('mail.followers')
fol_ids = fol_obj.search(cr, SUPERUSER_ID, [('res_model', '=', self._name), ('res_id', 'in', ids)])
res = dict((id, dict(message_follower_ids=[], message_is_follower=False)) for id in ids)
user_pid = self.pool.get('res.users').read(cr, uid, [uid], ['partner_id'], context=context)[0]['partner_id'][0]
for fol in fol_obj.browse(cr, SUPERUSER_ID, fol_ids):
res[fol.res_id]['message_follower_ids'].append(fol.partner_id.id)
if fol.partner_id.id == user_pid:
res[fol.res_id]['message_is_follower'] = True
return res
def _search_followers(self, cr, uid, obj, name, args, context):
"""Search function for message_follower_ids
Do not use with operator 'not in'. Use instead message_is_followers
"""
fol_obj = self.pool.get('mail.followers')
res = []
for field, operator, value in args:
assert field == name
# TOFIX make it work with not in
assert operator != "not in", "Do not search message_follower_ids with 'not in'"
fol_ids = fol_obj.search(cr, SUPERUSER_ID, [('res_model', '=', self._name), ('partner_id', operator, value)])
if not fol_ids and operator == '=' and value==False:
fol_ids = fol_obj.search(cr, SUPERUSER_ID, [('res_model', '=', self._name), ('partner_id', '!=', value)])
res_ids = [fol.res_id for fol in fol_obj.browse(cr, SUPERUSER_ID, fol_ids)]
res.append(('id', 'not in', res_ids))
else:
res_ids = [fol.res_id for fol in fol_obj.browse(cr, SUPERUSER_ID, fol_ids)]
res.append(('id', 'in', res_ids))
return res
_columns = {
'message_follower_ids': fields.function(_get_followers,fnct_search=_search_followers),
}
Also need to add mail module in dependency list.