Odoo 10

Hi,

In form view of model 'AM' I have O2M field to model 'BM'. In this tree view I have button with connected method 'connected_method' which changes values of field 'state' in form view of model 'AM'. The problem is that I don't see change on frontend, but there is change in database! When I refreshes (F5) page then the changes outcome. Now I am returning action with tag 'reload', but it is soo slow. Is there any better solution which not reloads whole page, but only necessary fields?

connected method:

def connected_method(self):

     self.field_model_am.state = 'done'

     return {
         'type': 'ir.actions.client',
         'tag': 'reload'
     }