message_post on change of state odoo - python-2.7

Question

I am trying to post message on openchatter on state change. i used the following good but nothing happened.
in .py file.
#api.one
#api.depends('state')
def log_prod(self,state):
if state in ["i"]:
msg="Dear User: your account has been update"
return self.message_post(body=msg)
state = fields.Selection([('i','Internship'),('j','Joined')])
on xml
<field name="state" widget="statusbar" statusbar_visible="i,j"/>
Even no error. Thanks in advance

Answer 1

Use #api.onchange('state') instead of #api.depends('state')
#api.onchange('state')
def log_prod(self,state):
if state in ["i"]:
msg="Dear User: your account has been update"
return self.message_post(body=msg)

Answer 2

#api.onchange('state')
def log_prod(self):
if self.state in ["i"]:
msg="Dear User: your account has been update"
return self.message_post(body=msg)

Answer 3

Just add argument tracking=True, in the state field. That's it.

Answer 4

To Enable chatter first you need to inherit your model from mail.mesage class Example:
class sale_order(osv.osv):
_name = "sale.order"
_inherit = ['mail.thread']
This will enable chatter functionality on your Model, now next thing you need todo is:
<record id="view_order_form" model="ir.ui.view">
<field name="name">sale.order.form</field>
<field name="model">sale.order</field>
<field name="arch" type="xml">
<form string="Sales Order" version="7.0">
...
</form>
<sheet>
...
</sheet>
<div class="oe_chatter">
<field name="message_follower_ids" widget="mail_followers" groups="base.group_user"/>
<field name="message_ids" widget="mail_thread"/>
</div>
</field>
</record>
this will add chatter in your form view and then your message_post will show up.
code :
<field name="state" widget="statusbar" statusbar_visible="i,j"/>
is for statusbar not for chatter.
Bests