Hi,

I just start my experience with Odoo and try to make my first module for user wich work with Timesheet. I want create module that count at real time hours of Login user and show this hours at hr timesheet sheet.sheet. 

When I install this module and try to go to Timesheet menu I get this error:

Traceback (most recent call last):
  File "C:\odoo-10.0\odoo\http.py", line 642, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "C:\odoo-10.0\odoo\http.py", line 684, in dispatch
    result = self._call_function(**self.params)
  File "C:\odoo-10.0\odoo\http.py", line 334, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "C:\odoo-10.0\odoo\service\model.py", line 101, in wrapper
    return f(dbname, *args, **kwargs)
  File "C:\odoo-10.0\odoo\http.py", line 327, in checked_call
    result = self.endpoint(*a, **kw)
  File "C:\odoo-10.0\odoo\http.py", line 942, in __call__
    return self.method(*args, **kw)
  File "C:\odoo-10.0\odoo\http.py", line 507, in response_wrap
    response = f(*args, **kw)
  File "C:\odoo-10.0\addons\web\controllers\main.py", line 895, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "C:\odoo-10.0\addons\web\controllers\main.py", line 887, in _call_kw
    return call_kw(request.env[model], method, args, kwargs)
  File "C:\odoo-10.0\odoo\api.py", line 689, in call_kw
    return call_kw_multi(method, model, args, kwargs)
  File "C:\odoo-10.0\odoo\api.py", line 680, in call_kw_multi
    result = method(recs, *args, **kwargs)
  File "C:\odoo-10.0\odoo\models.py", line 3038, in read
    data[record][name] = convert(record[name], record, use_name_get)
  File "C:\odoo-10.0\odoo\models.py", line 5251, in __getitem__
    return self._fields[key].__get__(self, type(self))
  File "C:\odoo-10.0\odoo\fields.py", line 927, in __get__
    self.determine_value(record)
  File "C:\odoo-10.0\odoo\fields.py", line 1041, in determine_value
    self.compute_value(recs)
  File "C:\odoo-10.0\odoo\fields.py", line 993, in compute_value
    self._compute_value(records)
  File "C:\odoo-10.0\odoo\fields.py", line 984, in _compute_value
    getattr(records, self.compute)()
  File "C:\odoo-10.0\addons\attendance\models\login.py", line 26, in _compute_time_difference
    if attendance.check_out:
AttributeError: 'hr_timesheet_sheet.sheet' object has no attribute 'check_out'

login.py:

from openerp import api, fields, models
from odoo.tools.translate import _
from odoo.exceptions import UserError
import logging
_logger = logging.getLogger(__name__)

class HrTimesheetSheet(models.Model):
    _inherit = 'hr_timesheet_sheet.sheet'

    time_difference = fields.Float(compute='_compute_time_difference', string='Time Difference')
       @api.multi

    def _compute_time_difference(self):
        for attendance in self:
            if attendance.check_out:
                time_end = fields.Datetime.from_string(attendance.check_out)
            else:
                time_end = fields.Datetime.from_string(
                    str(fields.Datetime.context_timestamp(
                        self, timestamp=fields.datetime.now()
                    ))
                )
            time_start = fields.Datetime.from_string(attendance.check_in)
            delta = time_end - time_start
            # Timedelta object has no minutes nor hours fields
            hours_difference = delta.seconds / 3600.0 + delta.days * 24
            attendance.time_difference = hours_difference

Views:

<openerp>
    <data noupdate="0">
        <record id="hr_timesheet_sheet_form_work_hours" model="ir.ui.view">
            <field name="name">timesheet.sheet.form.new</field>
            <field name="model">hr_timesheet_sheet.sheet</field>
            <field name="inherit_id" ref="hr_timesheet_attendance.hr_timesheet_sheet_form"/>
            <field name="arch" type="xml">
                <xpath expr="//field[@name='total_difference']" position="after">
                    <field name="time_difference" widget="float_time" sum="Attendance Time"/>
                </xpath>
            </field>
        </record>

 </data>
</openerp>