How to correctly inherit an inherited view in odoo? - odoo-10

Question

I have been trying to target an inherited element in the view, but it's not working for me.
So I have a view that inherits from the form view of hr.contract as shown here:
<record id="hr_contract_view_form_cayor" model="ir.ui.view">
<field name="name">name</field>
<field name="model">hr.contract</field>
<field name="inherit_id" ref="hr_contract.hr_contract_view_form"/>
<field name="arch" type="xml">
<data>
<!-- more elements define with xpath -->
<xpath expr="//field[#name='job_id']" position="after">
<field name="retirement_age"/>
</xpath>
...
<xpath expr="//page[#name='information']" position="after">
<page string="Allowances" groups="hr_payroll.group_hr_payroll_user">
<group>
<group name="allowances_group1">
...
<field name="car_allowance"/>
...
</group>
<group name="allowances_group2">
...
</group>
</group>
</page>
</xpath>
</data>
</field>
</record>
I have defined a new file to inherit from this form view, which adds a new field to it, as follows:
<record id="hr_contract.hr_contract_view_form_inherited" model="ir.ui.view">
<field name="name">hr.contract.grade.rank.form.inherit</field>
<field name="model">hr.contract</field>
<field name="inherit_id" ref="module.hr_contract_view_form_cayor"/>
<field name="arch" type="xml">
<data>
<xpath expr="//group[#name='allowances_group1']" position="inside">
<field name="medical_allowance" />
</xpath>
</data>
</field>
</record>
But when I upgrade my module, I get the following error:
Field `retirement_age` does not exist
How can I correctly inherit from the first one, and add my new field?
Any help will be greatly appreciated, thanks in advance.

Answer 1

Please try this code :
Python :
class HrContract(models.Model):
_inherit = 'hr.contract'
retirement_age = fields.Char(string="Retirement Age:")
XML :
<record id="hr_contract_view_form_cayor" model="ir.ui.view">
<field name="name">name</field>
<field name="model">hr.contract</field>
<field name="inherit_id" ref="hr_contract.hr_contract_view_form"/>
<field name="arch" type="xml">
<data>
<!-- more elements define with xpath -->
<xpath expr="//field[#name='job_id']" position="after">
<field name="retirement_age"/>
</xpath>
</data>
</field>
</record>