New Odoo user here. I'm trying to add a custom view to the HR module where you can only see the remaining vacation days of the employee related to the logged-in user, but I don't know how to make a reference to the logged-in user as there's no field to reference it in the hr.employee model.  

Here's what I have so far:

<openerp>
    <data>
        <record model="ir.ui.view" id="sq_employee_leave_view">
            <field name="name">sqemployeeleaves.form</field>
            <field name="model">hr.employee</field>
            <field name="inherit_id" ref="hr_holidays.view_employee_form_leave_inherit"/>            
            <field name="arch" type="xml">
                <xpath expr="//field[@name='remaining_leaves']" position="replace">
                    <field name="remaining_leaves" attrs="{'invisible':[('user_id', '!=', uid)]}"/>
                </xpath>
            </field>
        </record>
    </data>
</openerp>

This gives me a 'uid is not defined' error.  Can anyone tell me how to go about referencing the current user?  I'm working in Odoo 8.  Thanks!