Hi

I'm stuck, I tried every example I found, but somehow it still doesn't work. I'd like to open a new view from a button in the statusbar. Here are my two approaches.

I'm extending sale_order, file: sale_order.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <record model="ir.ui.view" id="view_sale_order_form_wizard">
            <field name="name">sale.order.form</field>
            <field name="model">sale.order</field>
            <field name="inherit_id" ref="sale.view_order_form" />
            <field name="arch" type="xml">
                <header>
                    <button type='action' name='%(custom_wizard_ext_view)d' string="Button A" />
                    <button type='object' name='open_wizard' string="Button B" />
                </header>
            </field>
        </record>
    </data>
</openerp>  

The two buttons appear, so everything fine to this point.

Button A:
Should open a new, customize view (just a dummy view at this moment). This view will create products later.

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <record id="custom_wizard_ext_view" model="ir.ui.view">
            <field name="name">product.product.form</field>
            <field name="model">product.product</field>
            <field name="type">form</field>
            <field name="arch" type="xml">
                <data>
                    <field name="name" colspan="4" />
                    <group col="4" colspan="4">
                        <button name="save" string="Save" type="object" colspan="1" />

                    </group>
                </data>
            </field>
        </record>
    </data>
</openerp> 

Shouldn't %(custom_wizard_ext_view)d open this view?

Button B:

Call of a function which is in my file sale_order.py:

from openerp import models, fields


class sale_order(models.Model):
    _inherit = 'sale.order'

    def open_wizard(self, cr, uid, ids, context=None):
        return {
            'type': 'ir.actions.act_window',
            'res_model': 'product.product',
            'view_type': 'form',
            'view_mode': 'form',
            'res_id': 'custom_wizard_ext_view',
            'target': 'new',
        }

When I click "Button B" I get this error:

TypeError: open_wizard() takes exactly 1 argument (5 given) 

Which one is the right approach to open a view from a button in the status bar?