eiru_purchases/models/purchase_order.py

# -*- coding: utf-8 -*-
from openerp import api, models

class PurchaseOrder(models.Model):
    _inherit = 'purchase.order'

    '''
    '''
    def action_purchase_confirm(self, cr, uid, ids, context=None):
        if not context:
            context = {}

        assert len(ids) == 1, 'This option should only be used for a single id at a time'
        
        self.signal_workflow(cr, uid, ids, 'purchase_confirm')

        return True