Check if the current document can be print

In some circumstance, we must block printing because there is missing information on the document (eg bad price on the quotation)

to made this customize as possible, we define some specification

If the osv.osv model have a function check_print, we execute it on the current document.
If this function return True we launch the report execution
If this function return False, we raise an error with a message define on the report definition
Otherwise we can raise a JasperException

eg

from osv import osv
from jasper_server.report.report_exception import JasperException
from tools.translate import _

class SaleOrder(osv.osv):
    _inherit = 'sale.order'

    def check_print(self, cr, uid, obj, context=None):
        if obj.state != 'draft':
            raise JasperException(_('Oups'), _('Game Over'))
        return True

SaleOrder()