Hi,

i would like to add some fields to account.move and get them calculated. Let´s say I would like to add two fields - tax_base, tax_amount:

_columns = {
        'tax_base': fields.function(
            _tax_balance, method=True,
            string='Tax base',
            store=True),
        'tax_amount': fields.function(
            _tax_balance, method=True,
            string="Amount Tax",
            store=True),

However, when I try to use following function to calculate these fields (this just should throw zeros, but not functioning) for all account.move objects:

def _tax_balance(self, cr, uid, ids, field_name, arg, context=None):
        res = {}

        for move in self.read(cr, uid, ids, context=context):
            res[move['id']] = {
                'tax_base': 0.0,
                'tax_amount': 0.0,
            }      
        return res

This error appears:

Server Traceback (most recent call last): File "E:\erp7\addons\web\session.py", line 90, in send return openerp.netsvc.dispatch_rpc(service_name, method, args) File "E:\erp7\openerp\netsvc.py", line 296, in dispatch_rpc result = ExportService.getService(service_name).dispatch(method, params) File "E:\erp7\openerp\service\web_services.py", line 626, in dispatch res = fn(db, uid, *params) File "E:\erp7\openerp\osv\osv.py", line 188, in execute_kw return self.execute(db, uid, obj, method, *args, **kw or {}) File "E:\erp7\openerp\osv\osv.py", line 131, in wrapper return f(self, dbname, *args, **kwargs) File "E:\erp7\openerp\osv\osv.py", line 197, in execute res = self.execute_cr(cr, uid, obj, method, *args, **kw) File "E:\erp7\openerp\osv\osv.py", line 185, in execute_cr return getattr(object, method)(cr, uid, *args, **kw) File "E:\erp7\addons\base\module\module.py", line 426, in button_immediate_install return self._button_immediate_function(cr, uid, ids, self.button_install, context=context) File "E:\erp7\addons\base\module\module.py", line 473, in _button_immediate_function _, pool = pooler.restart_pool(cr.dbname, update_module=True) File "E:\erp7\openerp\pooler.py", line 39, in restart_pool registry = RegistryManager.new(db_name, force_demo, status, update_module) File "E:\erp7\openerp\modules\registry.py", line 233, in new openerp.modules.load_modules(registry.db, force_demo, status, update_module) File "E:\erp7\openerp\modules\loading.py", line 354, in load_modules loaded_modules, update_module) File "E:\erp7\openerp\modules\loading.py", line 256, in load_marked_modules loaded, processed = load_module_graph(cr, graph, progressdict, report=report, skip_modules=loaded_modules, perform_checks=perform_checks) File "E:\erp7\openerp\modules\loading.py", line 165, in load_module_graph init_module_models(cr, package.name, models) File "E:\erp7\openerp\modules\module.py", line 385, in init_module_models t[1](cr, *t[2]) File "E:\erp7\openerp\osv\orm.py", line 2807, in _update_store cr.execute(update_query, (ss[1](val), key)) File "E:\erp7\openerp\osv\fields.py", line 1092, in <lambda> self._symbol_set = ('%s', lambda x: float_repr(float_round(__builtin__.float(x or 0.0), TypeError: float() argument must be a string or a number

Thanks for help!