Thanks MML,

i had to go with a different solution this time since i didn´t have acces to the default field in the sales order line. 

Peter

You can use the following python expression in the "Default Value" field of the field in the sales order line to insert a short text if the field is empty:

if not self.field_name:
self.field_name = 'Short Text'

Here, field_name is the name of the field you want to set the default value for. You can replace 'Short Text' with the desired text. This expression will check if the field is empty (i.e. its value is False), and if so, set its value to the specified text.

You can use this expression in the default_get method of the sales order line model to set the default value for the field when a new sales order line is created. For example:

ef default_get(self, fields):
res = super(SaleOrderLine, self).default_get(fields)
if 'field_name' in fields:
if not res.get('field_name'):
res['field_name'] = 'Short Text'
return res

Here, SaleOrderLine is the name of your sales order line model.

MML