'Get source name for the translation. If object type is model, return
the value stored in db. Otherwise, return value store in src field.'

@api.depends('type', 'name', 'res_id')
def _compute_source(self):

    for record in self:
        record.source = record.src
        if (record.type != 'model'):
            continue
        (model_name, field_name) = record.name.split(',')
        if (model_name not in self.env):
            continue
        model = self.env[model_name]
        field = model._fields.get(field_name)
        if (field is None):
            continue
        if (not callable(field.translate)):
            result = model.browse(record.res_id).with_context(lang=None).read([field_name])
            record.source = (result[0][field_name] if result else False)
