please correct me where i'm wrong / or suggest me best way to achieve my goal ...
in xml
```
<field name="ssr_line" on_change="onchange_product(ssr_line)">
```
in python
```
class ssr_line(models.Model):
_name="ssr.line"
def onchange_product(self, order_line):
mylist = []
if order_line != []:
for line in order_line:
for loop in line:
if isinstance(loop, dict):
mylist.append(loop['product_id'])
if len(mylist) != len(set(mylist)): raise exceptions.ValidationError('Product Should be Unique')
return True
```
nathig happen no error no out put no result
correct me or sugeest me othe way
