I have something like this in V17,

class StockPickingType(models.Model): 
 _inherit = 'stock.picking'

@api.onchange('picking_type_id', 'partner_id') 
def _onchange_picking_type_id(self):
res = super()._onchange_picking_type_id()
...
self.move_ids.unlink() 
product_ids = self.env['product.product'].sudo().search([('categ_id', 'in', [5,6])])
move_lines=[]
 for product_id in product_ids: 
​data = (0, 0, { 'product_id': product_id.id}) 
​move_lines.append(data) 
if move_lines: 
​self.move_ids.write(move_lines)
...
return res


1. The problem is the write operation does not work. If i do a print statement right after the write operation (print(self.move_ids)), there is no stock.move record. I feel its something to do with creating a new picking from kanban view. Any help would be appreciated. I have been on this for sometime now.

2. Also if I add some items in the picking manually and I change the operation type (you have to make it visible first), the items I added are removed from the list. Where in the code base does this happen?