Hi all,

How to check if my one2many field have no value

.when I save a record I make product_id a one2many field require =True.but after  saving this record it will not shows warning it saved.how to avoid this condition

Below attached my code its not showing alert..

class ServiceDetails(models.Model): 
 _name='service.info' 
 service_ids=fields.Many2one('crm.lead','Service')   
 product_id=fields.Many2one('product.product', 'Service Type',required=True)   
 details=fields.Char('Remarks')
class crm_lead(models.Model):   
 _inherit='crm.lead' 
crm_lead_ids=fields.One2many('service.info','service_ids','Service Details',required=True)

  @api.model   
  def create(self, values):  
      if self.crm_lead_ids:  
          rec = super(crm_lead, self).create(values) 
      else:     
     raise Warning('You can not add instructor as a attendee')   
     return rec