I have created this function which modify the "approved_by" field of the corresponding reference :
@api.multi
def affecter_cap(self):
self.texto = self.list_fermes.farm_name
rec = self.env['affichage.information'].search(['reference','=',self.capture_ref.reference])
rec.approved_by = self.list_fermes.farm_name
I got this erreor when i click in the button which realise this action : ValueError: Invalid leaf reference
Thank you Niyas