sonata_type_collection : set default field value from current entity instance
I found the solution, and it was quite simple, i'm ashamed =__="I forgot to set a reference to the MachineInfo in the newly instantiated MachinePart
public function addMachinePart(MachinePartsInfo $machineParts) { $machineParts->setMachineInfo($this); //Missed this line $this->machineParts[] = $machineParts; return $this;}I hope this can help someone in the future :)