thetool/application/ContractconfigGroup/ContractconfigGroup.php

<?php

class ContractconfigGroup extends mfBaseModel {
  private $items;
  private $value;
  
  
  public function getProperty($name) {
    if($this->$name == null) {
      
      if($name == "items") {
        $this->items = ContractconfigItemModel::search(['group_id' => $this->id]);
        return $this->items;
      }
      
      $classname = ucfirst($name);
      $idfield = $name."_id";
      $this->$name = new $classname($this->$idfield);
      
      if($this->$name->id) {
        return $this->$name;
      } else {
        return null;
      }
    }
    
    return $this->$name;
  }
  
}