php polymorphism - Call a parent function in polymorphed child function - problem with get_class($this)

Question

I created a function to automatically assign values from a select in whatever matching variables available in the related class

class FR_Object{

    protected $me;

    public function __construct()
      {
          $this->me = new ReflectionClass($this);
      }

 public function setFrom($data)
      {
          if (is_array($data) && count($data)) {
              $valid = get_class_vars(get_class($this));
              foreach ($valid as $var => $val) {
                  if (isset($data[$var])) {
                      $this->$var = $data[$var];
                  }
              }
          }
      }
}

Parent class:

class FR_Event extends FR_Object_DB {

    public $EventsID;
    public $Subject;
    public $Description;
    public $UserID;
    public $Username;
    public $Address;
    public $Longitude;
    public $Latitude;
    public $EventStartDate;
    public $EventEndDate;
    public $EventsTypeID;
    public $CountryID;
    public $CityID;
    public $Status;
    public $Lang;
    public $When;

public function getLang($lang){

        $sql = "SELECT      e.EventsID, Subject, Description, UserID, Username, Address, Longitude, Latitude, EventStartDate, EventEndDate, EventsTypeID, CountryID, CityID, Status, Lang
                FROM        Events e
                INNER JOIN  EventsDetails d
                    ON      e.EventsID = d.EventsID
                WHERE       e.EventsID = " . $this->EventsID .
               "   AND         Lang = " . $lang;


        $result = $this->selectOneRow($sql);
        if ($result) {
            $this->setFrom($result);
        }else{
            $this->Lang = null;
            $this->Subject = null;
            $this->Description = null;
        }
    }
}

child class:

class FR_Invitation extends FR_Event{

    public $invites;

public function getLang($lang){
        parent::getLang($lang);

        $sql = "SELECT      InvitationID, Email, InvitationDate, ConfirmationName, UserID
                FROM        Invitation i
                INNER JOIN  ConfirmationStatus s on i.ConfirmationStatusID = s.ConfirmationStatusID
                WHERE       EventsID = " . $this->EventsID .
               " AND        Lang = " . $this->Lang;

        $this->invites = $this->select($sql);
    }
}

My problem is that a function in a parent class is called in a child class like this:

parent::getLang($lang).

parent::getLang($lang) uses setFrom but at that point $this is not the parent class anymore.

It's the child!

Does someone see a way to alter this function for normal usage and when called by way of parent:: or do I have to just throw it to the bin and go for more traditional (and longer) methods?

Answer 1

Simply don't overwrite the setForm function in the child class and it will use the setForm in the parent class it is extending.

However, it seems to have a clear misunderstanding of OO inheritance. Best you take the time read through the relevant documentation .

You need to use setter injection (google it) and pass either the result of get_class_vars or the calling class name.

class FR_Object {
    public function setFrom($data, $vars) {
         if (is_array($data) && count($data)) {
              $valid = $vars;
              foreach ($valid as $var => $val) {
                   if (isset($data[$var])) {
                       $this->$var = $data[$var];
                   }
              }
         }
    }
}

class FR_Invitation {
    public function setFrom($data, $vars) {
        parent::setForm($data, $vars);
    }
}

Answer 2

I don't see why you couldn't leave it as is. The only consequence in that case would be that $invites would also be returned by the get_class_vars() call.

An option to do the behaviour you are talking about could be to pass an optional parameter to the setFrom() function.

public function setFrom($data, $class = null)
{
    $class = $class == null ? get_class($this) : $class;
    if (is_array($data) && count($data)) {
        $valid = get_class_vars(get_class($this));
        foreach ($valid as $var => $val) {
            if (isset($data[$var])) {
            $   this->$var = $data[$var];
            }
        }
    }
}

Then in your parent, Event class use this call to setFrom.

$this->setFrom($result, get_class());