OOP constructor frustration

[fandelem]

I cannot get multiple-constructor code working! Argh.

class GuestBook extends IndieBase
{
  // Variables
  var $id; // MYSQL ID number from addEntry() or lookupEntry()
  var $artist_id;
  var $body;
  var $email;
  var $ip;
  var $creation;
  var $db;
  var $display;

  // Constructor
  function GuestBook()
  {
    global $db, $display;

$this->db = $db; // Set our DB pointer
$this->IndieBase();  // Parent Constructor
$this->display = $display; // Set our output pointer.
$arg_list =func_get_args();
$num = count($arg_list);
$name="GuestBook".$num; // Generates something like 'GuestBook1'
switch($num_args)
{
    case 0:
     //clear vars at least
     $this->id = 0;
     $this->artist_id = 0;
     $this->body = "";
     $this->email = "";
    break;
    case 3:
      $this->$name($arg_list[0],$arg_list[1], $arg_list[2]);
    break;
    default: 
      echo "Wrong number of parameters on ".get_class($this)." constructor!";
} // end switch
  } // end Guestbook()


  function GuestBook3($artist_id, $body, $email)
  {
    $this->artist_id = $artist_id;
    $this->body = prepDBText($body);
    $this->email = $email;
  }

}

When I issue this:

$guestbook = new GuestBook("15","testguestbookentry","[e-mail]");

It doesn't work. Period. No error though...

any ideas?

cheers,

k.

[Rub]

Yeah dude, your daughter class first looks for a constructor that shares the class name then the parent class name. Sicne the class "GuestBook" has a method called "GuestBook", the "GuestBook" method is treated as a constructor.

When you instantiate the GuestBook object, the parameters are simply ignored. If you want to initialize your object properties to the values in your object instantiation call, than you should consolidate your two methods or explicity call the "Guestbook3" method.

[CeleronDude]

<?

class Test {
function Test($var){
print $var;
}

}

$a = new Test('hi');
?>

The constructor is nothing more than a function that is executed automatically. It still requires function arguments. In this case you're trying to insert argument into a function that doesn't require any and hence it won't know what to do with the arguments you entered.

[Weedpacket]

Neither Rub nor CeleronDude appear to be familiar with the func_get_args() function.

I'm nervous about the $this->$name(...) bit, myself; it just seems like an extra complication made for the fun of it, and looks like it could well cause problems. You know what $num is at this point, so you know what $name is. So why not just call
$this->GuestBook3($arg_list[0], $arg_list[1], $arg_list[2]);? Or just inline it for that matter?

[Weedpacket]

Another thing to note is that default literals can be specified in the function declaration

function GuestBook($artist_id=0, $body='', $email='')
{
   $this->artist_id=$artist_id;
   //...etc...
}

This will work for both new GuestBook() (in which $artist_id etc. will be given their default values) and new GuestBook(15, "testguestbookentry", "[e-mail]") (where their values are specified in the function call).

[fandelem]

I found the error! Hah.

Notice I have

$num = count($arg_list);

then:

switch($num_args)

dowh.

sorry guys, but thanks for the info. hope this post is useful for anyone else :>

cheers,

k.