Question

I have two classes ClassA and ClassB. ClassA always needs an template file name, and ClassB extends ClassA.

In usual cases when a ClassB instance is created, the user has to specify the template file name. Like:

$classB = new ClassB('index');

But now I created a ClassX which extends ClassA, and when the user uses ClassX, he must not specify anything. It’s a class that just creates a button, so it knows by itself what the template file for this is like.

So the user just wants to call:

$bttn = new ClassX();

and internally the constructor of ClassA is called with ‘button_template’.

To do this, I see these choices:

A)

public function __construct() {
    $tplName = func_get_arg(0);
    if (!isset($tplName)) {
        $tplName = 'button_template';
    }
    parent::__construct($tplName);
}

Or B)

public function __construct($tplName='button_template') {
    if (!isset($tplName)) {
        $tplName = 'index';
    }
    parent::__construct($tplName);
}

Or C)

public function __construct($tplName='button_template') {
    parent::__construct($tplName);
}

Which one is the best? And why?

Answer 1

I think this is the best way:

#Class A:
public function __contruct($template){
  //do stuff
}

#Class X extends A
public function __contruct(){
   parent::__construct('button_template')
}

I feel this is the best way because Class A should not be concerned about What Class C wants (Case A) And Class C should not accept anything other then buton_template (Case B and C)