Question

Let’s say I have three classes. One being the parent and two being “childs”. However, I’m not using class - extends -:

class root
{
   function root(){
      $this->son = new son();
      $this->daughter = new daughter();
   }
}
class son
{
 ...
}
class daughter
{
  ...
}

How could I call a function of son from a function of daughter? In other words, how could I reference the class root from son/daughter so that I could call functions of each other, from each other?

Answer 1

A classic case of dependency injection.

class root {

   function root() {
      $this->son = new son($this);
      $this->daughter = new daughter($this);
   }

}

class son {

   function __construct($parent) {
       $this->parent = $parent;
   }

   function foo() {
       $this->parent->daughter->bar();
   }

}

Just be careful not to create rigid dependencies between classes that shouldn’t have them. Inheritance may be the better way to go. Alternatives include the registry pattern and factory patterns.