Question

Let´s say I have two PHP classes one called gallery and one called image.

In the class image I want to include the class gallery, and in the class gallery I want to include the class image.

How could this be properly done – or whats the best way to accomplish this?
What I want to be able to do in the end is to use methods of the class gallery in some methods of the class image.

For example: I have a method “delete” in both classes. In the class gallery the method is used to delete a specific gallery – selected by id. But in the class image the method delete also checks if the deleted image was the last one in a gallery – if so this gallery should be deleted by passing the id to the delete method of the class gallery.

How could this be done best? – Or is there a complete different better way of doing something like this?

Thanks for your anwers!

Answer 1

Composition .. the image instance has an instance of the gallery that it belongs to (if it can belong to multiple galleries that complicates things).

class Image {
   private $gallery;
   private $db;
   public function __construct(Gallery $gallery, DB $db) {
      $this->gallery = $gallery;
      $this->db = $db;
   }

   public function delete($id) {
      $this->db->deleteImage($id);
      if ($this->gallery->isEmpty()) {
         $this->gallery->delete($this->gallery->getID());
      }
   }
}