Example Gallery class in PHP

Gallery.php

<?php

/**
 * Gallery class.
 * A Gallery holds images which can be formatted to html 
 * and displayed onto the a web page
 */
class Gallery
{
  public $id;
  public $name;
  public $description;
  public $defaultImageId;
  public $images = array();
  
  public function __construct($id, $name, $description)
  {
    $this->id = $id;
    $this->name = $name;
    $this->description = $description;
  }

  public function addImage(GalleryImage $image)
  {
    $this->images[] = $image;
  }

  public function removeImage($imageId)
  {
    unset($this->images[$imageId]);
  }

  public function setDefaultImage($imageId)
  {
    this->defaultImageId = $imageId;
  }

  public function showImages()
  {
    if (sizeof($this->images) == 0)
      return "Gallery is empty";

    foreach($this->images as $image)
      $image.toHtml();
  }
}

?>