ddd.php

<?php  


class Author
{
	
	private $id, $membership, $posts = [];

	// Pseudo code 1
	public function __construct($id, $membership, $posts)
	{
		$this->id = $id;
		$this->membership = $membership;
		$this->posts = $posts;
	}
	
	public function createNewPost($id, $title, $content)
	{
		
		// Golden Membership
		if( count($this->posts)	>= 1000000) throw new Exception("Exceed Membership limitation");
		// Silver Membership
		if( count($this->posts)	>= 500000) throw new Exception("Exceed Membership limitation");
		// Bronze Membership
		if( count($this->posts)	>= 300000) throw new Exception("Exceed Membership limitation");
		
		$post = new Post( $id, $title, $content);
		return PostCreatedEvent($post);	
	} 
	
	// Pseudo code 2
	public function __construct($id, $membership)
	{
		$this->id = $id;
		$this->membership = $membership;
	}

	public function createNewPost($id, $title, $content, ExceedMembershipLimitation $specification)
	{
		
		if( $specification->isSatisfiedBy( $this->id, $this->membership ) )
		{
			throw new Exception("Exceed Membership limitation");
		}
		
		$post = new Post( $id, $title, $content);
		return PostCreatedEvent($post);	
	}

}