#!/usr/local/bin/php
<?php
class MakeCustomRss extends DOMDocument {


	private $dom;

	private static $rss_info_arr = [
		'rss' =>
			[[
				'version' => '2.0',
				'xmlns:content' => 'http://purl.org/rss/1.0/modules/content/',
				'xmlns:wfw' => 'http://wellformedweb.org/CommentAPI/',
				'xmlns:dc' => 'http://purl.org/dc/elements/1.1/',
				'xmlns:atom' => 'http://www.w3.org/2005/Atom',
				'xmlns:sy' => 'http://purl.org/rss/1.0/modules/syndication/',
				'xmlns:slash' => 'http://purl.org/rss/1.0/modules/slash/'
			],
			'channel' =>
				[null,
				'title'=> [null,'WIDE POST SPACE'],
				'atom:link' =>
					[['href' => 'https://widepost.space/feed/',
						'rel' => 'self',
						'type' => 'application/rss+xml'
					]],
					'item' =>
						[null,
						'title' => [null,'テスト'],
						'link' => [null,'https://widepost.space/blog/2017/11/']
						]
				]
			]
	];

	public function __construct() {
		$this->dom = new DOMDocument('1.0', 'UTF-8');
		$this->domAppend($this->dom, self::$rss_info_arr);
	}

	public function appendItem(){
		//$this->dom->documentElement->appendChild($this->dom->createElement('item','アイテムの値'));
		$xpath = new DOMXPath($this->dom);
		$xpath->query('//channel')->item(0)->appendChild($this->dom->createElement('item','アイテムの値'));
	}

	public function saveDom() {
		header("Content-Type: text/xml");
		return $this->dom->saveXML();
	}

	private function domAppend($n, $ele_arr)
	{
		//global $dom;

		if(!is_array($ele_arr) || empty($ele_arr)){
			 return $n;
		}
		reset($ele_arr);

		$local_n = $n;
		foreach ($ele_arr as $key => $ele) {

			$value = null;
			if(is_array($ele) && !empty($ele[1]) && !is_array($ele[1])){
				$value = strval($ele[1]);
			}
			$local_n = $n->appendChild($this->dom->createElement($key,$value));
			$setAttr_val = null;
			if(is_array($ele) && $ele != null){
				$setAttr_val = array_splice($ele, 0, 1);
				$local_n = $this->setAttr($local_n, $setAttr_val[0]);
				if(!empty(reset($ele)) && is_array(reset($ele)) ){
					$local_n = $this->domAppend($local_n, $ele);
				}
			}
		}
		return $n;
	}

	private function setAttr($n, $attr_arr){
		foreach ((array)$attr_arr as $key => $attr) {
			$n->setAttribute($key, $attr);
		}
		return $n;
	}

}

$rss = new MakeCustomRss();
$rss->appendItem();
$rss->appendItem();
$rss->appendItem();
$rss->appendItem();
echo $rss->saveDom();

?>