rss-bridge/formats/AtomFormat.php

<?php
/**
* Atom
* Documentation Source http://en.wikipedia.org/wiki/Atom_%28standard%29 and
* http://tools.ietf.org/html/rfc4287
*/
class AtomFormat extends FormatAbstract{

	public function stringify(){
		$https = isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on' ? 's' : '';
		$httpHost = isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : '';
		$httpInfo = isset($_SERVER['PATH_INFO']) ? $_SERVER['PATH_INFO'] : '';

		$serverRequestUri = $this->xml_encode($_SERVER['REQUEST_URI']);

		$extraInfos = $this->getExtraInfos();
		$title = $this->xml_encode($extraInfos['name']);
		$uri = !empty($extraInfos['uri']) ? $extraInfos['uri'] : 'https://github.com/RSS-Bridge/rss-bridge';
		$icon = $this->xml_encode($uri .'/favicon.ico');
		$uri = $this->xml_encode($uri);

		$entries = '';
		foreach($this->getItems() as $item) {
			$entryAuthor = isset($item['author']) ? $this->xml_encode($item['author']) : '';
			$entryTitle = isset($item['title']) ? $this->xml_encode($item['title']) : '';
			$entryUri = isset($item['uri']) ? $this->xml_encode($item['uri']) : '';
			$entryTimestamp = isset($item['timestamp']) ? $this->xml_encode(date(DATE_ATOM, $item['timestamp'])) : '';
			$entryContent = isset($item['content']) ? $this->xml_encode($this->sanitizeHtml($item['content'])) : '';

			$entryEnclosures = '';
			if(isset($item['enclosures'])) {
				foreach($item['enclosures'] as $enclosure) {
					$entryEnclosures .= '<link rel="enclosure" href="'
					. $this->xml_encode($enclosure)
					. '"/>'
					. PHP_EOL;
				}
			}

			$entries .= <<<EOD

	<entry>
		<author>
			<name>{$entryAuthor}</name>
		</author>
		<title type="html">{$entryTitle}</title>
		<link rel="alternate" type="text/html" href="{$entryUri}" />
		<id>{$entryUri}</id>
		<updated>{$entryTimestamp}</updated>
		<content type="html">{$entryContent}</content>
		{$entryEnclosures}
	</entry>

EOD;
		}

	$feedTimestamp = date(DATE_ATOM, time());
	$charset = $this->getCharset();

		/* Data are prepared, now let's begin the "MAGIE !!!" */
		$toReturn = <<<EOD
<?xml version="1.0" encoding="{$charset}"?>
<feed xmlns="http://www.w3.org/2005/Atom" xmlns:thr="http://purl.org/syndication/thread/1.0">

	<title type="text">{$title}</title>
	<id>http{$https}://{$httpHost}{$httpInfo}/</id>
	<icon>{$icon}</icon>
	<logo>{$icon}</logo>
	<updated>{$feedTimestamp}</updated>
	<link rel="alternate" type="text/html" href="{$uri}" />
	<link rel="self" href="http{$https}://{$httpHost}{$serverRequestUri}" />
{$entries}
</feed>
EOD;

		// Remove invalid characters
		ini_set('mbstring.substitute_character', 'none');
		$toReturn = mb_convert_encoding($toReturn, $this->getCharset(), 'UTF-8');
		return $toReturn;
	}

	public function display(){
		$this
			->setContentType('application/atom+xml; charset=' . $this->getCharset())
			->callContentType();

		return parent::display();
	}

	private function xml_encode($text){
		return htmlspecialchars($text, ENT_XML1);
	}
}