* @author Bernhard Posselt * @copyright Alessandro Cosentino 2012 * @copyright Bernhard Posselt 2012, 2014 */ namespace OCA\News\ArticleEnhancer; use \DOMDocument; use \DOMXpath; use \ZendXml\Security; use \OCA\News\Utility\PicoFeedClientFactory; use \OCA\News\Db\Item; class XPathArticleEnhancer implements ArticleEnhancer { private $maximumTimeout; private $clientFactory; private $regexXPathPair; /** * @param \Utility\PicoFeedClientFactory $clientFactory * @param array $regexXPathPair an associative array containing regex to * match the url and the xpath that should be used for it to extract the * page */ public function __construct(PicoFeedClientFactory $clientFactory, array $regexXPathPair){ $this->clientFactory = $clientFactory; $this->regexXPathPair = $regexXPathPair; } /** * @param \OCA\News\Db\Item $item * @return \OCA\News\Db\Item enhanced item */ public function enhance(Item $item){ foreach($this->regexXPathPair as $regex => $search) { if(preg_match($regex, $item->getUrl())) { list($body, $contentType) = $this->getFile($item->getUrl()); if(preg_match('/(?<=charset=)[^;]*/', $body, $matches)) { $encoding = $matches[0]; $body = mb_convert_encoding($body, 'HTML-ENTITIES', strtoupper($encoding)); } $dom = new DOMDocument(); Security::scan($body, $dom, function ($xml, $dom) { return @$dom->loadHTML($xml, LIBXML_NONET); }); $xpath = new DOMXpath($dom); $xpathResult = $xpath->evaluate($search); // in case it wasnt a text query assume its a dom element and // convert it to text if(!is_string($xpathResult)) { $xpathResult = $this->domToString($xpathResult); } $xpathResult = trim($xpathResult); // convert all relative to absolute URLs $xpathResult = $this->substituteRelativeLinks( $xpathResult, $item->getUrl() ); if($xpathResult) { $item->setBody($xpathResult); } } } return $item; } private function getFile($url) { $client = $this->clientFactory->build(); $client->execute($url); $client->setUserAgent('Mozilla/5.0 AppleWebKit'); return [ $client->getContent(), $client->getEncoding() ]; } /** * Method which converts all relative "href" and "src" URLs of * a HTML snippet with their absolute equivalent * @param string $xmlString a HTML snippet as string with the relative URLs * to be replaced * @param string $absoluteUrl the approptiate absolute url of the HTML * snippet * @return string the result HTML snippet as a string */ protected function substituteRelativeLinks($xmlString, $absoluteUrl) { $dom = new DOMDocument(); $dom->preserveWhiteSpace = false; $isOk = Security::scan($xmlString, $dom, function ($xml, $dom) { // wrap in div to prevent loadHTML from inserting weird elements $xml = '

' . $xml . '

'; return @$dom->loadHTML($xml, LIBXML_NONET | LIBXML_HTML_NODEFDTD | LIBXML_HTML_NOIMPLIED); }); if($xmlString === '' || !$isOk) { return false; } foreach (['href', 'src'] as $attribute) { $xpath = new DOMXpath($dom); $xpathResult = $xpath->query( "//*[@" . $attribute . " " . "and not(contains(@" . $attribute . ", '://')) " . "and not(starts-with(@" . $attribute . ", 'mailto:')) " . "and not(starts-with(@" . $attribute . ", '//'))]"); foreach ($xpathResult as $linkNode) { $urlElement = $linkNode->attributes->getNamedItem($attribute); $abs = $this->relativeToAbsoluteUrl( $urlElement->nodeValue, $absoluteUrl ); $urlElement->nodeValue = htmlspecialchars($abs); } } $xmlString = $dom->saveHTML(); // domdocument spoils the string with line breaks between the elements // strip them $xmlString = str_replace("\n", '', $xmlString); return $xmlString; } /** * Method which builds a URL by taking a relative URL and its corresponding * absolute URL * @param string $relativeUrl the relative URL * @param string $absoluteUrl the absolute URL with at least scheme and host * @return string the resulting absolute URL */ protected function relativeToAbsoluteUrl($relativeUrl, $absoluteUrl) { $base = new \Net_URL2($absoluteUrl); return $base->resolve($relativeUrl); } /** * Method which turns an xpath result to a string * you can customize it by overwriting this method * @param mixed $xpathResult the result from the xpath query * @return string the result as a string */ protected function domToString($xpathResult) { $result = ''; foreach($xpathResult as $node) { $result .= $this->toInnerHTML($node); } return $result; } protected function toInnerHTML($node) { $dom = new DOMDocument(); $dom->appendChild($dom->importNode($node, true)); return trim($dom->saveHTML($dom->documentElement)); } }