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<?php
/**
* ownCloud - News
*
* This file is licensed under the Affero General Public License version 3 or
* later. See the COPYING file.
*
* @author Alessandro Cosentino <cosenal@gmail.com>
* @author Bernhard Posselt <dev@bernhard-posselt.com>
* @copyright Alessandro Cosentino 2012
* @copyright Bernhard Posselt 2012, 2014
*/
namespace OCA\News\ArticleEnhancer;
require_once __DIR__ . '/../3rdparty/Net_URL2/Net/URL2.php';
use \ZendXml\Security;
use \Net_URL2;
use \OCA\News\Db\Item;
use \OCA\News\Utility\SimplePieAPIFactory;
use \OCA\News\Utility\Config;
class XPathArticleEnhancer implements ArticleEnhancer {
private $fileFactory;
private $maximumTimeout;
private $config;
private $regexXPathPair;
/**
* @param \OCA\News\Utility\SimplePieAPIFactory $fileFactory
* @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
* @param \OCA\News\Utility\Config $config
* @internal param \OCA\News\ArticleEnhancer\a $SimplePieFileFactory factory for getting a simple pie file instance
* @internal param int $maximumTimeout maximum timeout in seconds, defaults to 10 sec
*/
public function __construct(SimplePieAPIFactory $fileFactory,
array $regexXPathPair, Config $config){
$this->regexXPathPair = $regexXPathPair;
$this->fileFactory = $fileFactory;
$this->maximumTimeout = $config->getFeedFetcherTimeout();
$this->config = $config;
}
/**
* @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())) {
$file = $this->getFile($item->getUrl());
// convert encoding by detecting charset from header
$contentType = $file->headers['content-type'];
$body = $file->body;
if( preg_match( '/(?<=charset=)[^;]*/', $contentType, $matches ) ) {
$body = mb_convert_encoding($body, 'HTML-ENTITIES', $matches[0]);
}
$dom = new \DOMDocument();
Security::scan($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 single entry
if(!is_string($xpathResult)) {
$xpathResult = $this->domToString($xpathResult);
}
// convert all relative to absolute URLs
$xpathResult = $this->substituteRelativeLinks($xpathResult, $item->getUrl());
if($xpathResult) {
$item->setBody($xpathResult);
}
}
}
return $item;
}
private function getFile($url) {
return $this->fileFactory->getFile(
$url, $this->maximumTimeout, 5, null, 'Mozilla/5.0 AppleWebKit',
false, null, null, null
);
}
/**
* 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;
// return, if xml is empty or loading the HTML fails
$isLoaded = Security::scan($xmlString, $dom, function ($xml, $dom) {
return @$dom->loadHTML($xml, LIBXML_NONET);
});
if(trim($xmlString) === '' || !$isLoaded) {
return $xmlString;
}
// remove <!DOCTYPE
$dom->removeChild($dom->firstChild);
// remove <html></html>
$dom->replaceChild($dom->firstChild->firstChild, $dom->firstChild);
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);
}
}
// save dom to string and remove <body></body>
$xmlString = substr(trim($dom->saveHTML()), 6, -7);
// 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
* For example relative URL "../example/path/file.php?a=1#anchor" and
* absolute URL "https://username:password@www.website.com/subfolder/index.html"
* will result in "https://username:password@www.website.com/example/path/file.php?a=1#anchor"
* @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));
}
}
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