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|
<?php
namespace andreskrey\Readability;
use andreskrey\Readability\NodeClass\DOMDocument;
use andreskrey\Readability\NodeClass\DOMAttr;
use andreskrey\Readability\NodeClass\DOMCdataSection;
use andreskrey\Readability\NodeClass\DOMCharacterData;
use andreskrey\Readability\NodeClass\DOMComment;
use andreskrey\Readability\NodeClass\DOMDocumentFragment;
use andreskrey\Readability\NodeClass\DOMDocumentType;
use andreskrey\Readability\NodeClass\DOMElement;
use andreskrey\Readability\NodeClass\DOMNode;
use andreskrey\Readability\NodeClass\DOMNotation;
use andreskrey\Readability\NodeClass\DOMProcessingInstruction;
use andreskrey\Readability\NodeClass\DOMText;
/**
* Class Readability
*/
class Readability
{
/**
* @var string|null
*/
protected $title = null;
/**
* @var string|null
*/
protected $content = null;
/**
* @var string|null
*/
protected $image = null;
/**
* @var string|null
*/
protected $author = null;
/**
* @var Configuration
*/
private $configuration;
/**
* @var array
*/
private $regexps = [
'unlikelyCandidates' => '/banner|breadcrumbs|combx|comment|community|cover-wrap|disqus|extra|foot|header|legends|menu|modal|related|remark|replies|rss|shoutbox|sidebar|skyscraper|social|sponsor|supplemental|ad-break|agegate|pagination|pager|popup|yom-remote/i',
'okMaybeItsACandidate' => '/and|article|body|column|main|shadow/i',
'extraneous' => '/print|archive|comment|discuss|e[\-]?mail|share|reply|all|login|sign|single|utility/i',
'byline' => '/byline|author|dateline|writtenby|p-author/i',
'replaceFonts' => '/<(\/?)font[^>]*>/gi',
'normalize' => '/\s{2,}/',
'videos' => '/\/\/(www\.)?(dailymotion|youtube|youtube-nocookie|player\.vimeo)\.com/i',
'nextLink' => '/(next|weiter|continue|>([^\|]|$)|»([^\|]|$))/i',
'prevLink' => '/(prev|earl|old|new|<|«)/i',
'whitespace' => '/^\s*$/',
'hasContent' => '/\S$/',
// \x{00A0} is the unicode version of
'onlyWhitespace' => '/\x{00A0}|\s+/u'
];
private $defaultTagsToScore = [
'section',
'h2',
'h3',
'h4',
'h5',
'h6',
'p',
'td',
'pre',
];
/**
* @var array
*/
private $alterToDIVExceptions = [
'div',
'article',
'section',
'p',
// TODO, check if this is correct, #text elements do not exist in js
'#text',
];
private $dom;
/**
* Readability constructor.
*
* @param Configuration $configuration
*/
public function __construct(Configuration $configuration)
{
$this->configuration = $configuration;
// To avoid having a gazillion of errors on malformed HTMLs
libxml_use_internal_errors(true);
}
public function parse($html)
{
$this->dom = $this->loadHTML($html);
$this->metadata = $this->getMetadata();
$this->metadata['image'] = $this->getMainImage();
// Checking for minimum HTML to work with.
if (!($root = $this->dom->getElementsByTagName('body')->item(0)) || !$root->firstChild) {
return false;
}
$parseSuccessful = true;
while (true) {
$root = $root->firstChild;
$elementsToScore = $this->getNodes($root);
$result = $this->rateNodes($elementsToScore);
/*
* Now that we've gone through the full algorithm, check to see if
* we got any meaningful content. If we didn't, we may need to re-run
* grabArticle with different flags set. This gives us a higher likelihood of
* finding the content, and the sieve approach gives us a higher likelihood of
* finding the -right- content.
*/
// TODO Better way to count resulting text. Textcontent usually has alt titles and that stuff
// that doesn't really count to the quality of the result.
$length = 0;
foreach ($result->getElementsByTagName('p') as $p) {
$length += mb_strlen($p->textContent);
}
if ($result && mb_strlen(preg_replace('/\s/', '', $result->textContent)) < $this->getConfig()->getOption('wordThreshold')) {
$this->dom = $this->loadHTML($html);
$root = $this->dom->getElementsByTagName('body')->item(0);
if ($this->getConfig()->getOption('stripUnlikelyCandidates')) {
$this->getConfig()->setOption('stripUnlikelyCandidates', false);
} elseif ($this->getConfig()->getOption('weightClasses')) {
$this->getConfig()->setOption('weightClasses', false);
} elseif ($this->getConfig()->getOption('cleanConditionally')) {
$this->getConfig()->setOption('cleanConditionally', false);
} else {
$parseSuccessful = false;
break;
}
} else {
break;
}
}
if (!$parseSuccessful) {
return false;
}
$result = $this->postProcessContent($result);
// Todo, fix return, check for values, maybe create a function to create the return object
return [
'title' => isset($this->metadata['title']) ? $this->metadata['title'] : null,
'author' => isset($this->metadata['author']) ? $this->metadata['author'] : null,
'image' => isset($this->metadata['image']) ? $this->metadata['image'] : null,
'images' => $this->getImages(),
'article' => $result,
'html' => $result->C14N(),
'dir' => isset($this->metadata['articleDir']) ? $this->metadata['articleDir'] : null,
];
}
/**
* Creates a DOM Document object and loads the provided HTML on it.
*
* Used for the first load of Readability and subsequent reloads (when disabling flags and rescanning the text)
* Previous versions of Readability used this method one time and cloned the DOM to keep a backup. This caused bugs
* because cloning the DOM object keeps a relation between the clone and the original one, doing changes in both
* objects and ruining the backup.
*
* @param string $html
*
* @return DOMDocument
*/
private function loadHTML($html)
{
$dom = new DOMDocument('1.0', 'utf-8');
$dom->registerNodeClass('DOMAttr', DOMAttr::class);
$dom->registerNodeClass('DOMCdataSection', DOMCdataSection::class);
$dom->registerNodeClass('DOMCharacterData', DOMCharacterData::class);
$dom->registerNodeClass('DOMComment', DOMComment::class);
$dom->registerNodeClass('DOMDocumentFragment', DOMDocumentFragment::class);
$dom->registerNodeClass('DOMDocumentType', DOMDocumentType::class);
$dom->registerNodeClass('DOMElement', DOMElement::class);
$dom->registerNodeClass('DOMNode', DOMNode::class);
$dom->registerNodeClass('DOMNotation', DOMNotation::class);
$dom->registerNodeClass('DOMProcessingInstruction', DOMProcessingInstruction::class);
$dom->registerNodeClass('DOMText', DOMText::class);
if (!$this->configuration->getSubstituteEntities()) {
// Keep the original HTML entities
$dom->substituteEntities = false;
}
if ($this->configuration->getNormalizeEntities()) {
// Replace UTF-8 characters with the HTML Entity equivalent. Useful to fix html with mixed content
$html = mb_convert_encoding($html, 'HTML-ENTITIES', 'UTF-8');
}
if ($this->configuration->getSummonCthulhu()) {
$html = preg_replace('/<script\b[^>]*>([\s\S]*?)<\/script>/', '', $html);
}
// Prepend the XML tag to avoid having issues with special characters. Should be harmless.
$dom->loadHTML('<?xml encoding="UTF-8">' . $html);
$dom->encoding = 'UTF-8';
$this->removeScripts($dom);
$this->prepDocument($dom);
return $dom;
}
/**
* Tries to guess relevant info from metadata of the html.
*
* @return array Metadata info. May have title, excerpt and or byline.
*/
private function getMetadata()
{
$metadata = $values = [];
// Match "description", or Twitter's "twitter:description" (Cards)
// in name attribute.
$namePattern = '/^\s*((twitter)\s*:\s*)?(description|title|image)\s*$/i';
// Match Facebook's Open Graph title & description properties.
$propertyPattern = '/^\s*og\s*:\s*(description|title|image)\s*$/i';
foreach ($this->dom->getElementsByTagName('meta') as $meta) {
/* @var DOMNode $meta */
$elementName = $meta->getAttribute('name');
$elementProperty = $meta->getAttribute('property');
if (in_array('author', [$elementName, $elementProperty])) {
$metadata['byline'] = $meta->getAttribute('content');
continue;
}
$name = null;
if (preg_match($namePattern, $elementName)) {
$name = $elementName;
} elseif (preg_match($propertyPattern, $elementProperty)) {
$name = $elementProperty;
}
if ($name) {
$content = $meta->getAttribute('content');
if ($content) {
// Convert to lowercase and remove any whitespace
// so we can match below.
$name = preg_replace('/\s/', '', strtolower($name));
$values[$name] = trim($content);
}
}
}
if (array_key_exists('description', $values)) {
$metadata['excerpt'] = $values['description'];
} elseif (array_key_exists('og:description', $values)) {
// Use facebook open graph description.
$metadata['excerpt'] = $values['og:description'];
} elseif (array_key_exists('twitter:description', $values)) {
// Use twitter cards description.
$metadata['excerpt'] = $values['twitter:description'];
}
$metadata['title'] = $this->getTitle();
if (!$metadata['title']) {
if (array_key_exists('og:title', $values)) {
// Use facebook open graph title.
$metadata['title'] = $values['og:title'];
} elseif (array_key_exists('twitter:title', $values)) {
// Use twitter cards title.
$metadata['title'] = $values['twitter:title'];
}
}
if (array_key_exists('og:image', $values) || array_key_exists('twitter:image', $values)) {
$metadata['image'] = array_key_exists('og:image', $values) ? $values['og:image'] : $values['twitter:image'];
} else {
$metadata['image'] = null;
}
return $metadata;
}
/**
* Tries to get the main article image. Will only update the metadata if the getMetadata function couldn't
* find a correct image.
*
* @return bool|string URL of the top image or false if unsuccessful.
*/
public function getMainImage()
{
$imgUrl = false;
if ($this->metadata['image'] !== null) {
$imgUrl = $this->metadata['image'];
}
if (!$imgUrl) {
foreach ($this->dom->getElementsByTagName('link') as $link) {
/** @var \DOMElement $link */
/*
* Check for the rel attribute, then check if the rel attribute is either img_src or image_src, and
* finally check for the existence of the href attribute, which should hold the image url.
*/
if ($link->hasAttribute('rel') && ($link->getAttribute('rel') === 'img_src' || $link->getAttribute('rel') === 'image_src') && $link->hasAttribute('href')) {
$imgUrl = $link->getAttribute('href');
break;
}
}
}
if (!empty($imgUrl) && $this->configuration->getFixRelativeURLs()) {
$imgUrl = $this->toAbsoluteURI($imgUrl);
}
return $imgUrl;
}
private function toAbsoluteURI($uri)
{
list($pathBase, $scheme, $prePath) = $this->getPathInfo($this->configuration->getOriginalURL());
// If this is already an absolute URI, return it.
if (preg_match('/^[a-zA-Z][a-zA-Z0-9\+\-\.]*:/', $uri)) {
return $uri;
}
// Scheme-rooted relative URI.
if (substr($uri, 0, 2) === '//') {
return $scheme . '://' . substr($uri, 2);
}
// Prepath-rooted relative URI.
if (substr($uri, 0, 1) === '/') {
return $prePath . $uri;
}
// Dotslash relative URI.
if (strpos($uri, './') === 0) {
return $pathBase . substr($uri, 2);
}
// Ignore hash URIs:
if (substr($uri, 0, 1) === '#') {
return $uri;
}
// Standard relative URI; add entire path. pathBase already includes a
// trailing "/".
return $pathBase . $uri;
}
/**
* @param string $url
*
* @return array [$pathBase, $scheme, $prePath]
*/
public function getPathInfo($url)
{
$pathBase = parse_url($url, PHP_URL_SCHEME) . '://' . parse_url($url, PHP_URL_HOST) . dirname(parse_url($url, PHP_URL_PATH)) . '/';
$scheme = parse_url($pathBase, PHP_URL_SCHEME);
$prePath = $scheme . '://' . parse_url($pathBase, PHP_URL_HOST);
return [$pathBase, $scheme, $prePath];
}
/**
* Gets nodes from the root element.
*
* @param $node DOMNode|DOMText
*
* @return array
*/
private function getNodes($node)
{
$stripUnlikelyCandidates = $this->configuration->getStripUnlikelyCandidates();
$elementsToScore = [];
/*
* First, node prepping. Trash nodes that look cruddy (like ones with the
* class name "comment", etc), and turn divs into P tags where they have been
* used inappropriately (as in, where they contain no other block level elements.)
*/
while ($node) {
$matchString = $node->getAttribute('class') . ' ' . $node->getAttribute('id');
// Remove DOMComments nodes as we don't need them and mess up children counting
if ($node->nodeTypeEqualsTo(XML_COMMENT_NODE)) {
$node = NodeUtility::removeAndGetNext($node);
continue;
}
// Check to see if this node is a byline, and remove it if it is.
if ($this->checkByline($node, $matchString)) {
$node = NodeUtility::removeAndGetNext($node);
continue;
}
// Remove unlikely candidates
if ($stripUnlikelyCandidates) {
if (
preg_match($this->regexps['unlikelyCandidates'], $matchString) &&
!preg_match($this->regexps['okMaybeItsACandidate'], $matchString) &&
!$node->tagNameEqualsTo('body') &&
!$node->tagNameEqualsTo('a')
) {
$node = NodeUtility::removeAndGetNext($node);
continue;
}
}
// Remove DIV, SECTION, and HEADER nodes without any content(e.g. text, image, video, or iframe).
if (($node->tagNameEqualsTo('div') || $node->tagNameEqualsTo('section') || $node->tagNameEqualsTo('header') ||
$node->tagNameEqualsTo('h1') || $node->tagNameEqualsTo('h2') || $node->tagNameEqualsTo('h3') ||
$node->tagNameEqualsTo('h4') || $node->tagNameEqualsTo('h5') || $node->tagNameEqualsTo('h6') ||
$node->tagNameEqualsTo('p')) &&
$node->isElementWithoutContent()) {
$node = NodeUtility::removeAndGetNext($node);
continue;
}
if (in_array(strtolower($node->nodeName), $this->defaultTagsToScore)) {
$elementsToScore[] = $node;
}
// Turn all divs that don't have children block level elements into p's
if ($node->tagNameEqualsTo('div')) {
/*
* Sites like http://mobile.slate.com encloses each paragraph with a DIV
* element. DIVs with only a P element inside and no text content can be
* safely converted into plain P elements to avoid confusing the scoring
* algorithm with DIVs with are, in practice, paragraphs.
*/
if (NodeUtility::hasSinglePNode($node)) {
$pNode = $node->getChildren(true)[0];
$node->replaceChild($pNode, $node);
$node = $pNode;
$elementsToScore[] = $node;
} elseif (!NodeUtility::hasSingleChildBlockElement($node)) {
NodeUtility::setNodeTag($node, 'p');
$elementsToScore[] = $node;
} else {
// EXPERIMENTAL
foreach ($node->getChildren() as $child) {
/** @var $child DOMNode */
if ($child->nodeType === XML_TEXT_NODE && mb_strlen(trim(NodeUtility::getTextContent($child))) > 0) {
$newNode = $node->createNode($child, 'p');
$child->replaceChild($newNode, $child);
}
}
}
}
$node = $node->getNextNode($node);
}
return $elementsToScore;
}
/**
* Checks if the node is a byline.
*
* @param DOMNode $node
* @param string $matchString
*
* @return bool
*/
private function checkByline($node, $matchString)
{
if (!$this->configuration->getArticleByLine()) {
return false;
}
/*
* Check if the byline is already set
*/
if (isset($this->metadata['byline'])) {
return false;
}
$rel = $node->getAttribute('rel');
if ($rel === 'author' || preg_match($this->regexps['byline'], $matchString) && $this->isValidByline($node->getTextContent())) {
$this->metadata['byline'] = trim($node->getTextContent());
return true;
}
return false;
}
/**
* Checks the validity of a byLine. Based on string length.
*
* @param string $text
*
* @return bool
*/
private function isValidByline($text)
{
if (gettype($text) == 'string') {
$byline = trim($text);
return (mb_strlen($byline) > 0) && (mb_strlen($text) < 100);
}
return false;
}
/**
* Removes all the scripts of the html.
*
* @param DOMDocument $dom
*/
private function removeScripts(DOMDocument $dom)
{
$toRemove = ['script', 'noscript'];
foreach ($toRemove as $tag) {
while ($script = $dom->getElementsByTagName($tag)) {
if ($script->item(0)) {
$script->item(0)->parentNode->removeChild($script->item(0));
} else {
break;
}
}
}
}
/**
* Prepares the document for parsing.
*
* @param DOMDocument $dom
*/
private function prepDocument(DOMDocument $dom)
{
/*
* DOMNodeList must be converted to an array before looping over it.
* This is done to avoid node shifting when removing nodes.
*
* Reverse traversing cannot be done here because we need to find brs that are right next to other brs.
* (If we go the other way around we need to search for previous nodes forcing the creation of new functions
* that will be used only here)
*/
foreach (iterator_to_array($dom->getElementsByTagName('br')) as $br) {
$next = $br->nextSibling;
/*
* Whether 2 or more <br> elements have been found and replaced with a
* <p> block.
*/
$replaced = false;
/*
* If we find a <br> chain, remove the <br>s until we hit another element
* or non-whitespace. This leaves behind the first <br> in the chain
* (which will be replaced with a <p> later).
*/
while (($next = NodeUtility::nextElement($next)) && ($next->nodeName === 'br')) {
$replaced = true;
$brSibling = $next->nextSibling;
$next->parentNode->removeChild($next);
$next = $brSibling;
}
/*
* If we removed a <br> chain, replace the remaining <br> with a <p>. Add
* all sibling nodes as children of the <p> until we hit another <br>
* chain.
*/
if ($replaced) {
$p = $dom->createElement('p');
$br->parentNode->replaceChild($p, $br);
$next = $p->nextSibling;
while ($next) {
// If we've hit another <br><br>, we're done adding children to this <p>.
if ($next->nodeName === 'br') {
$nextElem = NodeUtility::nextElement($next);
if ($nextElem && $nextElem->nodeName === 'br') {
break;
}
}
// Otherwise, make this node a child of the new <p>.
$sibling = $next->nextSibling;
$p->appendChild($next);
$next = $sibling;
}
}
}
// Replace font tags with span
$fonts = $dom->getElementsByTagName('font');
$length = $fonts->length;
for ($i = 0; $i < $length; $i++) {
$font = $fonts->item($length - 1 - $i);
NodeUtility::setNodeTag($font, 'span', true);
}
}
/**
* @return null|string
*/
public function __toString()
{
return $this->getContent();
}
/**
* @return string|null
*/
public function getTitle()
{
return $this->title;
}
/**
* @param null $title
*/
protected function setTitle($title)
{
$this->title = $title;
}
/**
* @return string|null
*/
public function getContent()
{
return $this->content;
}
/**
* @param null $content
*/
protected function setContent($content)
{
$this->content = $content;
}
/**
* @return string|null
*/
public function getImage()
{
return $this->image;
}
/**
* @param null $image
*/
protected function setImage($image)
{
$this->image = $image;
}
/**
* @return string|null
*/
public function getAuthor()
{
return $this->author;
}
/**
* @param null $author
*/
protected function setAuthor($author)
{
$this->author = $author;
}
}
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