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<?php
namespace andreskrey\Readability;
use League\HTMLToMarkdown\Element;
/**
* Class DOMElement.
*
* This is a extension of the original Element class from League\HTMLToMarkdown\Element.
* This class adds functions specific to Readability.php and overloads some of them to fit the purpose of this project.
*/
class Readability extends Element implements ReadabilityInterface
{
/**
* @var \DOMNode
*/
protected $node;
/**
* @var int
*/
protected $contentScore = 0;
/**
* @var int
*/
protected $initialized = false;
/**
* @var array
*/
private $regexps = [
'positive' => '/article|body|content|entry|hentry|h-entry|main|page|pagination|post|text|blog|story/i',
'negative' => '/hidden|^hid$| hid$| hid |^hid |banner|combx|comment|com-|contact|foot|footer|footnote|masthead|media|meta|modal|outbrain|promo|related|scroll|share|shoutbox|sidebar|skyscraper|sponsor|shopping|tags|tool|widget/i',
];
/**
* Constructor.
*
* @param \DOMNode $node Selected element from DOMDocument
*/
public function __construct(\DOMNode $node)
{
parent::__construct($node);
/*
* Restore the score if the object has been already scored.
*
* An if must be added before calling the getAttribute function, because if we reach the DOMDocument
* by getting the node parents we'll get a undefined function fatal error
*/
$score = 0;
// Check if the getAttribute method exists, as some elements lack of it (and calling it anyway throws an exception)
if (method_exists($node, 'getAttribute')) {
if ($node->hasAttribute('data-readability')) {
// Node was initialized previously. Restoring score and setting flag.
$this->initialized = true;
$score = $node->getAttribute('data-readability');
$this->setContentScore($score);
}
}
}
/**
* Checks for the tag name. Case insensitive.
*
* @param string $value Name to compare to the current tag
*
* @return bool
*/
public function tagNameEqualsTo($value)
{
$tagName = $this->getTagName();
if (strtolower($value) === strtolower($tagName)) {
return true;
}
return false;
}
/**
* Get the ancestors of the current node.
*
* @param int $maxLevel Max amount of ancestors to get.
*
* @return array
*/
public function getNodeAncestors($maxLevel = 3)
{
$ancestors = [];
$level = 0;
$node = $this->getParent();
while ($node) {
$ancestors[] = $node;
$level++;
if ($level >= $maxLevel) {
break;
}
$node = $node->getParent();
}
return $ancestors;
}
/**
* Overloading the getParent function from League\HTMLToMarkdown\Element due to a bug when there are no more parents
* on the selected element.
*
* @return Readability|null
*/
public function getParent()
{
$node = $this->node->parentNode;
return ($node) ? new self($node) : null;
}
/**
* Returns all links from the current element.
*
* @return array|null
*/
public function getAllLinks()
{
if (($this->isText())) {
return null;
} else {
$links = [];
foreach ($this->node->getElementsByTagName('a') as $link) {
$links[] = new self($link);
}
return $links;
}
}
/**
* Initializer. Calculates the current score of the node and returns a full Readability object.
*
* @return Readability
*/
public function initializeNode()
{
if (!$this->initialized) {
$contentScore = 0;
switch ($this->getTagName()) {
case 'div':
$contentScore += 5;
break;
case 'pre':
case 'td':
case 'blockquote':
$contentScore += 3;
break;
case 'address':
case 'ol':
case 'ul':
case 'dl':
case 'dd':
case 'dt':
case 'li':
case 'form':
$contentScore -= 3;
break;
case 'h1':
case 'h2':
case 'h3':
case 'h4':
case 'h5':
case 'h6':
case 'th':
$contentScore -= 5;
break;
}
$this->setContentScore($contentScore + $this->getClassWeight());
$this->initialized = true;
}
return $this;
}
/**
* Calculates the weight of the class/id of the current element.
*
* @todo check for flag that lets this function run or not
*
* @return int
*/
public function getClassWeight()
{
// TODO To implement. How to get config from html parser from readability
// if ($this->getConfig()->getOption('weightClasses')) {
// return 0;
// }
//
$weight = 0;
// Look for a special classname
$class = $this->getAttribute('class');
if (trim($class)) {
if (preg_match($this->regexps['negative'], $class)) {
$weight -= 25;
}
if (preg_match($this->regexps['positive'], $class)) {
$weight += 25;
}
}
// Look for a special ID
$id = $this->getAttribute('id');
if (trim($id)) {
if (preg_match($this->regexps['negative'], $id)) {
$weight -= 25;
}
if (preg_match($this->regexps['positive'], $id)) {
$weight += 25;
}
}
return $weight;
}
/**
* Returns the current score of the Readability object.
*
* @return int
*/
public function getContentScore()
{
return $this->contentScore;
}
/**
* Returns the current score of the Readability object.
*
* @param int $score
*
* @return int
*/
public function setContentScore($score)
{
// Check if the setAttribute method exists, as some elements lack of it (and calling it anyway throws an exception)
if (method_exists($this->node, 'setAttribute')) {
$this->contentScore = (float)$score;
// Set score in an attribute of the tag to prevent losing it while creating new Readability objects.
$this->node->setAttribute('data-readability', $this->contentScore);
return $this->contentScore;
}
return 0;
}
/**
* Returns the full text of the node.
*
* @param bool $normalize Normalize white space?
*
* @return string
*/
public function getTextContent($normalize = false)
{
$nodeValue = $this->node->nodeValue;
if ($normalize) {
$nodeValue = trim(preg_replace('/\s{2,}/', ' ', $nodeValue));
}
return $nodeValue;
}
/**
* Changes the node tag name. Since tagName on DOMElement is a read only value, this must be done creating a new
* element with the new tag name and importing it to the main DOMDocument
*
* @param string $value
*/
public function setNodeTag($value)
{
$new = new \DOMDocument();
$new->appendChild($new->createElement($value));
$childs = $this->node->childNodes;
for ($i = 0; $i < $childs->length; $i++) {
$import = $new->importNode($childs->item($i), true);
$new->firstChild->appendChild($import);
}
// The import must be done on the firstChild of $new, since $new is a DOMDocument and not a DOMElement.
$import = $this->node->ownerDocument->importNode($new->firstChild, true);
$this->node->parentNode->replaceChild($import, $this->node);
$this->node = $import;
}
/**
* Returns the current DOMNode.
*
* @return \DOMNode
*/
public function getDOMNode()
{
return $this->node;
}
/**
* Removes the current node and returns the next node to be parsed (child, sibling or parent)
*
* @param Readability $node
*
* @return Readability
*/
public function removeAndGetNext($node)
{
$nextNode = $this->getNextNode($node, true);
$node->node->parentNode->removeChild($node->node);
return $nextNode;
}
/**
* Returns the next node. First checks for childs (if the flag allows it), then for siblings, and finally
* for parents.
*
* @param Readability $originalNode
* @param bool $ignoreSelfAndKids
*
* @return Readability
*/
public function getNextNode($originalNode, $ignoreSelfAndKids = false)
{
/*
* Traverse the DOM from node to node, starting at the node passed in.
* Pass true for the second parameter to indicate this node itself
* (and its kids) are going away, and we want the next node over.
*
* Calling this in a loop will traverse the DOM depth-first.
*/
// First check for kids if those aren't being ignored
if (!$ignoreSelfAndKids && $originalNode->node->firstChild) {
return new self($originalNode->node->firstChild);
}
// Then for siblings...
if ($originalNode->node->nextSibling) {
return new self($originalNode->node->nextSibling);
}
// And finally, move up the parent chain *and* find a sibling
// (because this is depth-first traversal, we will have already
// seen the parent nodes themselves).
do {
$originalNode = $originalNode->getParent();
} while ($originalNode && !$originalNode->node->nextSibling);
return ($originalNode) ? new self($originalNode->node->nextSibling) : $originalNode;
}
/**
* Compares nodes. Checks for tag name and text content.
*
* It's a replacement of the original JS code, which looked like this:
*
* $node1 == $node2
*
* I'm not sure this works the same in PHP, so I created a mock function to check the actual content of the node.
* Should serve the same porpuse as the original comparison.
*
* @param Readability $node1
* @param Readability $node2
*
* @return bool
*/
public function compareNodes($node1, $node2)
{
if ($node1->getTagName() !== $node2->getTagName()) {
return false;
}
if ($node1->getTextContent(true) !== $node2->getTextContent(true)) {
return false;
}
return true;
}
/**
* Replaces child node with a new one.
*
* @param Readability $newNode
*
*/
public function replaceChild(Readability $newNode)
{
$this->node->parentNode->replaceChild($newNode->node, $this->node);
}
/**
* Creates a new node based on the text content of the original node.
*
* @param Readability $originalNode
* @param string $tagName
*
* @return Readability
*/
public function createNode(Readability $originalNode, $tagName)
{
$text = $originalNode->getTextContent();
$newNode = $originalNode->node->ownerDocument->createElement($tagName, $text);
return new static($newNode);
}
/**
* Checks if the object is initialized.
*
* @return bool
*/
public function isInitialized()
{
return $this->initialized;
}
/**
* Reloads the score stores in the data-readability tag.
*
* @return int|bool
*/
public function reloadScore()
{
if (method_exists($this->node, 'getAttribute')) {
if ($this->node->hasAttribute('data-readability')) {
$this->initialized = true;
$score = $this->node->getAttribute('data-readability');
$this->setContentScore($score);
return $score;
}
}
return false;
}
/**
* Check if a given node has one of its ancestor tag name matching the
* provided one.
*
* @param Readability $node
* @param string $tagName
* @param int $maxDepth
* @return bool
*/
public function hasAncestorTag(Readability $node, $tagName, $maxDepth = 3)
{
$depth = 0;
while ($node->getParent()) {
if ($depth > $maxDepth) {
return false;
}
if ($node->getParent()->tagNameEqualsTo($tagName)) {
return true;
}
$node = $node->getParent();
$depth++;
}
return false;
}
/**
* @param bool $filterEmptyDOMText Filter empty DOMText nodes?
* @return array
*/
public function getChildren($filterEmptyDOMText = false)
{
$ret = array();
/** @var \DOMNode $node */
foreach ($this->node->childNodes as $node) {
if ($filterEmptyDOMText && $node->nodeName === '#text' && !trim($node->nodeValue)) {
continue;
}
$ret[] = new static($node);
}
return $ret;
}
}
|