app/Util/HtmlDocument.php
<?php
namespace BookStack\Util;
use DOMDocument;
use DOMElement;
use DOMNode;
use DOMNodeList;
use DOMXPath;
/**
* HtmlDocument is a thin wrapper around DOMDocument built
* specifically for loading, querying and generating HTML content.
*/
class HtmlDocument
{
protected DOMDocument $document;
protected ?DOMXPath $xpath = null;
protected int $loadOptions;
public function __construct(string $partialHtml = '', int $loadOptions = 0)
{
libxml_use_internal_errors(true);
$this->document = new DOMDocument();
$this->loadOptions = $loadOptions;
if ($partialHtml) {
$this->loadPartialHtml($partialHtml);
}
}
/**
* Load some HTML content that's part of a document (e.g. body content)
* into the current document.
*/
public function loadPartialHtml(string $html): void
{
$html = '<?xml encoding="utf-8" ?><body>' . $html . '</body>';
$this->document->loadHTML($html, $this->loadOptions);
$this->xpath = null;
}
/**
* Load a complete page of HTML content into the document.
*/
public function loadCompleteHtml(string $html): void
{
$html = '<?xml encoding="utf-8" ?>' . $html;
$this->document->loadHTML($html, $this->loadOptions);
$this->xpath = null;
}
/**
* Start an XPath query on the current document.
*/
public function queryXPath(string $expression): DOMNodeList
{
if (is_null($this->xpath)) {
$this->xpath = new DOMXPath($this->document);
}
$result = $this->xpath->query($expression);
if ($result === false) {
throw new \InvalidArgumentException("XPath query for expression [$expression] failed to execute");
}
return $result;
}
/**
* Create a new DOMElement instance within the document.
*/
public function createElement(string $localName, string $value = ''): DOMElement
{
$element = $this->document->createElement($localName, $value);
if ($element === false) {
throw new \InvalidArgumentException("Failed to create element of name [$localName] and value [$value]");
}
return $element;
}
/**
* Get an element within the document of the given ID.
*/
public function getElementById(string $elementId): ?DOMElement
{
return $this->document->getElementById($elementId);
}
/**
* Get the DOMNode that represents the HTML body.
*/
public function getBody(): DOMNode
{
return $this->document->getElementsByTagName('body')[0];
}
/**
* Get the nodes that are a direct child of the body.
* This is usually all the content nodes if loaded partially.
*/
public function getBodyChildren(): DOMNodeList
{
return $this->getBody()->childNodes;
}
/**
* Get the inner HTML content of the body.
* This is usually all the content if loaded partially.
*/
public function getBodyInnerHtml(): string
{
$html = '';
foreach ($this->getBodyChildren() as $child) {
$html .= $this->document->saveHTML($child);
}
return $html;
}
/**
* Get the HTML content of the whole document.
*/
public function getHtml(): string
{
return $this->document->saveHTML($this->document->documentElement);
}
/**
* Get the inner HTML for the given node.
*/
public function getNodeInnerHtml(DOMNode $node): string
{
$html = '';
foreach ($node->childNodes as $childNode) {
$html .= $this->document->saveHTML($childNode);
}
return $html;
}
/**
* Get the outer HTML for the given node.
*/
public function getNodeOuterHtml(DOMNode $node): string
{
return $this->document->saveHTML($node);
}
}