<?php
/**
* @package Regular Labs Library
* @version 23.12.10783
*
* @author Peter van Westen <[email protected]>
* @link https://regularlabs.com
* @copyright Copyright © 2023 Regular Labs All Rights Reserved
* @license GNU General Public License version 2 or later
*/
namespace RegularLabs\Library;
defined('_JEXEC') or die;
use DOMDocument;
class Html
{
/**
* Removes complete html tag pairs from the concatenated parts
*/
public static function cleanSurroundingTags(
array $parts,
array $elements = ['p', 'span']
): array
{
$breaks = '(?:(?:<br ?/?>|<\!--[^>]*-->|:\|:)\s*)*';
$keys = array_keys($parts);
$string = implode(':|:', $parts);
Protect::protectHtmlCommentTags($string);
// Remove empty tags
$regex = '<(' . implode('|', $elements) . ')(?: [^>]*)?>\s*(' . $breaks . ')<\/\1>\s*';
while (RegEx::match($regex, $string, $match))
{
$string = str_replace($match[0], $match[2], $string);
}
// Remove paragraphs around block elements
$block_elements = [
'p', 'div',
'table', 'tr', 'td', 'thead', 'tfoot',
'h[1-6]',
];
$block_elements = '(' . implode('|', $block_elements) . ')';
$regex = '(<p(?: [^>]*)?>)(\s*' . $breaks . ')(<' . $block_elements . '(?: [^>]*)?>)';
while (RegEx::match($regex, $string, $match))
{
if ($match[4] == 'p')
{
$match[3] = $match[1] . $match[3];
self::combinePTags($match[3]);
}
$string = str_replace($match[0], $match[2] . $match[3], $string);
}
$regex = '(</' . $block_elements . '>\s*' . $breaks . ')</p>';
while (RegEx::match($regex, $string, $match))
{
$string = str_replace($match[0], $match[1], $string);
}
Protect::unprotect($string);
$parts = explode(':|:', $string);
$new_tags = [];
foreach ($parts as $key => $val)
{
$key = $keys[$key] ?? $key;
$new_tags[$key] = $val;
}
return $new_tags;
}
/**
* Combine duplicate <p> tags
* input: <p class="aaa" a="1"><!-- ... --><p class="bbb" b="2">
* output: <p class="aaa bbb" a="1" b="2"><!-- ... -->
*/
public static function combinePTags(string &$string): void
{
if (empty($string))
{
return;
}
$p_start_tag = '<p(?: [^>]*)?>';
$optional_tags = '\s*(?:<\!--[^>]*-->| |&\#160;)*\s*';
Protect::protectHtmlCommentTags($string);
RegEx::matchAll('(' . $p_start_tag . ')(' . $optional_tags . ')(' . $p_start_tag . ')', $string, $tags);
if (empty($tags))
{
Protect::unprotect($string);
return;
}
foreach ($tags as $tag)
{
$string = str_replace($tag[0], $tag[2] . HtmlTag::combine($tag[1], $tag[3]), $string);
}
Protect::unprotect($string);
}
/**
* Check if string contains block elements
*/
public static function containsBlockElements(string $string): string
{
return RegEx::match('</?(' . implode('|', self::getBlockElements()) . ')(?: [^>]*)?>', $string);
}
/**
* Convert content saved in a WYSIWYG editor to plain text (like removing html tags)
*/
public static function convertWysiwygToPlainText(string $string): string
{
// replace chr style enters with normal enters
$string = str_replace([chr(194) . chr(160), ' ', ' '], ' ', $string);
// replace linebreak tags with normal linebreaks (paragraphs, enters, etc).
$enter_tags = ['p', 'br'];
$regex = '</?((' . implode(')|(', $enter_tags) . '))+[^>]*?>\n?';
$string = RegEx::replace($regex, " \n", $string);
// replace indent characters with spaces
$string = RegEx::replace('<img [^>]*/sourcerer/images/tab\.png[^>]*>', ' ', $string);
// strip all other tags
$regex = '<(/?\w+((\s+\w+(\s*=\s*(?:".*?"|\'.*?\'|[^\'">\s]+))?)+\s*|\s*)/?)>';
$string = RegEx::replace($regex, '', $string);
// reset htmlentities
$string = StringHelper::html_entity_decoder($string);
// convert protected html entities &_...; -> &...;
$string = RegEx::replace('&_([a-z0-9\#]+?);', '&\1;', $string);
return $string;
}
/**
* Fix broken/invalid html syntax in a string
*/
public static function fix(string $string): string
{
if ( ! self::containsBlockElements($string))
{
return $string;
}
// Convert utf8 characters to html entities
if (function_exists('mb_decode_numericentity'))
{
$string = mb_encode_numericentity($string, [0x80, 0xffff, 0, ~0], 'UTF-8');
}
$string = self::protectSpecialCode($string);
$string = self::convertDivsInsideInlineElementsToSpans($string);
$string = self::removeParagraphsAroundBlockElements($string);
$string = self::removeInlineElementsAroundBlockElements($string);
$string = self::fixParagraphsAroundParagraphElements($string);
$string = class_exists('DOMDocument')
? self::fixUsingDOMDocument($string)
: self::fixUsingCustomFixer($string);
$string = self::unprotectSpecialCode($string);
// Convert html entities back to utf8 characters
if (function_exists('mb_decode_numericentity'))
{
$string = mb_decode_numericentity($string, [0x80, 0xffff, 0, ~0], 'UTF-8');
}
$string = self::removeParagraphsAroundComments($string);
return $string;
}
/**
* Fix broken/invalid html syntax in an array of strings
*/
public static function fixArray(array $array): array
{
$splitter = ':|:';
$string = self::fix(implode($splitter, $array));
$parts = self::removeEmptyTags(explode($splitter, $string));
// use original keys but new values
return array_combine(array_keys($array), $parts);
}
/**
* Return an array of block element names, optionally without any of the names given $exclude
*/
public static function getBlockElements(array $exclude = []): array
{
if ( ! is_array($exclude))
{
$exclude = [$exclude];
}
$elements = [
'div', 'p', 'pre',
'h1', 'h2', 'h3', 'h4', 'h5', 'h6',
];
$elements = array_diff($elements, $exclude);
$elements = implode(',', $elements);
$elements = str_replace('h1,h2,h3,h4,h5,h6', 'h[1-6]', $elements);
$elements = explode(',', $elements);
return $elements;
}
/**
* Return an array of block element names, without divs and any of the names given $exclude
*/
public static function getBlockElementsNoDiv(array $exclude = []): array
{
return array_diff(self::getBlockElements($exclude), ['div']);
}
/**
* Extract the <body>...</body> part from an entire html output string
*/
public static function getBody(string $html, bool $include_body_tag = true): array
{
if ( ! str_contains($html, '<body') || ! str_contains($html, '</body>'))
{
return ['', $html, ''];
}
// Force string to UTF-8
$html = StringHelper::convertToUtf8($html);
$split = explode('<body', $html, 2);
$pre = $split[0];
$split = explode('>', $split[1], 2);
$body_start = '<body' . $split[0] . '>';
$body_end = '</body>';
$split = explode('</body>', $split[1]);
$post = array_pop($split);
$body = implode('</body>', $split);
if ( ! $include_body_tag)
{
return [
$pre . $body_start,
$body,
$body_end . $post,
];
}
return [
$pre,
$body_start . $body . $body_end,
$post,
];
}
/**
* Search the string for the start and end searches and split the string in a pre, body and post part
* This is used to be able to do replacements on the body part, which will be lighter than doing it on the entire string
*/
public static function getContentContainingSearches(
string $string,
array $start_searches = [],
array $end_searches = [],
int $start_offset = 1000,
?int $end_offset = null
): array
{
// String is too short to split and search through
if (strlen($string) < 2000)
{
return ['', $string, ''];
}
$end_offset = is_null($end_offset) ? $start_offset : $end_offset;
$found = false;
$start_split = strlen($string);
foreach ($start_searches as $search)
{
$pos = strpos($string, $search);
if ($pos === false)
{
continue;
}
$start_split = min($start_split, $pos);
$found = true;
}
// No searches are found
if ( ! $found)
{
return [$string, '', ''];
}
// String is too short to split
if (strlen($string) < ($start_offset + $end_offset + 1000))
{
return ['', $string, ''];
}
$start_split = max($start_split - $start_offset, 0);
$pre = substr($string, 0, $start_split);
$string = substr($string, $start_split);
self::fixBrokenTagsByPreString($pre, $string);
if (empty($end_searches))
{
$end_searches = $start_searches;
}
$end_split = 0;
$found = false;
foreach ($end_searches as $search)
{
$pos = strrpos($string, $search);
if ($pos === false)
{
continue;
}
$end_split = max($end_split, $pos + strlen($search));
$found = true;
}
// No end split is found, so don't split remainder
if ( ! $found)
{
return [$pre, $string, ''];
}
$end_split = min($end_split + $end_offset, strlen($string));
$post = substr($string, $end_split);
$string = substr($string, 0, $end_split);
self::fixBrokenTagsByPostString($post, $string);
return [$pre, $string, $post];
}
/**
* Return an array of inline element names, optionally without any of the names given $exclude
*/
public static function getInlineElements(array $exclude = []): array
{
if ( ! is_array($exclude))
{
$exclude = [$exclude];
}
$elements = [
'span', 'code', 'a',
'strong', 'b', 'em', 'i', 'u', 'big', 'small', 'font',
'sup', 'sub',
];
return array_diff($elements, $exclude);
}
/**
* Return an array of block element names, without anchors (a) and any of the names given $exclude
*/
public static function getInlineElementsNoAnchor(array $exclude = []): array
{
return array_diff(self::getInlineElements($exclude), ['a']);
}
/**
* Remove empty tags
*/
public static function removeEmptyTagPairs(
string $string,
array $elements = ['p', 'span']
): string
{
$breaks = '(?:(?:<br ?/?>|<\!--[^>]*-->)\s*)*';
$regex = '<(' . implode('|', $elements) . ')(?: [^>]*)?>\s*(' . $breaks . ')<\/\1>\s*';
Protect::protectHtmlCommentTags($string);
while (RegEx::match($regex, $string, $match))
{
$string = str_replace($match[0], $match[2], $string);
}
Protect::unprotect($string);
return $string;
}
/**
* Removes empty tags which span concatenating parts in the array
*/
public static function removeEmptyTags(array $array): array
{
$splitter = ':|:';
$comments = '(?:\s*<\!--[^>]*-->\s*)*';
$string = implode($splitter, $array);
Protect::protectHtmlCommentTags($string);
$string = RegEx::replace(
'<([a-z][a-z0-9]*)(?: [^>]*)?>\s*(' . $comments . RegEx::quote($splitter) . $comments . ')\s*</\1>',
'\2',
$string
);
Protect::unprotect($string);
return explode($splitter, $string);
}
/**
* Removes html tags from string
*/
public static function removeHtmlTags(string $string, bool $remove_comments = false): string
{
// remove pagenavcounter
$string = RegEx::replace('<div class="pagenavcounter">.*?</div>', ' ', $string);
// remove pagenavbar
$string = RegEx::replace('<div class="pagenavbar">(<div>.*?</div>)*</div>', ' ', $string);
// remove inline scripts
$string = RegEx::replace('<script[^a-z0-9].*?</script>', '', $string);
$string = RegEx::replace('<noscript[^a-z0-9].*?</noscript>', '', $string);
// remove inline styles
$string = RegEx::replace('<style[^a-z0-9].*?</style>', '', $string);
// remove inline html tags
$string = RegEx::replace(
'</?(' . implode('|', self::getInlineElements()) . ')( [^>]*)?>',
'',
$string
);
if ($remove_comments)
{
// remove html comments
$string = RegEx::replace('<!--.*?-->', ' ', $string);
}
// replace other tags with a space
$string = RegEx::replace('</?[a-z].*?>', ' ', $string);
// remove double whitespace
$string = trim(RegEx::replace('(\s)[ ]+', '\1', $string));
return $string;
}
/**
* Remove inline elements around block elements
*/
public static function removeInlineElementsAroundBlockElements(string $string): string
{
$string = RegEx::replace(
'(?:<(?:' . implode('|', self::getInlineElementsNoAnchor()) . ')(?: [^>]*)?>\s*)'
. '(</?(?:' . implode('|', self::getBlockElements()) . ')(?: [^>]*)?>)',
'\1',
$string
);
$string = RegEx::replace(
'(</?(?:' . implode('|', self::getBlockElements()) . ')(?: [^>]*)?>)'
. '(?:\s*</(?:' . implode('|', self::getInlineElementsNoAnchor()) . ')>)',
'\1',
$string
);
return $string;
}
/**
* Convert <div> tags inside inline elements to <span> tags
*/
private static function convertDivsInsideInlineElementsToSpans(string $string): string
{
if ( ! str_contains($string, '</div>'))
{
return $string;
}
// Ignore block elements inside anchors
$regex = '<(' . implode('|', self::getInlineElementsNoAnchor()) . ')(?: [^>]*)?>.*?</\1>';
RegEx::matchAll($regex, $string, $matches, '', PREG_PATTERN_ORDER);
if (empty($matches))
{
return $string;
}
$matches = array_unique($matches[0]);
$searches = [];
$replacements = [];
foreach ($matches as $match)
{
if ( ! str_contains($match, '</div>'))
{
continue;
}
$searches[] = $match;
$replacements[] = str_replace(
['<div>', '<div ', '</div>'],
['<span>', '<span ', '</span>'],
$match
);
}
if (empty($searches))
{
return $string;
}
return str_replace($searches, $replacements, $string);
}
/**
* Prevents broken html tags at the beginning of $pre (other half at end of $string)
* It will move the broken part to the end of $string to complete it
*/
private static function fixBrokenTagsByPostString(string &$post, string &$string): void
{
if ( ! RegEx::match('<(\![^>]*|/?[a-z][^>]*(="[^"]*)?)$', $string, $match))
{
return;
}
if ( ! RegEx::match('^[^>]*>', $post, $match))
{
return;
}
$post = substr($post, strlen($match[0]));
$string .= $match[0];
}
/**
* Prevents broken html tags at the end of $pre (other half at beginning of $string)
* It will move the broken part to the beginning of $string to complete it
*/
private static function fixBrokenTagsByPreString(string &$pre, string &$string): void
{
if ( ! RegEx::match('<(\![^>]*|/?[a-z][^>]*(="[^"]*)?)$', $pre, $match))
{
return;
}
$pre = substr($pre, 0, strlen($pre) - strlen($match[0]));
$string = $match[0] . $string;
}
/**
* Fix <p> tags around other <p> elements
*/
private static function fixParagraphsAroundParagraphElements(string $string): string
{
if ( ! str_contains($string, '</p>'))
{
return $string;
}
$parts = explode('</p>', $string);
$ending = '</p>' . array_pop($parts);
foreach ($parts as &$part)
{
if ( ! str_contains($part, '<p>') && ! str_contains($part, '<p '))
{
$part = '<p>' . $part;
continue;
}
$part = RegEx::replace(
'(<p(?: [^>]*)?>.*?)(<p(?: [^>]*)?>)',
'\1</p>\2',
$part
);
}
return implode('</p>', $parts) . $ending;
}
/**
* Fix broken/invalid html syntax in a string using custom code as an alternative to php DOMDocument functionality
*/
private static function fixUsingCustomFixer(string $string): string
{
$block_regex = '<(' . implode('|', self::getBlockElementsNoDiv()) . ')[\s>]';
$string = RegEx::replace('(' . $block_regex . ')', '[:SPLIT-BLOCK:]\1', $string);
$parts = explode('[:SPLIT-BLOCK:]', $string);
foreach ($parts as $i => &$part)
{
if ( ! RegEx::match('^' . $block_regex, $part, $type))
{
continue;
}
$type = strtolower($type[1]);
// remove endings of other block elements
$part = RegEx::replace('</(?:' . implode('|', self::getBlockElementsNoDiv($type)) . ')>', '', $part);
if (str_contains($part, '</' . $type . '>'))
{
continue;
}
// Add ending tag once
$part = RegEx::replaceOnce('(\s*)$', '</' . $type . '>\1', $part);
// Remove empty block tags
$part = RegEx::replace('^<' . $type . '(?: [^>]*)?>\s*</' . $type . '>', '', $part);
}
return implode('', $parts);
}
/**
* Fix broken/invalid html syntax in a string using php DOMDocument functionality
*/
private static function fixUsingDOMDocument(string $string): string
{
$doc = new DOMDocument;
$doc->substituteEntities = false;
[$pre, $body, $post] = Html::getBody($string, false);
// Add temporary document structures
$body = '<html><body><div>' . $body . '</div></body></html>';
@$doc->loadHTML($body);
$body = $doc->saveHTML();
if (str_contains($doc->documentElement->textContent, 'Ã'))
{
// Need to do this utf8 workaround to deal with special characters
// DOMDocument doesn't seem to deal with them very well
// See: https://stackoverflow.com/questions/8218230/php-domdocument-loadhtml-not-encoding-utf-8-correctly/47396055#47396055
$body = StringHelper::utf8_decode($doc->saveHTML($doc->documentElement));
}
// Remove temporary document structures and surrounding div
$body = RegEx::replace('^.*?<html>.*?(?:<head>(.*)</head>.*?)?<body>\s*<div>(.*)</div>\s*</body>.*?$', '\1\2', $body);
// Remove leading/trailing empty paragraph
$body = RegEx::replace('(^\s*<div>\s*</div>|<div>\s*</div>\s*$)', '', $body);
// Remove leading/trailing empty paragraph
$body = RegEx::replace('(^\s*<div>\s*</div>|<div>\s*</div>\s*$)', '', $body);
// Remove leading/trailing empty paragraph
$body = RegEx::replace('(^\s*<p(?: [^>]*)?>\s*</p>|<p(?: [^>]*)?>\s*</p>\s*$)', '', $body);
return $pre . $body . $post;
}
/**
* Protect plugin style tags and php
*/
private static function protectSpecialCode(string $string): string
{
// Protect PHP code
Protect::protectByRegex($string, '(<|<)\?php\s.*?\?(>|>)');
// Protect {...} tags
Protect::protectByRegex($string, '\{[a-z0-9].*?\}');
// Protect [...] tags
Protect::protectByRegex($string, '\[[a-z0-9].*?\]');
// Protect scripts
Protect::protectByRegex($string, '<script[^>]*>.*?</script>');
// Protect css
Protect::protectByRegex($string, '<style[^>]*>.*?</style>');
Protect::convertProtectionToHtmlSafe($string);
return $string;
}
/**
* Remove <p> tags around block elements
*/
private static function removeParagraphsAroundBlockElements(string $string): string
{
if ( ! str_contains($string, '</p>'))
{
return $string;
}
Protect::protectHtmlCommentTags($string);
$string = RegEx::replace(
'<p(?: [^>]*)?>\s*'
. '((?:<\!--[^>]*-->\s*)*</?(?:' . implode('|', self::getBlockElements()) . ')' . '(?: [^>]*)?>)',
'\1',
$string
);
$string = RegEx::replace(
'(</?(?:' . implode('|', self::getBlockElements()) . ')' . '(?: [^>]*)?>(?:\s*<\!--[^>]*-->)*)'
. '(?:\s*</p>)',
'\1',
$string
);
Protect::unprotect($string);
return $string;
}
/**
* Remove <p> tags around comments
*/
private static function removeParagraphsAroundComments(string $string): string
{
if ( ! str_contains($string, '</p>'))
{
return $string;
}
Protect::protectHtmlCommentTags($string);
$string = RegEx::replace(
'(?:<p(?: [^>]*)?>\s*)'
. '(<\!--[^>]*-->)'
. '(?:\s*</p>)',
'\1',
$string
);
Protect::unprotect($string);
return $string;
}
/**
* Unprotect protected tags
*/
private static function unprotectSpecialCode(string $string): string
{
Protect::unprotectHtmlSafe($string);
return $string;
}
}