WordPress Version: 6.4
/**
* Replaces double line breaks with paragraph elements.
*
* A group of regex replaces used to identify text formatted with newlines and
* replace double line breaks with HTML paragraph tags. The remaining line breaks
* after conversion become `<br />` tags, unless `$br` is set to '0' or 'false'.
*
* @since 0.71
*
* @param string $text The text which has to be formatted.
* @param bool $br Optional. If set, this will convert all remaining line breaks
* after paragraphing. Line breaks within `<script>`, `<style>`,
* and `<svg>` tags are not affected. Default true.
* @return string Text which has been converted into correct paragraph tags.
*/
function wpautop($text, $br = true)
{
$pre_tags = array();
if (trim($text) === '') {
return '';
}
// Just to make things a little easier, pad the end.
$text = $text . "\n";
/*
* Pre tags shouldn't be touched by autop.
* Replace pre tags with placeholders and bring them back after autop.
*/
if (str_contains($text, '<pre')) {
$text_parts = explode('</pre>', $text);
$last_part = array_pop($text_parts);
$text = '';
$i = 0;
foreach ($text_parts as $text_part) {
$start = strpos($text_part, '<pre');
// Malformed HTML?
if (false === $start) {
$text .= $text_part;
continue;
}
$name = "<pre wp-pre-tag-{$i}></pre>";
$pre_tags[$name] = substr($text_part, $start) . '</pre>';
$text .= substr($text_part, 0, $start) . $name;
++$i;
}
$text .= $last_part;
}
// Change multiple <br>'s into two line breaks, which will turn into paragraphs.
$text = preg_replace('|<br\s*/?>\s*<br\s*/?>|', "\n\n", $text);
$allblocks = '(?:table|thead|tfoot|caption|col|colgroup|tbody|tr|td|th|div|dl|dd|dt|ul|ol|li|pre|form|map|area|blockquote|address|style|p|h[1-6]|hr|fieldset|legend|section|article|aside|hgroup|header|footer|nav|figure|figcaption|details|menu|summary)';
// Add a double line break above block-level opening tags.
$text = preg_replace('!(<' . $allblocks . '[\s/>])!', "\n\n\$1", $text);
// Add a double line break below block-level closing tags.
$text = preg_replace('!(</' . $allblocks . '>)!', "\$1\n\n", $text);
// Add a double line break after hr tags, which are self closing.
$text = preg_replace('!(<hr\s*?/?>)!', "\$1\n\n", $text);
// Standardize newline characters to "\n".
$text = str_replace(array("\r\n", "\r"), "\n", $text);
// Find newlines in all elements and add placeholders.
$text = wp_replace_in_html_tags($text, array("\n" => ' <!-- wpnl --> '));
// Collapse line breaks before and after <option> elements so they don't get autop'd.
if (str_contains($text, '<option')) {
$text = preg_replace('|\s*<option|', '<option', $text);
$text = preg_replace('|</option>\s*|', '</option>', $text);
}
/*
* Collapse line breaks inside <object> elements, before <param> and <embed> elements
* so they don't get autop'd.
*/
if (str_contains($text, '</object>')) {
$text = preg_replace('|(<object[^>]*>)\s*|', '$1', $text);
$text = preg_replace('|\s*</object>|', '</object>', $text);
$text = preg_replace('%\s*(</?(?:param|embed)[^>]*>)\s*%', '$1', $text);
}
/*
* Collapse line breaks inside <audio> and <video> elements,
* before and after <source> and <track> elements.
*/
if (str_contains($text, '<source') || str_contains($text, '<track')) {
$text = preg_replace('%([<\[](?:audio|video)[^>\]]*[>\]])\s*%', '$1', $text);
$text = preg_replace('%\s*([<\[]/(?:audio|video)[>\]])%', '$1', $text);
$text = preg_replace('%\s*(<(?:source|track)[^>]*>)\s*%', '$1', $text);
}
// Collapse line breaks before and after <figcaption> elements.
if (str_contains($text, '<figcaption')) {
$text = preg_replace('|\s*(<figcaption[^>]*>)|', '$1', $text);
$text = preg_replace('|</figcaption>\s*|', '</figcaption>', $text);
}
// Remove more than two contiguous line breaks.
$text = preg_replace("/\n\n+/", "\n\n", $text);
// Split up the contents into an array of strings, separated by double line breaks.
$paragraphs = preg_split('/\n\s*\n/', $text, -1, PREG_SPLIT_NO_EMPTY);
// Reset $text prior to rebuilding.
$text = '';
// Rebuild the content as a string, wrapping every bit with a <p>.
foreach ($paragraphs as $paragraph) {
$text .= '<p>' . trim($paragraph, "\n") . "</p>\n";
}
// Under certain strange conditions it could create a P of entirely whitespace.
$text = preg_replace('|<p>\s*</p>|', '', $text);
// Add a closing <p> inside <div>, <address>, or <form> tag if missing.
$text = preg_replace('!<p>([^<]+)</(div|address|form)>!', '<p>$1</p></$2>', $text);
// If an opening or closing block element tag is wrapped in a <p>, unwrap it.
$text = preg_replace('!<p>\s*(</?' . $allblocks . '[^>]*>)\s*</p>!', '$1', $text);
// In some cases <li> may get wrapped in <p>, fix them.
$text = preg_replace('|<p>(<li.+?)</p>|', '$1', $text);
// If a <blockquote> is wrapped with a <p>, move it inside the <blockquote>.
$text = preg_replace('|<p><blockquote([^>]*)>|i', '<blockquote$1><p>', $text);
$text = str_replace('</blockquote></p>', '</p></blockquote>', $text);
// If an opening or closing block element tag is preceded by an opening <p> tag, remove it.
$text = preg_replace('!<p>\s*(</?' . $allblocks . '[^>]*>)!', '$1', $text);
// If an opening or closing block element tag is followed by a closing <p> tag, remove it.
$text = preg_replace('!(</?' . $allblocks . '[^>]*>)\s*</p>!', '$1', $text);
// Optionally insert line breaks.
if ($br) {
// Replace newlines that shouldn't be touched with a placeholder.
$text = preg_replace_callback('/<(script|style|svg|math).*?<\/\1>/s', '_autop_newline_preservation_helper', $text);
// Normalize <br>
$text = str_replace(array('<br>', '<br/>'), '<br />', $text);
// Replace any new line characters that aren't preceded by a <br /> with a <br />.
$text = preg_replace('|(?<!<br />)\s*\n|', "<br />\n", $text);
// Replace newline placeholders with newlines.
$text = str_replace('<WPPreserveNewline />', "\n", $text);
}
// If a <br /> tag is after an opening or closing block tag, remove it.
$text = preg_replace('!(</?' . $allblocks . '[^>]*>)\s*<br />!', '$1', $text);
// If a <br /> tag is before a subset of opening or closing block tags, remove it.
$text = preg_replace('!<br />(\s*</?(?:p|li|div|dl|dd|dt|th|pre|td|ul|ol)[^>]*>)!', '$1', $text);
$text = preg_replace("|\n</p>\$|", '</p>', $text);
// Replace placeholder <pre> tags with their original content.
if (!empty($pre_tags)) {
$text = str_replace(array_keys($pre_tags), array_values($pre_tags), $text);
}
// Restore newlines in all elements.
if (str_contains($text, '<!-- wpnl -->')) {
$text = str_replace(array(' <!-- wpnl --> ', '<!-- wpnl -->'), "\n", $text);
}
return $text;
}