上面的方案还是有局限性的,因为有些 HTML 标签是成对出现的。如果摘录包含一个开始标签但没有相应的结束标签,那么网页的其余部分很可能格式不正确。
此代码检查此类标签的摘录并根据需要添加结束标签:
<?php
/******************************************************************************
* @Author: Richard Chonak
* @Date: August 6, 2013
* @Description: Ensures closure of HTML tags opened in an automatically generated excerpt.
* Also trims off any trailing incomplete HTML tag at the end of the excerpt.
* @Tested: Up to WordPress version 3.6
*
* @Author: Boutros AbiChedid
* @Date: June 20, 2011
* @Websites: http://bacsoftwareconsulting.com/ ; http://blueoliveonline.com/
* @Description: Preserves HTML formating to the automatically generated Excerpt.
* Also Code modifies the default excerpt_length and excerpt_more filters.
* @Tested: Up to WordPress version 3.1.3
*******************************************************************************/
function custom_wp_trim_excerpt($text) {
$raw_excerpt = $text;
if ( '' == $text ) {
//Retrieve the post content.
$text = get_the_content('');
//Delete all shortcode tags from the content.
$text = strip_shortcodes( $text );
$text = apply_filters('the_content', $text);
$text = str_replace(']]>', ']]>', $text);
$allowed_tags = '<img>,<small>,<strong>,<em>,<b>,<i>,<p>,<br>,<a>,<blockquote>,<ul>,<li>'; /*** MODIFY THIS. Add the allowed HTML tags separated by a comma.***/
$twopart_tags = '<small>,<strong>,<em>,<b>,<i>,<p>,<br>,<a>,<blockquote>,<ul>,<li>'; /*** MODIFY THIS. Add the twopart HTML tags separated by a comma.***/
/* turn tag list into one big search pattern */
$search_patterns = "/" . str_replace(",","|",str_replace(">", "[^>]*>",$twopart_tags)) . '/';
$text = strip_tags($text, $allowed_tags);
$excerpt_word_count = 200; /*** MODIFY THIS. change the excerpt word count to any integer you like.***/
$excerpt_length = apply_filters('excerpt_length', $excerpt_word_count);
$excerpt_end = '[...]'; /*** MODIFY THIS. change the excerpt endind to something else.***/
$excerpt_more = apply_filters('excerpt_more', ' ' . $excerpt_end);
$words = preg_split("/[\n\r\t ]+/", $text, $excerpt_length + 1, PREG_SPLIT_NO_EMPTY);
if ( count($words) > $excerpt_length ) {
array_pop($words);
$text = implode(' ', $words);
$text = $text . $excerpt_more;
} else {
$text = implode(' ', $words);
};
/* if fragment ends in open tag, trim off */
preg_replace ("/<[^>]*$/", "", $text);
/* search for tags in excerpt */
preg_match_all ($search_patterns, $text, $matches);
/* if any tags found, check for matching pairs */
$tagstack = array ("");
$tagsfound = $matches[0];
while ( count ($tagsfound) > 0) {
$tagmatch = array_shift($tagsfound);
/* if it's a closing tag, hooray; but if it's not, then look for the closer */
if ( !strpos($tagmatch,"</") && !strpos ($tagmatch,"/>") ) {
preg_match("/\pL+/",$tagmatch, $tagwords);
$endtag = "</" . $tagwords[0] . ">";
/* if this tag was not closed, put the closing tag on the stack */
if (!in_array($endtag, $tagsfound) ) {
array_push($tagstack,$endtag);
};
};
};
/* if any unbalanced tags were found, add the closing tags */
while (count ($tagstack) > 1) {
$text = $text . array_pop($tagstack);
}
}
return apply_filters('wp_trim_excerpt', $text, $raw_excerpt);
}
remove_filter('get_the_excerpt', 'wp_trim_excerpt');
add_filter('get_the_excerpt', 'custom_wp_trim_excerpt');
?>