[Contextual Search Results in WordPress] #wordpress #php

contextual-search-results-in-wordpress.md

Contextual Search Results in WordPress

Created: 2017.04.09

A solution from Hacking at 0300

x-contextual-search-results-in-wordpress.php

function query_re(){
 global $wp_query;
 $terms = $wp_query->query_vars['search_terms'];
 foreach ($terms as &$term) $term = preg_quote($term, '/');
  return '/'.implode('|', $terms).'/iu';
}

add_filter('the_excerpt', function ($text){
  return preg_replace_text (query_re(), '<span class="searchterm">$0</span>', $text);
});

remove_all_filters('get_the_excerpt'); // we want to take over handling the excerpt
add_filter( 'get_the_excerpt', function($excerpt){
 global $post;
 $excerpt_length = apply_filters('excerpt_length', 55);
  $excerpt_more = apply_filters('excerpt_more', '…');
 $query_re =  query_re();
  
  // First choice: the author-composed excerpt
  if ($excerpt &amp;&amp; preg_match($query_re, $excerpt)) return $excerpt;

 // Second choice: the start of the text
 // get the actual text of the post
  $text = wp_strip_all_tags(apply_filters('the_content', $post-&gt;post_content));
  // Create the default excerpt
 $excerpted_text = wp_trim_words($text, $excerpt_length, $excerpt_more);
 if (preg_match($query_re, $excerpted_text)) return $excerpted_text;
 
  // Third choice: context of the search term
 $text_matched = preg_match ($query_re, $text, $matches, PREG_OFFSET_CAPTURE); // save the matched terms with their offsets
  if ($text_matched){
   $offset = $matches[0][1]+strlen($matches[0][0]); // the offset into the end of the text where the term was found
    // hack: we want to add context for where the term was found, but we want it to use whole words. wp_trim_words will trim the end,
   // but we want so many words (empirically, one third the excerpt length) in the beginning. So we reverse the text and use that.
   $len = $excerpt_length/3;
   // need to use a single character to indicate truncation since we are reversing the text
    $reversetext = strrev_utf8(wp_trim_words(strrev_utf8(substr($text, 0, $offset)), $len, '…'));
   $context = $reversetext.substr($text, $offset); // rebuild it
   return wp_trim_words($context, $excerpt_length, $excerpt_more);
 }
 
  // No matches. Just use the usual excerpt 
  return $excerpt ? $excerpt : $excerpted_text;
});