Kirby plugin to truncate by number of words and preserve tags. Works with Kirby v2.

truncate.php

<?php
  function truncate($input, $numwords, $padding="")
  {
    $output = strtok($input, " \n");
    while(--$numwords > 0) $output .= " " . strtok(" \n");
    if($output != $input) $output .= $padding;
      // Original PHP code by Chirp Internet: www.chirp.com.au
      // Please acknowledge use of this code by including this header.

    $opened = array();

    // loop through opened and closed tags in order
    if(preg_match_all("/<(\/?[a-z]+)>?/i", $output, $matches)) {
      foreach($matches[1] as $tag) {
        if(preg_match("/^[a-z]+$/i", $tag, $regs)) {
          // a tag has been opened
          if(strtolower($regs[0]) != 'br') $opened[] = $regs[0];
        } elseif(preg_match("/^\/([a-z]+)$/i", $tag, $regs)) {
          // a tag has been closed
          $array_keys = array_keys($opened, $regs[1]);
          unset($opened[array_pop($array_keys)]);
        }
      }
    }

    // close tags that are still open
    if($opened) {
      $tagstoclose = array_reverse($opened);
      foreach($tagstoclose as $tag) $output .= "</$tag>";
    }

    return $output;
  }
?>