Small PHP function to prevent orphans from occurring in digital typography. More on orphans, widows, and rags: http://www.fonts.com/content/learning/fontology/level-2/text-typography/rags-widows-orphans

no_orphans.php

<?php
// What are orphans?
// http://www.fonts.com/content/learning/fontology/level-2/text-typography/rags-widows-orphans
function noOrphans($str) {
  $nbspStr = null;
  if (strpos($str, '<p>') !== false) {
    $paragraphs = explode('</p>', $str);
    foreach($paragraphs as &$paragraph) {
      $lastSpace = strrpos($paragraph, ' ');
      $nbspParagraph = substr_replace($paragraph, '<span class="nbsp">&nbsp;</span>', $lastSpace, 1);
      $nbspParagraph = $nbspParagraph . '</p>';
      $paragraph = $nbspParagraph;
    }
    $nbspParagraphs = implode($paragraphs);
    return $nbspParagraphs;
  }
  else {
    $lastSpace = strrpos($str, ' ');
    $nbspStr = substr_replace($str, '<span class="nbsp">&nbsp;</span>', $lastSpace, 1);
  }
  return $nbspStr;
};
?>