preventWidows.php

<?php

// Prevent Widows Kirby CMS plugin

// Makes line breaking text go from:
//   Lorem ipsum dolor sit amet, consectetur adipiscing
//   elit.
// To:
//   Lorem ipsum dolor sit amet, consectetur
//   adipiscing elit.

// Put in your site/plugins folder

field::$methods['kirbytext'] = field::$methods['kt'] = function($field) {
    // Adds &nbsp; char before second to last word
    // Regex from http://www.webmastertools.bz/simple-php-regex-script-to-prevent-orphans-in-paragraph-text/
    $textNoWidows = preg_replace('/\s([\w]+[.,!\:;\\"-?]{0,1})$/', '&nbsp;\\1', $field->value);

    // Runs kirbytext like normal
    $field->value = kirbytext($textNoWidows);
    return $field;
};