Generate an Excerpt from given content. Strips off html tags and preserves word boundaries

generateExcerpt.php

<?php
echo generateExcerpt('Some long text is not really present here', 15);   // Some long...

/**
* Generate an Excerpt for a given String
* @param string $content The content
* @param int $maxLength The maximum length of the desired excerpt
* @param string $more the string to use as more
* @return string
*/
function generateExcerpt($content = null, $maxLength = 300, $more = '...') {
    if (empty($content)) return '';
    $excerpt = strip_tags(trim(preg_replace('/\s+/', ' ', $content)));
    $maxLength = $maxLength - strlen($more);
    if (strlen($excerpt) > $maxLength) {
        $excerpt = substr($excerpt, 0, $maxLength);             // strip the text to the desired length
        $excerpt = substr($excerpt, 0, strrpos($excerpt, " ")); // get last space character to preserve word boundaries
        $excerpt = $excerpt . $more;                            // concatenate 'more' text
    }
    return $excerpt;
}