mtv\wp\models\Post::make_excerpt PHP Method

    public function make_excerpt($more_text = null)
    {
        // Author inserted a <!--more--> tag
        $parts = get_extended($this->post_content);
        if (!empty($parts['extended'])) {
            $ret = trim($parts['main']);
            // Conditionally add a read more link and
            // clean up punctuation and ellipsis at end of excerpt
            $wc_excerpt = str_word_count($ret);
            $wc_content = str_word_count($this->post_content);
            if ($wc_excerpt < $wc_content) {
                $ret = preg_replace('/([\\.,;:!?\'"]{4,})$/', '...', $ret . '...');
                if (!empty($more_text)) {
                    $ret = $ret . ' <a href="' . $this->permalink . '" class="more-link">' . $more_text . '</a>';
                }
            }
        }
        // Excerpt is empty, so generate one
        if (empty($parts['extended'])) {
            $text = strip_shortcodes($this->post_content);
            $text = apply_filters('the_content', $text);
            $text = str_replace(']]>', ']]&gt;', $text);
            $text = strip_tags($text);
            $excerpt_length = apply_filters('excerpt_length', 55);
            $read_more = apply_filters('read_more', ' ' . '[...]', $this);
            $words = preg_split("/[\n\r\t ]+/", $text, $excerpt_length + 1, PREG_SPLIT_NO_EMPTY);
            if (count($words) > $excerpt_length) {
                array_pop($words);
                $text = implode(' ', $words);
                $text = $text . $read_more;
            } else {
                $text = implode(' ', $words);
            }
            $ret = apply_filters('wp_trim_excerpt', $text, $raw_excerpt);
        }
        /* TODO: cache results of this function */
        return $ret;
    }