Habari\Format::autop PHP Method

    public static function autop($value)
    {
        $value = str_replace("\r\n", "\n", $value);
        $value = trim($value);
        $ht = new HtmlTokenizer($value, false);
        $set = $ht->parse();
        $value = '';
        // should never autop ANY content in these items
        $no_auto_p = array('pre', 'code', 'ul', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'object', 'applet', 'embed', 'table', 'ul', 'ol', 'li', 'i', 'b', 'em', 'strong', 'script', 'dl', 'dt', 'dd');
        $block_elements = array('address', 'blockquote', 'center', 'dir', 'div', 'dl', 'fieldset', 'form', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr', 'isindex', 'menu', 'noframes', 'object', 'applet', 'embed', 'noscript', 'ol', 'p', 'pre', 'table', 'ul', 'figure', 'figcaption');
        $token = $set->current();
        // There are no tokens in the text being formatted
        if ($token === false) {
            return $value;
        }
        $open_p = false;
        do {
            if ($open_p) {
                if (($token['type'] == HTMLTokenizer::NODE_TYPE_ELEMENT_EMPTY || $token['type'] == HTMLTokenizer::NODE_TYPE_ELEMENT_OPEN || $token['type'] == HTMLTokenizer::NODE_TYPE_ELEMENT_CLOSE) && in_array(strtolower($token['name']), $block_elements)) {
                    if (strtolower($token['name']) != 'p' || $token['type'] != HTMLTokenizer::NODE_TYPE_ELEMENT_CLOSE) {
                        $value .= '</p>';
                    }
                    $open_p = false;
                }
            }
            if (($token['type'] == HTMLTokenizer::NODE_TYPE_ELEMENT_OPEN || $token['type'] == HTMLTokenizer::NODE_TYPE_ELEMENT_EMPTY) && !in_array(strtolower($token['name']), $block_elements) && !$open_p) {
                // first element, is not a block element
                $value .= '<p>';
                $open_p = true;
            }
            // no-autop, pass them through verbatim
            if ($token['type'] == HTMLTokenizer::NODE_TYPE_ELEMENT_OPEN && in_array(strtolower($token['name']), $no_auto_p)) {
                $nested_token = $token;
                do {
                    $value .= HtmlTokenSet::token_to_string($nested_token, false);
                    if ($nested_token['type'] == HTMLTokenizer::NODE_TYPE_ELEMENT_CLOSE && strtolower($nested_token['name']) == strtolower($token['name'])) {
                        break;
                    }
                } while ($nested_token = $set->next());
                continue;
            }
            // anything that's not a text node should get passed through
            if ($token['type'] != HTMLTokenizer::NODE_TYPE_TEXT) {
                $value .= HtmlTokenSet::token_to_string($token, true);
                // If the token itself is p, we need to set $open_p
                if (strtolower($token['name']) == 'p' && $token['type'] == HTMLTokenizer::NODE_TYPE_ELEMENT_OPEN) {
                    $open_p = true;
                }
                continue;
            }
            // if we get this far, token type is text
            $local_value = $token['value'];
            if (MultiByte::strlen($local_value)) {
                if (!$open_p) {
                    $local_value = '<p>' . ltrim($local_value);
                    $open_p = true;
                }
                $local_value = preg_replace('/\\s*(\\n\\s*){2,}/u', "</p><p>", $local_value);
                // at least two \n in a row (allow whitespace in between)
                $local_value = str_replace("\n", "<br>", $local_value);
                // nl2br
            }
            $value .= $local_value;
        } while ($token = $set->next());
        $value = preg_replace('#\\s*<p></p>\\s*#u', '', $value);
        // replace <p></p>
        $value = preg_replace('/<p><!--(.*?)--><\\/p>/', "<!--\\1-->", $value);
        // replace <p></p> around comments
        if ($open_p) {
            $value .= '</p>';
        }
        return $value;
    }