Ip\Internal\Text\Html2Text::iterate_over_node PHP Метод

    protected static function iterate_over_node($node)
    {
        if ($node instanceof \DOMText) {
            return mb_ereg_replace("/[\\t\\n\\v\\f\\r ]+/im", " ", $node->wholeText);
        }
        if ($node instanceof \DOMDocumentType) {
            // ignore
            return "";
        }
        $nextName = self::next_child_name($node);
        $prevName = self::prev_child_name($node);
        $name = mb_strtolower($node->nodeName);
        // start whitespace
        switch ($name) {
            case "hr":
                return "------\n";
            case "style":
            case "head":
            case "title":
            case "meta":
            case "script":
                // ignore these tags
                return "";
            case "h1":
            case "h2":
            case "h3":
            case "h4":
            case "h5":
            case "h6":
                // add two newlines
                $output = "\n";
                break;
            case "p":
            case "div":
                // add one line
                $output = "\n";
                break;
            default:
                // print out contents of unknown tags
                $output = "";
                break;
        }
        // debug
        //$output .= "[$name,$nextName]";
        if (isset($node->childNodes)) {
            for ($i = 0; $i < $node->childNodes->length; $i++) {
                $n = $node->childNodes->item($i);
                $text = self::iterate_over_node($n);
                $output .= $text;
            }
        }
        // end whitespace
        switch ($name) {
            case "style":
            case "head":
            case "title":
            case "meta":
            case "script":
                // ignore these tags
                return "";
            case "h1":
            case "h2":
            case "h3":
            case "h4":
            case "h5":
            case "h6":
                $output .= "\n";
                break;
            case "p":
            case "br":
                // add one line
                if ($nextName != "div") {
                    $output .= "\n";
                }
                break;
            case "div":
                // add one line only if the next child isn't a div
                if ($nextName != "div" && $nextName != null) {
                    $output .= "\n";
                }
                break;
            case "a":
                // links are returned in [text](link) format
                $href = $node->getAttribute("href");
                if ($href == null) {
                    // it doesn't link anywhere
                    if ($node->getAttribute("name") != null) {
                        $output = "[{$output}]";
                    }
                } else {
                    if ($href == $output || $href == "mailto:{$output}" || $href == "http://{$output}" || $href == "https://{$output}") {
                        // link to the same address: just use link
                        $output;
                    } else {
                        // replace it
                        $output = "[{$output}]({$href})";
                    }
                }
                // does the next node require additional whitespace?
                switch ($nextName) {
                    case "h1":
                    case "h2":
                    case "h3":
                    case "h4":
                    case "h5":
                    case "h6":
                        $output .= "\n";
                        break;
                }
            default:
                // do nothing
        }
        return $output;
    }