XML_Serializer::_createXMLTag PHP Method

    function _createXMLTag($tag, $firstCall = true)
    {
        // build fully qualified tag name
        if ($this->options[XML_SERIALIZER_OPTION_NAMESPACE] !== null) {
            if (is_array($this->options[XML_SERIALIZER_OPTION_NAMESPACE])) {
                $tag['qname'] = $this->options[XML_SERIALIZER_OPTION_NAMESPACE][0] . ':' . $tag['qname'];
            } else {
                $tag['qname'] = $this->options[XML_SERIALIZER_OPTION_NAMESPACE] . ':' . $tag['qname'];
            }
        }
        // attribute indentation
        if ($this->options[XML_SERIALIZER_OPTION_INDENT_ATTRIBUTES] !== false) {
            $multiline = true;
            $indent = str_repeat($this->options[XML_SERIALIZER_OPTION_INDENT], $this->_tagDepth);
            if ($this->options[XML_SERIALIZER_OPTION_INDENT_ATTRIBUTES] == '_auto') {
                $indent .= str_repeat(' ', strlen($tag['qname']) + 2);
            } else {
                $indent .= $this->options[XML_SERIALIZER_OPTION_INDENT_ATTRIBUTES];
            }
        } else {
            $multiline = false;
            $indent = false;
        }
        if (is_array($tag['content'])) {
            if (empty($tag['content'])) {
                $tag['content'] = '';
            }
        } elseif (XML_SERIALIZER_OPTION_FALSE_AS_STRING && $tag['content'] === false) {
            $tag['content'] = '0';
        } elseif (is_scalar($tag['content']) && (string) $tag['content'] == '') {
            $tag['content'] = '';
        }
        // replace XML entities
        if ($firstCall === true) {
            if ($this->options[XML_SERIALIZER_OPTION_CDATA_SECTIONS] === true) {
                $replaceEntities = XML_UTIL_CDATA_SECTION;
            } else {
                $replaceEntities = $this->options[XML_SERIALIZER_OPTION_ENTITIES];
            }
        } else {
            // this is a nested call, so value is already encoded
            // and must not be encoded again
            $replaceEntities = XML_SERIALIZER_ENTITIES_NONE;
            // but attributes need to be encoded anyways
            // (done here because the rest of the code assumes the same encoding
            // can be used both for attributes and content)
            foreach ($tag['attributes'] as $k => $v) {
                $v = XML_Util::replaceEntities($v, $this->options[XML_SERIALIZER_OPTION_ENTITIES]);
                $tag['attributes'][$k] = $v;
            }
        }
        if (is_scalar($tag['content']) || is_null($tag['content'])) {
            if ($this->options[XML_SERIALIZER_OPTION_ENCODE_FUNC]) {
                if ($firstCall === true) {
                    $tag['content'] = call_user_func($this->options[XML_SERIALIZER_OPTION_ENCODE_FUNC], $tag['content']);
                }
                $tag['attributes'] = array_map($this->options[XML_SERIALIZER_OPTION_ENCODE_FUNC], $tag['attributes']);
            }
            $tag = XML_Util::createTagFromArray($tag, $replaceEntities, $multiline, $indent, $this->options[XML_SERIALIZER_OPTION_LINEBREAKS]);
        } elseif (is_array($tag['content'])) {
            $tag = $this->_serializeArray($tag['content'], $tag['qname'], $tag['attributes']);
        } elseif (is_object($tag['content'])) {
            $tag = $this->_serializeObject($tag['content'], $tag['qname'], $tag['attributes']);
        } elseif (is_resource($tag['content'])) {
            settype($tag['content'], 'string');
            if ($this->options[XML_SERIALIZER_OPTION_ENCODE_FUNC]) {
                if ($replaceEntities === true) {
                    $tag['content'] = call_user_func($this->options[XML_SERIALIZER_OPTION_ENCODE_FUNC], $tag['content']);
                }
                $tag['attributes'] = array_map($this->options[XML_SERIALIZER_OPTION_ENCODE_FUNC], $tag['attributes']);
            }
            $tag = XML_Util::createTagFromArray($tag, $replaceEntities);
        }
        return $tag;
    }