SAML2\Assertion::addAttributeStatement PHP Method

    private function addAttributeStatement(\DOMElement $root)
    {
        if (empty($this->attributes)) {
            return;
        }
        $document = $root->ownerDocument;
        $attributeStatement = $document->createElementNS(Constants::NS_SAML, 'saml:AttributeStatement');
        $root->appendChild($attributeStatement);
        foreach ($this->attributes as $name => $values) {
            $attribute = $document->createElementNS(Constants::NS_SAML, 'saml:Attribute');
            $attributeStatement->appendChild($attribute);
            $attribute->setAttribute('Name', $name);
            if ($this->nameFormat !== Constants::NAMEFORMAT_UNSPECIFIED) {
                $attribute->setAttribute('NameFormat', $this->nameFormat);
            }
            // make sure eduPersonTargetedID can be handled properly as a NameID
            if ($name === Constants::EPTI_URN_MACE || $name === Constants::EPTI_URN_OID) {
                foreach ($values as $eptiValue) {
                    $attributeValue = $document->createElementNS(Constants::NS_SAML, 'saml:AttributeValue');
                    $attribute->appendChild($attributeValue);
                    if ($eptiValue instanceof XML\saml\NameID) {
                        $eptiValue->toXML($attributeValue);
                    } elseif ($eptiValue instanceof \DOMNodeList) {
                        $node = $root->ownerDocument->importNode($eptiValue->item(0), true);
                        $attributeValue->appendChild($node);
                    } else {
                        $attributeValue->textContent = $eptiValue;
                    }
                }
                continue;
            }
            foreach ($values as $value) {
                if (is_string($value)) {
                    $type = 'xs:string';
                } elseif (is_int($value)) {
                    $type = 'xs:integer';
                } else {
                    $type = null;
                }
                $attributeValue = $document->createElementNS(Constants::NS_SAML, 'saml:AttributeValue');
                $attribute->appendChild($attributeValue);
                if ($type !== null) {
                    $attributeValue->setAttributeNS(Constants::NS_XSI, 'xsi:type', $type);
                }
                if (is_null($value)) {
                    $attributeValue->setAttributeNS(Constants::NS_XSI, 'xsi:nil', 'true');
                }
                if ($value instanceof \DOMNodeList) {
                    for ($i = 0; $i < $value->length; $i++) {
                        $node = $document->importNode($value->item($i), true);
                        $attributeValue->appendChild($node);
                    }
                } else {
                    $attributeValue->appendChild($document->createTextNode($value));
                }
            }
        }
    }