Doctrine\OXM\Marshaller\XmlMarshaller::doMarshal PHP Method

    private function doMarshal($mappedObject, WriterHelper $writer)
    {
        $className = get_class($mappedObject);
        $classMetadata = $this->classMetadataFactory->getMetadataFor($className);
        if (!$this->classMetadataFactory->hasMetadataFor($className)) {
            throw MarshallerException::mappingNotFoundForClass($className);
        }
        // PreMarshall Hook
        if ($classMetadata->hasLifecycleCallbacks(Events::preMarshal)) {
            $classMetadata->invokeLifecycleCallbacks(Events::preMarshal, $mappedObject);
        }
        if (isset($this->visited[spl_object_hash($mappedObject)])) {
            return;
        }
        $this->visited[spl_object_hash($mappedObject)] = true;
        $writer->startElement($classMetadata->getXmlName());
        $namespaces = $classMetadata->getXmlNamespaces();
        if (!empty($namespaces)) {
            foreach ($namespaces as $namespace) {
                $writer->writeNamespace($namespace['url'], $namespace['prefix']);
            }
        }
        // build ordered field mappings for this class
        $fieldMappings = $classMetadata->getFieldMappings();
        $orderedMap = array();
        if (!empty($fieldMappings)) {
            foreach ($fieldMappings as $fieldMapping) {
                $orderedMap[$fieldMapping['node']][] = $fieldMapping;
            }
        }
        // do attributes
        if (array_key_exists(ClassMetadata::XML_ATTRIBUTE, $orderedMap)) {
            foreach ($orderedMap[ClassMetadata::XML_ATTRIBUTE] as $fieldMapping) {
                $fieldName = $fieldMapping['fieldName'];
                $fieldValue = $classMetadata->getFieldValue($mappedObject, $fieldName);
                if ($classMetadata->isRequired($fieldName) && $fieldValue === null) {
                    throw MarshallerException::fieldRequired($className, $fieldName);
                }
                if ($fieldValue !== null || $classMetadata->isNullable($fieldName)) {
                    $this->writeAttribute($writer, $classMetadata, $fieldName, $fieldValue);
                }
            }
        }
        // do text
        if (array_key_exists(ClassMetadata::XML_TEXT, $orderedMap)) {
            foreach ($orderedMap[ClassMetadata::XML_TEXT] as $fieldMapping) {
                $fieldName = $fieldMapping['fieldName'];
                $fieldValue = $classMetadata->getFieldValue($mappedObject, $fieldName);
                if ($classMetadata->isRequired($fieldName) && $fieldValue === null) {
                    throw MarshallerException::fieldRequired($className, $fieldName);
                }
                if ($fieldValue !== null || $classMetadata->isNullable($fieldName)) {
                    $this->writeText($writer, $classMetadata, $fieldName, $fieldValue);
                }
            }
        }
        // do elements
        if (array_key_exists(ClassMetadata::XML_ELEMENT, $orderedMap)) {
            foreach ($orderedMap[ClassMetadata::XML_ELEMENT] as $fieldMapping) {
                $fieldName = $fieldMapping['fieldName'];
                $fieldValue = $classMetadata->getFieldValue($mappedObject, $fieldName);
                if ($classMetadata->isRequired($fieldName) && $fieldValue === null) {
                    throw MarshallerException::fieldRequired($className, $fieldName);
                }
                if ($fieldValue !== null || $classMetadata->isNullable($fieldName)) {
                    $this->writeElement($writer, $classMetadata, $fieldName, $fieldValue);
                }
            }
        }
        // do value
        if (array_key_exists(ClassMetadata::XML_VALUE, $orderedMap)) {
            foreach ($orderedMap[ClassMetadata::XML_VALUE] as $fieldMapping) {
                $fieldName = $fieldMapping['fieldName'];
                $fieldValue = $classMetadata->getFieldValue($mappedObject, $fieldName);
                if ($classMetadata->isRequired($fieldName) && $fieldValue === null) {
                    throw MarshallerException::fieldRequired($className, $fieldName);
                }
                if ($fieldValue !== null || $classMetadata->isNullable($fieldName)) {
                    $type = $classMetadata->getTypeOfField($fieldName);
                    $writer->writeValue(Type::getType($type)->convertToXmlValue($fieldValue));
                }
            }
        }
        // PostMarshal hook
        if ($classMetadata->hasLifecycleCallbacks(Events::postMarshal)) {
            $classMetadata->invokeLifecycleCallbacks(Events::postMarshal, $mappedObject);
        }
        $writer->endElement();
    }