arrayToXml.php

/**
 * Note: Also removes anything after the _ in the key. Useful for
 * adding nodes with the same name. e.g. Node_1 and Node_2 both become Node.
 * Appends child to argument by reference.
 * @param array $element
 * @param \SimpleXMLElement $parent
 * @return \SimpleXMLElement
 */
protected function arrayToXml (array $element, \SimpleXMLElement $parent) {
    foreach ($element as $key => $child) {
        // Removes text after first _
        $key = explode('_', $key)[0];

        if (is_array($child)) {
            $this->arrayToXml($child, $parent->addChild($key));
        } else {
            $parent->addChild($key, $child);
        }
    }
}