The DOMXPath object doesn't create a reference to the document. If you load a new xml using either load, loadXML or loadHTML functions the DOMXPath object will still query and evaluate over the source in the DOMDocument when it was created.
Crea un nuevo objeto DOMXPath.
document
El objeto DOMDocument asociado con el objeto DOMXPath.
registerNodeNS
Whether to automatically register the in-scope namespace prefixes of the context node to the DOMXPath object. This can be used to avoid needing to call DOMXPath::registerNamespace() manually for each in-scope namespaces. When a namespace prefix conflict exists, only the nearest descendant namespace prefix is registered.
The DOMXPath object doesn't create a reference to the document. If you load a new xml using either load, loadXML or loadHTML functions the DOMXPath object will still query and evaluate over the source in the DOMDocument when it was created.