PHP: retrieve all declared namespaces of a DOMElement
问题 I am using the DOM extension to parse an xml file containing xml namespaces. I would have thought that namespace declarations are treated just like any other attribute, but my tests seem to disagree. I have a document that starts like this: <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns="http://purl.org/rss/1.0/" xmlns:taxo="http://purl.org/rss/1.0/modules/taxonomy/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:syn="http://purl.org/rss/1.0/modules/syndication/"