(PHP 5, PHP 7)
DOMDocument::createAttributeNS — Create new attribute node with an associated namespace
This function creates a new instance of class DOMAttr. This node will not show up in the document unless it is inserted with (e.g.) DOMNode::appendChild().
namespaceURIThe URI of the namespace.
qualifiedNameThe tag name and prefix of the attribute, as prefix:tagname.
   The new DOMAttr or FALSE if an error occurred.
  
DOM_INVALID_CHARACTER_ERR
       Raised if qualifiedName contains an invalid character.
      
DOM_NAMESPACE_ERR
       Raised if qualifiedName is a malformed qualified
       name, or if qualifiedName has a prefix and 
       namespaceURI is NULL.