xform_instance_parser.py 文件源码

def get_meta_from_xml(xml_str, meta_name):
    xml = clean_and_parse_xml(xml_str)
    children = xml.childNodes
    # children ideally contains a single element
    # that is the parent of all survey elements
    if children.length == 0:
        raise ValueError(_("XML string must have a survey element."))
    survey_node = children[0]
    meta_tags = [n for n in survey_node.childNodes if
                 n.nodeType == Node.ELEMENT_NODE and
                 (n.tagName.lower() == "meta" or
                     n.tagName.lower() == "orx:meta")]
    if len(meta_tags) == 0:
        return None

    # get the requested tag
    meta_tag = meta_tags[0]
    uuid_tags = [n for n in meta_tag.childNodes if
                 n.nodeType == Node.ELEMENT_NODE and
                 (n.tagName.lower() == meta_name.lower() or
                  n.tagName.lower() == u'orx:%s' % meta_name.lower())]
    if len(uuid_tags) == 0:
        return None

    uuid_tag = uuid_tags[0]
    return uuid_tag.firstChild.nodeValue.strip() if uuid_tag.firstChild\
        else None