def validate_nrml(request):
    """
    Leverage oq-risklib to check if a given XML text is a valid NRML

    :param request:
        a `django.http.HttpRequest` object containing the mandatory
        parameter 'xml_text': the text of the XML to be validated as NRML

    :returns: a JSON object, containing:
        * 'valid': a boolean indicating if the provided text is a valid NRML
        * 'error_msg': the error message, if any error was found
                       (None otherwise)
        * 'error_line': line of the given XML where the error was found
                        (None if no error was found or if it was not a
                        validation error)
    """
    xml_text = request.POST.get('xml_text')
    if not xml_text:
        return HttpResponseBadRequest(
            'Please provide the "xml_text" parameter')
    xml_file = gettemp(xml_text, suffix='.xml')
    try:
        nrml.to_python(xml_file)
    except ExpatError as exc:
        return _make_response(error_msg=str(exc),
                              error_line=exc.lineno,
                              valid=False)
    except Exception as exc:
        # get the exception message
        exc_msg = exc.args[0]
        if isinstance(exc_msg, bytes):
            exc_msg = exc_msg.decode('utf-8')   # make it a unicode object
        elif isinstance(exc_msg, str):
            pass
        else:
            # if it is another kind of object, it is not obvious a priori how
            # to extract the error line from it
            return _make_response(
                error_msg=str(exc_msg), error_line=None, valid=False)
        # if the line is not mentioned, the whole message is taken
        error_msg = exc_msg.split(', line')[0]
        # check if the exc_msg contains a line number indication
        search_match = re.search(r'line \d+', exc_msg)
        if search_match:
            error_line = int(search_match.group(0).split()[1])
        else:
            error_line = None
        return _make_response(
            error_msg=error_msg, error_line=error_line, valid=False)
    else:
        return _make_response(error_msg=None, error_line=None, valid=True)
Leverage oq-risklib to check if a given XML text is a valid NRML

    :param request:
        a `django.http.HttpRequest` object containing the mandatory
        parameter 'xml_text': the text of the XML to be validated as NRML

    :returns: a JSON object, containing:
        * 'valid': a boolean indicating if the provided text is a valid NRML
        * 'error_msg': the error message, if any error was found
                       (None otherwise)
        * 'error_line': line of the given XML where the error was found
                        (None if no error was found or if it was not a
                        validation error)