Problem while parsing alerts from alerts.weather.gov

[Rogelio Alejandro Ortiz Sevilla]

Good day everyone:

Please forgive me if this is not the right place to ask. I just didn't
find a place to post my questions but here.

I'm currently using your library to handle Cap Alerts (works very
well). I have only one problem. When I create a new CapXmlParser
object with validation turned on, and then, try to parse any alert
from the NOAA site (http://alerts.weather.gov/cap/us.php?x=0).I get
the following exception:

cvc-pattern-valid: Value '' is not facet-valid with respect to pattern
'\s*[^\s,&<]+,[^\s,&<]+,\d\d\d\d-\d\d-\d\dT\d\d:\d\d:\d\d[-,+]\d\d:\d
\d(\s+[^\s,&<]+,[^\s,&<]+,\d\d\d\d-\d\d-\d\dT\d\d:\d\d:\d\d[-,+]\d\d:\d
\d)*\s*' for type '#AnonType_referencesalert'.; cvc-type.3.1.3: The
value '' of element 'references' is not valid.

If I understand correctly, the xsd is requiring a value on the
references tag. If no references are intended, the <references> tag
must not be included. However, the NOAA site is throwing alerts with
empty value <references> tag.

My question is: how can I enable the google cap library to handle the
NOAA alerts without having to turn off the validation??

Thanks a lot in advance.

[Steve Hakusa]

Hi Rogelio,

You're right.  The CAP alerts currently being produced by NOAA at http://alerts.weather.gov/cap/us.php?x=0 are not valid CAP.  They are fixing this in their CAP 1.2 implementation (wiki).

I have an uncommitted change that adds a version of parseFrom that will return parse errors instead of throwing them in a CapException.

+ /**

+ * Parse the given alert.

+ *

+ * @param is the input source to read the CAP XML to parse

+ * @param parseErrors a list to which to add any non-fatal errors during parsing

+ * @return the parsed alert

+ * @throws NotCapException if the XML is not CAP XML

+ * @throws SAXParseException on XML parsing error

+ */

+ public Alert parseFrom(InputSource is, List<Reason> parseErrors)

+ throws NotCapException, SAXParseException {

Then you can work around the problem by catching and ignoring the error, something like:

    for (CapException.Reason reason : new XercesCapExceptionMapper().map(reasons)) {

      if (reason.getType() == CapException.Type.INVALID_REFERENCES) {

        if (capAlert.getReferences().getValueCount() == 0) {

          continue;

        }

      }

      unhandled.add(reason);

    }

    if (!unhandled.isEmpty()) {

      throw new CapException(unhandled);

    }

I'll try to get that change committed in the next day or so.  I'm glad you are finding the library to be useful.

Steve