/** If the url is a valid reference, convert it to a URL, else return it unchanged. */
protected String convertReferenceUrl(String url) {
// make a reference
Reference ref = EntityManager.newReference(url);
// if it didn't recognize this, return it unchanged
if (ref.isKnownType()) {
// return the reference's url
String refUrl = ref.getUrl();
if (refUrl != null) {
return refUrl;
}
}
return url;
}
