@@ -204,6 +204,40 @@ impl Message {
pub fn get_best_subject(&self, preferred_langs: Vec<&str>) -> Option<(Lang, &Subject)> {
Message::get_best::<Subject>(&self.subjects, preferred_langs)
}
+
+ /// Try to extract the given payload type from the message's payloads.
+ ///
+ /// Returns the first matching payload element as parsed struct or its
+ /// parse error. If no element matches, `Ok(None)` is returned. If an
+ /// element matches, but fails to parse, it is nontheless removed from
+ /// the message.
+ ///
+ /// Elements which do not match the given type are not removed.
+ pub fn extract_payload<T: TryFrom<Element, Error = Error>>(
+ &mut self,
+ ) -> Result<Option<T>, Error> {
+ let mut buf = Vec::with_capacity(self.payloads.len());
+ let mut iter = self.payloads.drain(..);
+ let mut result = Ok(None);
+ for item in &mut iter {
+ match T::try_from(item) {
+ Ok(v) => {
+ result = Ok(Some(v));
+ break;
+ }
+ Err(Error::TypeMismatch(_, _, residual)) => {
+ buf.push(residual);
+ }
+ Err(other) => {
+ result = Err(other);
+ break;
+ }
+ }
+ }
+ buf.extend(iter);
+ std::mem::swap(&mut buf, &mut self.payloads);
+ result
+ }
}
impl TryFrom<Element> for Message {
@@ -460,4 +494,27 @@ mod tests {
let elem2 = message.into();
assert_eq!(elem1, elem2);
}
+
+ #[test]
+ fn test_extract_payload() {
+ use super::super::attention::Attention;
+ use super::super::pubsub::event::PubSubEvent;
+
+ #[cfg(not(feature = "component"))]
+ let elem: Element = "<message xmlns='jabber:client' to='coucou@example.org' type='chat'><attention xmlns='urn:xmpp:attention:0'/></message>".parse().unwrap();
+ #[cfg(feature = "component")]
+ let elem: Element = "<message xmlns='jabber:component:accept' to='coucou@example.org' type='chat'><attention xmlns='urn:xmpp:attention:0'/></message>".parse().unwrap();
+ let mut message = Message::try_from(elem).unwrap();
+ assert_eq!(message.payloads.len(), 1);
+ match message.extract_payload::<PubSubEvent>() {
+ Ok(None) => (),
+ other => panic!("unexpected result: {:?}", other),
+ };
+ assert_eq!(message.payloads.len(), 1);
+ match message.extract_payload::<Attention>() {
+ Ok(Some(_)) => (),
+ other => panic!("unexpected result: {:?}", other),
+ };
+ assert_eq!(message.payloads.len(), 0);
+ }
}