echo_bot: illustrate close()

examples/echo_bot.rs

@@ -1,4 +1,4 @@
-use futures::{future, Sink, Stream};
+use futures::{future, Future, Sink, Stream};
 use std::env::args;
 use std::process::exit;
 use tokio::runtime::current_thread::Runtime;
@@ -23,36 +23,50 @@ fn main() {
 
     // Make the two interfaces for sending and receiving independent
     // of each other so we can move one into a closure.
-    let (mut sink, stream) = client.split();
+    let (sink, stream) = client.split();
-    // Wrap sink in Option so that we can take() it for the send(self)
+    let mut sink_state = Some(sink);
-    // to consume and return it back when ready.
-    let mut send = move |stanza| {
-        sink.start_send(stanza).expect("start_send");
-    };
     // Main loop, processes events
-    let done = stream.for_each(|event| {
+    let done = stream.for_each(move |event| {
+        let mut sink_future = None;
+
         if event.is_online() {
             println!("Online!");
 
             let presence = make_presence();
-            send(presence);
+            let sink = sink_state.take().unwrap();
+            sink_future = Some(Box::new(sink.send(presence)));
         } else if let Some(message) = event
             .into_stanza()
             .and_then(|stanza| Message::try_from(stanza).ok())
         {
-            // This is a message we'll echo
             match (message.from, message.bodies.get("")) {
-                (Some(from), Some(body)) => {
+                (Some(ref from), Some(ref body)) if body.0 == "die" => {
+                    println!("Secret die command triggered by {}", from);
+                    let sink = sink_state.as_mut().unwrap();
+                    sink.close().expect("close");
+                }
+                (Some(ref from), Some(ref body)) => {
                     if message.type_ != MessageType::Error {
-                        let reply = make_reply(from, &body.0);
+                        // This is a message we'll echo
-                        send(reply);
+                        let reply = make_reply(from.clone(), &body.0);
+                        let sink = sink_state.take().unwrap();
+                        sink_future = Some(Box::new(sink.send(reply)));
                     }
                 }
-                _ => (),
+                _ => {}
             }
-        }
+        };
 
-        Box::new(future::ok(()))
+        sink_future
+            .map(|future| {
+                let wait_send: Box<Future<Item = (), Error = tokio_xmpp::Error>> =
+                    Box::new(future
+                             .map(|sink| {
+                                 sink_state = Some(sink);
+                             }));
+                wait_send
+            })
+            .unwrap_or_else(|| Box::new(future::ok(())))
     });
 
     // Start polling `done`