added websockets example to the guide

examples/websockets/Cargo.toml

@@ -8,10 +8,10 @@ edition = "2018"
 crate-type = ["cdylib"]
 
 [dependencies]
-wasm-bindgen = "0.2.44"
+wasm-bindgen = "0.2.45"
 
 [dependencies.web-sys]
-version = "0.3.21"
+version = "0.3.22"
 features = [
   "ErrorEvent",
   "MessageEvent",

examples/websockets/README.md

@@ -21,5 +21,3 @@ http
 # or use python
 python -m SimpleHTTPServer
 ```
-
-Make sure that you have `WebSockets` server running

examples/websockets/index.html

@@ -7,4 +7,4 @@
 </head>
 <bodt>
 </bodt>
-</html>
+</html>

examples/websockets/src/lib.rs

@@ -14,16 +14,17 @@ extern "C" {
 
 #[wasm_bindgen(start)]
 pub fn start_websocket() -> Result<(), JsValue> {
-    // Assuming, you run a WebSockets server at localhost:8081
-    // You'll also need to disable CORS in case of serving this example from
-    // the different `host:port` then your WebSockets server
-    let ws = WebSocket::new("ws://localhost:8081")
-        .expect("should create a socket");
+    // Connect to an echo server
+    let ws = WebSocket::new("wss://echo.websocket.org")?;
 
     // create callback
     let onmessage_callback = Closure::wrap(Box::new(move |e: MessageEvent| {
         // handle message
-        console_log!("message event, received data {:?}", e.data());
+        let response = e
+            .data()
+            .as_string()
+            .expect("Can't convert received data to a string");
+        console_log!("message event, received data: {:?}", response);
     }) as Box<dyn FnMut(MessageEvent)>);
     // set message event handler on WebSocket
     ws.set_onmessage(Some(onmessage_callback.as_ref().unchecked_ref()));
@@ -31,7 +32,7 @@ pub fn start_websocket() -> Result<(), JsValue> {
     onmessage_callback.forget();
 
     let onerror_callback = Closure::wrap(Box::new(move |e: ErrorEvent| {
-        console_log!("error event {:?}", e);
+        console_log!("error event: {:?}", e);
     }) as Box<dyn FnMut(ErrorEvent)>);
     ws.set_onerror(Some(onerror_callback.as_ref().unchecked_ref()));
     onerror_callback.forget();
@@ -40,8 +41,8 @@ pub fn start_websocket() -> Result<(), JsValue> {
     let onopen_callback = Closure::wrap(Box::new(move |_| {
         console_log!("socket opened");
         match cloned_ws.send_with_str("ping") {
-            Ok(_) => console_log!("message sent successfully"),
-            Err(err) => console_log!("error sending message {:?}", err),
+            Ok(_) => console_log!("message successfully sent"),
+            Err(err) => console_log!("error sending message: {:?}", err),
         }
     }) as Box<dyn FnMut(JsValue)>);
     ws.set_onopen(Some(onopen_callback.as_ref().unchecked_ref()));