add on_connect_fail() to ClientExt

CHANGELOG.md

@@ -36,6 +36,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Add `ClientConnectorWasm` and `wasm_client` feature. Added `chat-client-wasm` example to show a WASM client that compiles. It currently only listens to the chat and can't input anything since browser does not have a terminal.
 - Refactor `Socket` and `Client` to not depend on `tokio` when compiling to WASM. This is a breaking change as the `Client` API now exposes `async_channel` error types instead of `tokio` error types, and `Client::call_with()` now takes an `async_channel::Sender` instead of a `tokio` oneshot.
 - Add unimplemented socket close codes.
+- Add `ClientExt::on_connect_fail()` for custom handling of connection attempt failures. By default the client will continue trying to connect.
 
 
 Migration guide:

src/client.rs

@@ -235,20 +235,41 @@ pub trait ClientExt: Send {
     /// Type the custom call - parameters passed to `on_call`.
     type Call: Send;
 
-    /// Handler for text messages from the server. Returning an error will force-close the client.
+    /// Handler for text messages from the server.
+    ///
+    /// Returning an error will force-close the client.
     async fn on_text(&mut self, text: String) -> Result<(), Error>;
-    /// Handler for binary messages from the server. Returning an error will force-close the client.
+    /// Handler for binary messages from the server.
+    ///
+    /// Returning an error will force-close the client.
     async fn on_binary(&mut self, bytes: Vec<u8>) -> Result<(), Error>;
-    /// Handler for custom calls from other parts from your program. Returning an error will force-close the client.
+    /// Handler for custom calls from other parts from your program.
+    ///
+    /// Returning an error will force-close the client.
+    ///
     /// This is useful for concurrency and polymorphism.
     async fn on_call(&mut self, call: Self::Call) -> Result<(), Error>;
 
-    /// Called when the client successfully connected(or reconnected). Returned errors will be ignored.
+    /// Called when the client successfully connected (or reconnected).
+    ///
+    /// Returning an error will force-close the client.
     async fn on_connect(&mut self) -> Result<(), Error> {
         Ok(())
     }
 
-    /// Called when the connection is closed by the server. Returning an error will force-close the client.
+    /// Called when the client fails a connection/reconnection attempt.
+    ///
+    /// Returning an error will force-close the client.
+    ///
+    /// By default, the client will continue trying to connect.
+    /// Return [`ClientCloseMode::Close`] here to fully close instead.
+    async fn on_connect_fail(&mut self, _error: WSError) -> Result<ClientCloseMode, Error> {
+        Ok(ClientCloseMode::Reconnect)
+    }
+
+    /// Called when the connection is closed by the server.
+    ///
+    /// Returning an error will force-close the client.
     ///
     /// By default, the client will try to reconnect. Return [`ClientCloseMode::Close`] here to fully close instead.
     ///
@@ -259,6 +280,8 @@ pub trait ClientExt: Send {
 
     /// Called when the connection is closed by the socket dying.
     ///
+    /// Returning an error will force-close the client.
+    ///
     /// By default, the client will try to reconnect. Return [`ClientCloseMode::Close`] here to fully close instead.
     ///
     /// For reconnections, use `ClientConfig::reconnect_interval`.
@@ -276,24 +299,20 @@ pub trait ClientExt: Send {
 pub trait ClientConnector {
     type Handle: enfync::Handle;
     type Message: Into<RawMessage> + From<RawMessage> + std::fmt::Debug + Send + 'static;
-    type WSError: std::error::Error + Into<WSError>;
+    type WSError: std::error::Error + Into<WSError> + Send;
     type Socket: SinkExt<Self::Message, Error = Self::WSError>
         + StreamExt<Item = Result<Self::Message, Self::WSError>>
         + Unpin
         + Send
         + 'static;
-    type ConnectError: std::error::Error + Send;
 
     /// Get the connector's runtime handle.
     fn handle(&self) -> Self::Handle;
 
     /// Connect to a websocket server.
     ///
     /// Returns `Err` if the request is invalid.
-    async fn connect(
-        &self,
-        client_config: &ClientConfig,
-    ) -> Result<Self::Socket, Self::ConnectError>;
+    async fn connect(&self, client_config: &ClientConfig) -> Result<Self::Socket, Self::WSError>;
 }
 
 /// An `ezsockets` client.
@@ -581,10 +600,7 @@ async fn client_connect<E: ClientExt, Connector: ClientConnector>(
         match result {
             Ok(socket_impl) => {
                 tracing::info!("successfully connected");
-                if let Err(err) = client.on_connect().await {
-                    tracing::error!("calling on_connect() failed due to {}, closing client", err);
-                    return Err(err);
-                }
+                client.on_connect().await?;
                 let socket = Socket::new(
                     socket_impl,
                     config.socket_config.clone().unwrap_or_default(),
@@ -598,6 +614,13 @@ async fn client_connect<E: ClientExt, Connector: ClientConnector>(
                     err,
                     config.reconnect_interval.as_secs()
                 );
+                match client.on_connect_fail(err.into()).await? {
+                    ClientCloseMode::Reconnect => (),
+                    ClientCloseMode::Close => {
+                        tracing::trace!("client closed itself after a connection failure");
+                        return Ok(None);
+                    }
+                }
             }
         };
 

src/client_connectors/client_connector_tokio.rs

@@ -40,7 +40,6 @@ impl ClientConnector for ClientConnectorTokio {
     type Socket = tokio_tungstenite::WebSocketStream<
         tokio_tungstenite::MaybeTlsStream<tokio::net::TcpStream>,
     >;
-    type ConnectError = tungstenite::error::Error;
 
     /// Get the connector's runtime handle.
     fn handle(&self) -> Self::Handle {
@@ -50,7 +49,7 @@ impl ClientConnector for ClientConnectorTokio {
     /// Connect to a websocket server.
     ///
     /// Returns `Err` if the request is invalid.
-    async fn connect(&self, config: &ClientConfig) -> Result<Self::Socket, Self::ConnectError> {
+    async fn connect(&self, config: &ClientConfig) -> Result<Self::Socket, Self::WSError> {
         let request = config.connect_http_request();
         let (socket, _) = tokio_tungstenite::connect_async(request).await?;
         Ok(socket)

src/client_connectors/client_connector_wasm.rs

@@ -84,7 +84,6 @@ impl ClientConnector for ClientConnectorWasm {
     type Message = tokio_tungstenite_wasm::Message;
     type WSError = tokio_tungstenite_wasm::Error;
     type Socket = WebSocketStreamProxy;
-    type ConnectError = tokio_tungstenite_wasm::Error;
 
     /// Get the connector's runtime handle.
     fn handle(&self) -> Self::Handle {
@@ -97,7 +96,7 @@ impl ClientConnector for ClientConnectorWasm {
     ///
     /// Panics if any headers were added to the client config. Websockets on browser does not support
     /// additional headers (use [`ClientConfig::query_parameter()`] instead).
-    async fn connect(&self, config: &ClientConfig) -> Result<Self::Socket, Self::ConnectError> {
+    async fn connect(&self, config: &ClientConfig) -> Result<Self::Socket, Self::WSError> {
         if config.headers().len() > 0 {
             panic!("client may not submit HTTP headers in WASM connection requests");
         }

src/lib.rs

@@ -52,5 +52,7 @@ cfg_if::cfg_if! {
     }
 }
 
+pub use tokio_tungstenite_wasm::Error as WSError;
+
 pub type Error = Box<dyn std::error::Error + Send + Sync>;
 pub type Request = http::Request<()>;