Refactor auth API client. Implement proper error handling.

web-ui/crate/src/api/auth.rs

@@ -5,20 +5,45 @@ use wasm_bindgen::JsCast;
 use wasm_bindgen_futures::JsFuture;
 use web_sys::{console, Request, RequestCredentials, RequestInit, RequestMode, Response};
 
+/// A struct representing an error coming back from the REST API
+/// endpoint. The API server encodes any errors as JSON objects with a
+/// "message" property containing the error, and a bad status code.
+#[derive(Debug, Serialize, Deserialize)]
+struct ApiError {
+    message: Option<String>,
+}
+
 #[derive(Debug, Serialize, Deserialize)]
 struct LoginResponse {
     jwt_token: String,
 }
 
-async fn make_request(request: Request) -> Result<JsValue, UiError> {
+async fn make_request<T>(request: Request) -> Result<T, UiError>
+where
+    T: for<'a> Deserialize<'a>,
+{
     let window = web_sys::window().unwrap();
 
     let resp_value = JsFuture::from(window.fetch_with_request(&request)).await?;
     let resp: Response = resp_value.dyn_into().unwrap();
+    let ok = resp.ok();
 
     let json = JsFuture::from(resp.json()?).await?;
     console::log_1(&json);
-    Ok(json)
+    //if ok, attempt to deserialize into T.
+    //if not ok, attempt to deserialize into struct with message, and fall back
+    //if that fails.
+    if ok {
+        let data: T = json.into_serde()?;
+        Ok(data)
+    } else {
+        let data: ApiError = json.into_serde()?;
+        Err(UiError::ApiError(data.message.unwrap_or_else(|| {
+            let status_text = resp.status_text();
+            let status = resp.status();
+            format!("[{}] - {} - unknown api error", status, status_text)
+        })))
+    }
 }
 
 pub async fn login(username: &str, password: &str) -> Result<String, UiError> {
@@ -42,10 +67,7 @@ pub async fn login(username: &str, password: &str) -> Result<String, UiError> {
     request.headers().set("Content-Type", "application/json")?;
     request.headers().set("Accept", "application/json")?;
 
-    //TODO don't unwrap the response. OR... change it so we have a standard response.
-    let response = make_request(request).await?;
-    let response: LoginResponse = response.into_serde().unwrap();
-
+    let response: LoginResponse = make_request(request).await?;
     Ok(response.jwt_token)
 }
 
@@ -62,8 +84,6 @@ pub async fn refresh_jwt() -> Result<String, UiError> {
     request.headers().set("Accept", "application/json")?;
 
     //TODO don't unwrap the response. OR... change it so we have a standard response.
-    let response = make_request(request).await?;
-    let response: LoginResponse = response.into_serde().unwrap();
-
+    let response: LoginResponse = make_request(request).await?;
     Ok(response.jwt_token)
 }

web-ui/crate/src/components/error_message.rs

@@ -0,0 +1,62 @@
+use crate::api;
+use crate::error::UiError;
+use crate::state::{Action, WebUiDispatcher};
+use std::rc::Rc;
+use wasm_bindgen::{prelude::Closure, JsCast};
+use wasm_bindgen_futures::spawn_local;
+use web_sys::FocusEvent;
+use yew::prelude::*;
+use yewdux::dispatch::Dispatcher;
+use yewdux::prelude::*;
+use yewtil::NeqAssign;
+
+#[doc(hidden)]
+pub(crate) struct YewduxErrorMessage {
+    dispatch: WebUiDispatcher,
+    link: ComponentLink<YewduxErrorMessage>,
+}
+
+pub(crate) type ErrorMessage = WithDispatch<YewduxErrorMessage>;
+
+impl YewduxErrorMessage {
+    fn view_error(&self, error: &str) -> Html {
+        html! {
+            <div class="alert alert-danger" role="alert">
+                { error }
+            </div>
+        }
+    }
+}
+
+impl Component for YewduxErrorMessage {
+    type Message = ();
+    type Properties = WebUiDispatcher;
+
+    fn create(dispatch: Self::Properties, link: ComponentLink<Self>) -> Self {
+        Self { dispatch, link }
+    }
+
+    fn update(&mut self, action: Self::Message) -> ShouldRender {
+        false
+    }
+
+    fn change(&mut self, dispatch: Self::Properties) -> ShouldRender {
+        self.dispatch.neq_assign(dispatch)
+    }
+
+    fn rendered(&mut self, _first_render: bool) {}
+
+    fn view(&self) -> Html {
+        html! {
+            <div>
+            {
+                for self.dispatch.state().error_messages.iter().map(|error| {
+                    self.view_error(error)
+                })
+            }
+            </div>
+        }
+    }
+
+    fn destroy(&mut self) {}
+}

web-ui/crate/src/components/mod.rs

@@ -1 +1,2 @@
+pub mod error_message;
 pub mod login;

web-ui/crate/src/lib.rs

@@ -1,3 +1,4 @@
+use crate::components::error_message::ErrorMessage;
 use crate::components::login::Login;
 use rooms::RoomList;
 use rooms::YewduxRoomList;
@@ -42,6 +43,7 @@ fn render_route(routes: &AppRoute) -> Html {
             html! {
                 <div>
                     <Login />
+                    <ErrorMessage />
                     <RoomList />
                 </div>
             }
@@ -49,47 +51,6 @@ fn render_route(routes: &AppRoute) -> Html {
     }
 }
 
-// struct AppMenu;
-
-// impl Component for AppMenu {
-//     type Message = ();
-//     type Properties = ();
-
-//     fn create(_: Self::Properties, _link: ComponentLink<Self>) -> Self {
-//         Self
-//     }
-
-//     fn update(&mut self, _msg: Self::Message) -> ShouldRender {
-//         false
-//     }
-
-//     fn change(&mut self, _: Self::Properties) -> ShouldRender {
-//         false
-//     }
-
-//     fn view(&self) -> Html {
-//         html! {
-//              <ul>
-//                 <li>
-//                     <AppAnchor route=AppRoute::Index>{"Home"}</AppAnchor>
-//                 </li>
-//                 <li>
-//                     <AppAnchor route=AppRoute::Oaths>{"Oaths"}</AppAnchor>
-//                 </li>
-//                 <li>
-//                     <AppAnchor route=AppRoute::Commitments>{"Commitments"}</AppAnchor>
-//                 </li>
-//                 <li>
-//                     <AppAnchor route=AppRoute::Studies>{"Studies"}</AppAnchor>
-//                 </li>
-//                 <li>
-//                     <AppAnchor route=AppRoute::RunicDivination>{"Runic Divination"}</AppAnchor>
-//                 </li>
-//              </ul>
-//         }
-//     }
-// }
-
 struct App;
 
 impl Component for App {

web-ui/crate/src/rooms.rs

@@ -1,6 +1,6 @@
 use crate::api;
 use crate::error::UiError;
-use crate::state::{Action, Room, WebUiDispatcher};
+use crate::state::{Action, DispatchExt, Room, WebUiDispatcher};
 use std::sync::Arc;
 use wasm_bindgen_futures::spawn_local;
 use web_sys::console;
@@ -44,10 +44,13 @@ async fn load_rooms(dispatch: &WebUiDispatcher) -> Result<(), UiError> {
     Ok(())
 }
 
-async fn do_refresh_jwt(dispatch: &WebUiDispatcher) -> Result<(), UiError> {
-    let jwt = api::auth::refresh_jwt().await?;
-    dispatch.send(Action::UpdateJwt(jwt));
-    Ok(())
+async fn do_refresh_jwt(dispatch: &WebUiDispatcher) {
+    let refresh = api::auth::refresh_jwt().await;
+
+    match refresh {
+        Ok(jwt) => dispatch.send(Action::UpdateJwt(jwt)),
+        Err(e) => dispatch.dispatch_error(e),
+    }
 }
 
 impl Component for YewduxRoomList {
@@ -101,9 +104,7 @@ impl Component for YewduxRoomList {
 
         let refresh_jwt = self.link.callback(move |_| {
             let dispatch = dispatch3.clone();
-            spawn_local(async move {
-                do_refresh_jwt(&*dispatch).await;
-            });
+            spawn_local(async move { do_refresh_jwt(&*dispatch).await });
         });
 
         html! {

web-ui/crate/src/state.rs

@@ -1,3 +1,5 @@
+use crate::error::UiError;
+use wasm_bindgen::{prelude::Closure, JsCast};
 use yewdux::prelude::*;
 
 #[derive(Clone)]
@@ -10,27 +12,33 @@ pub(crate) struct Room {
 pub(crate) struct WebUiState {
     pub jwt_token: Option<String>,
     pub rooms: Vec<Room>,
+    pub error_messages: Vec<String>,
 }
 
 pub(crate) enum Action {
     UpdateJwt(String),
     AddRoom(Room),
+    ErrorMessage(UiError),
+    ClearErrorMessage,
 }
 
 impl Reducer for WebUiState {
     type Action = Action;
 
     fn new() -> Self {
-        Self {
-            jwt_token: None,
-            rooms: vec![],
-        }
+        Self::default()
     }
 
     fn reduce(&mut self, action: Self::Action) -> bool {
         match action {
             Action::UpdateJwt(jwt_token) => self.jwt_token = Some(jwt_token),
             Action::AddRoom(room) => self.rooms.push(room.clone()),
+            Action::ErrorMessage(error) => self.error_messages.push(error.to_string()),
+            Action::ClearErrorMessage => {
+                if self.error_messages.len() > 0 {
+                    self.error_messages.remove(0);
+                }
+            }
         };
 
         true
@@ -38,3 +46,33 @@ impl Reducer for WebUiState {
 }
 
 pub(crate) type WebUiDispatcher = DispatchProps<ReducerStore<WebUiState>>;
+
+pub(crate) trait DispatchExt {
+    /// Dispatch an error message and then clear it from the state
+    /// after a few seconds.
+    fn dispatch_error(&self, error: UiError);
+}
+
+impl DispatchExt for WebUiDispatcher {
+    fn dispatch_error(&self, error: UiError) {
+        self.send(Action::ErrorMessage(error));
+
+        // This is a very hacky way to do this. At the very least, we
+        // should not leak memory, and preferably there's a cleaner
+        // way to actually dispatch the clear action.
+        let window = web_sys::window().unwrap();
+        let dispatch = self.clone();
+        let clear_it = Closure::wrap(
+            Box::new(move || dispatch.send(Action::ClearErrorMessage)) as Box<dyn Fn()>
+        );
+
+        window
+            .set_timeout_with_callback_and_timeout_and_arguments_0(
+                clear_it.as_ref().unchecked_ref(),
+                4000,
+            )
+            .expect("could not add clear error handler.");
+
+        clear_it.forget();
+    }
+}