Fix router example.

packages/yew-router/src/router.rs

@@ -1,4 +1,5 @@
 //! Router Component.
+use std::rc::Rc;
 
 use crate::prelude::*;
 use yew::prelude::*;
@@ -30,78 +31,65 @@ impl PartialEq for RouterState {
     }
 }
 
-#[doc(hidden)]
-pub enum Msg {
-    ReRender,
+pub(crate) enum RouterStateAction {
+    Navigate,
+    ReplaceHistory(AnyHistory),
 }
 
-/// The Router component.
-///
-/// This provides [`History`] context to its children and switches.
-///
-/// You only need one `<Router />` for each application.
-pub struct Router {
-    _listener: HistoryListener,
-    history: AnyHistory,
-    ctr: u32,
-}
+impl Reducible for RouterState {
+    type Action = RouterStateAction;
 
-impl Component for Router {
-    type Message = Msg;
-    type Properties = RouterProps;
-
-    fn create(ctx: &Context<Self>) -> Self {
-        let link = ctx.link().clone();
-
-        let listener = ctx
-            .props()
-            .history
-            .listen(move || link.send_message(Msg::ReRender));
+    fn reduce(self: Rc<Self>, action: Self::Action) -> Rc<Self> {
+        let history = match action {
+            RouterStateAction::Navigate => self.history(),
+            RouterStateAction::ReplaceHistory(m) => m,
+        };
 
         Self {
-            _listener: listener,
-            history: ctx.props().history.clone(),
-            ctr: 0,
+            history,
+            ctr: self.ctr + 1,
         }
+        .into()
     }
+}
 
-    fn update(&mut self, _ctx: &Context<Self>, msg: Self::Message) -> bool {
-        match msg {
-            Msg::ReRender => {
-                self.ctr += 1;
-                true
-            }
-        }
-    }
-
-    fn changed(&mut self, ctx: &Context<Self>) -> bool {
-        let link = ctx.link().clone();
-
-        if self.history != ctx.props().history {
-            self._listener = ctx
-                .props()
-                .history
-                .listen(move || link.send_message(Msg::ReRender));
-
-            self.history = ctx.props().history.clone();
-
-            true
-        } else {
-            false
-        }
+/// The Router component.
+///
+/// This provides [`History`] context to its children and switches.
+///
+/// You only need one `<Router />` for each application.
+#[function_component(Router)]
+pub fn router(props: &RouterProps) -> Html {
+    let RouterProps { history, children } = props.clone();
+
+    let state = use_reducer(|| RouterState {
+        history: history.clone(),
+        ctr: 0,
+    });
+
+    {
+        let state_dispatcher = state.dispatcher();
+
+        use_effect_with_deps(
+            move |history| {
+                state_dispatcher.dispatch(RouterStateAction::ReplaceHistory(history.clone()));
+
+                let listener =
+                    history.listen(move || state_dispatcher.dispatch(RouterStateAction::Navigate));
+
+                // We hold the listener in the destructor.
+                move || {
+                    std::mem::drop(listener);
+                }
+            },
+            history,
+        );
     }
 
-    fn view(&self, ctx: &Context<Self>) -> Html {
-        let state = RouterState {
-            history: self.history.clone().into_any_history(),
-            ctr: self.ctr,
-        };
-
-        html! {
-            <ContextProvider<RouterState> context={state}>
-                {ctx.props().children.clone()}
-            </ContextProvider<RouterState>>
-        }
+    html! {
+        <ContextProvider<RouterState> context={(*state).clone()}>
+            {children}
+        </ContextProvider<RouterState>>
     }
 }