fix: leak in todomvc example (closes #706)

examples/todomvc/src/lib.rs

@@ -43,7 +43,7 @@ impl Todos {
     }
 
     pub fn remove(&mut self, id: Uuid) {
-        self.0.retain(|todo| todo.id != id);
+        self.retain(|todo| todo.id != id);
     }
 
     pub fn remaining(&self) -> usize {
@@ -76,7 +76,23 @@ impl Todos {
     }
 
     fn clear_completed(&mut self) {
-        self.0.retain(|todo| !todo.completed.get());
+        self.retain(|todo| !todo.completed.get());
+    }
+
+    fn retain(&mut self, mut f: impl FnMut(&Todo) -> bool) {
+        self.0.retain(|todo| {
+            let retain = f(todo);
+            // because these signals are created at the top level,
+            // they are owned by the <TodoMVC/> component and not 
+            // by the individual <Todo/> components. This means 
+            // that if they are not manually disposed when removed, they 
+            // will be held onto until the <TodoMVC/> is unmounted.
+            if !retain {
+                todo.title.dispose();
+                todo.completed.dispose();
+            }
+            retain
+        })
     }
 }
 
@@ -136,7 +152,7 @@ pub fn TodoMVC(cx: Scope) -> impl IntoView {
 
     // Handle the three filter modes: All, Active, and Completed
     let (mode, set_mode) = create_signal(cx, Mode::All);
-    window_event_listener_untyped("hashchange", move |_| {
+    window_event_listener(ev::hashchange, move |_| {
         let new_mode =
             location_hash().map(|hash| route(&hash)).unwrap_or_default();
         set_mode(new_mode);