State syncing

examples/hello_world.rs

@@ -13,6 +13,9 @@ fn app(cx: &Arc<Context>) -> View {
     let count = use_state(0);
     let mount = use_mount_manual();
 
+    // Sync state with children
+    use_sync_effect(cx, &count, |v| Count(v.clone()), &[&mount, &count]);
+
     use_effect(
         {
             let count = count.clone();
@@ -29,18 +32,6 @@ fn app(cx: &Arc<Context>) -> View {
         &[&mount],
     );
 
-    // Pass the count to the children
-    use_effect(
-        {
-            let count = count.clone();
-            let cx = cx.clone();
-            move || {
-                cx.emit_event(&Count(count.clone()));
-            }
-        },
-        &[&mount],
-    );
-
     rsx! {
         // Static scope
         my_component (ctx, view) {
@@ -67,25 +58,9 @@ fn app(cx: &Arc<Context>) -> View {
 }
 
 fn my_component(cx: &Arc<Context>) -> View {
-    let mount = use_mount();
+    // Sync state with parent
     let count = use_sync_state(cx, 0, |Count(v)| v.get_dl());
 
-    use_effect(
-        {
-            let count = count.clone();
-            move || loop {
-                std::thread::sleep(std::time::Duration::from_millis(500));
-                let mut count = count.get();
-                if *count > 5 {
-                    *count = 0;
-                    continue;
-                }
-                *count += 1;
-            }
-        },
-        &[&mount],
-    );
-
     rsx! {
         "Count: {count}"
     }

src/state.rs

@@ -189,3 +189,25 @@ pub fn use_sync_state<
 
     state
 }
+
+pub fn use_sync_effect<
+    T: Send + Sync + 'static,
+    Ev: 'static,
+    E: Fn(&State<T>) -> Ev + Send + Sync + 'static,
+>(
+    cx: &Arc<Context>,
+    state: &State<T>,
+    encoder: E,
+    deps: &[&dyn HookDependency],
+) {
+    use_effect(
+        {
+            let state = state.clone();
+            let cx = cx.clone();
+            move || {
+                cx.emit_event(&encoder(&state));
+            }
+        },
+        deps,
+    );
+}