Sync state (param passing)

examples/hello_world.rs

@@ -2,6 +2,8 @@ use std::sync::Arc;
 
 use osui::{prelude::*, rsx};
 
+pub struct Count(pub State<u16>);
+
 fn main() {
     let console = Console::new();
     console.run(app);
@@ -9,7 +11,7 @@ fn main() {
 
 fn app(cx: &Arc<Context>) -> View {
     let count = use_state(0);
-    let mount = use_mount();
+    let mount = use_mount_manual();
 
     use_effect(
         {
@@ -27,6 +29,18 @@ 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) {
@@ -46,13 +60,15 @@ fn app(cx: &Arc<Context>) -> View {
         for %count (i in 0..count.get_dl()) {
             "{i}" @Point { x: 0, y: i };
         }
+
+        !mount mount
     }
     .view(cx.clone())
 }
 
 fn my_component(cx: &Arc<Context>) -> View {
-    let count = use_state(0);
     let mount = use_mount();
+    let count = use_sync_state(cx, 0, |Count(v)| v.get_dl());
 
     use_effect(
         {

src/macros.rs

@@ -106,6 +106,14 @@ macro_rules! rsx_scope {
         $crate::rsx_scope!($rsx, $($rest)*);
     };
 
+    ($rsx:expr, !mount $mount:ident $($rest:tt)*) => {
+        {
+            $mount.mount();
+        }
+
+        $crate::rsx_scope!($rsx, $($rest)*);
+    };
+
     ($rsx:expr,) => {};
 }
 

src/state.rs

@@ -1,13 +1,16 @@
 use std::{
+    any::Any,
     fmt::{Debug, Display, Formatter, Result as FmtResult},
     ops::{Deref, DerefMut},
     sync::{Arc, Mutex, MutexGuard},
 };
 
+use crate::prelude::Context;
+
 #[derive(Clone)]
 pub struct HookEffect(Arc<Mutex<dyn FnMut() + Send + Sync>>);
 
-#[derive(Debug, Clone)]
+#[derive(Debug)]
 pub struct State<T> {
     value: Arc<Mutex<T>>,
     dependents: Arc<Mutex<Vec<HookEffect>>>,
@@ -19,8 +22,8 @@ pub struct Inner<'a, T> {
     updated: bool,
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone)]
-pub struct Mount;
+pub struct Mount(Arc<Mutex<bool>>, Arc<Mutex<Vec<HookEffect>>>);
 
 pub fn use_state<T>(v: T) -> State<T> {
     State {
@@ -57,6 +60,13 @@ impl<T> State<T> {
             d.call();
         }
     }
+
+    pub fn clone(&self) -> Self {
+        Self {
+            dependents: self.dependents.clone(),
+            value: self.value.clone(),
+        }
+    }
 }
 
 impl<T: Display> Display for State<T> {
@@ -117,7 +127,21 @@ impl<T> HookDependency for State<T> {
 
 impl HookDependency for Mount {
     fn on_update(&self, hook: HookEffect) {
+        if *self.0.lock().unwrap() {
             hook.call();
+        } else {
+            self.1.lock().unwrap().push(hook);
+        }
+    }
+}
+
+impl Mount {
+    pub fn mount(&self) {
+        *self.0.lock().unwrap() = true;
+        for hook_effect in self.1.lock().unwrap().iter() {
+            hook_effect.call();
+        }
+        self.1.lock().unwrap().clear();
     }
 }
 
@@ -137,5 +161,31 @@ pub fn use_effect<F: FnMut() + Send + Sync + 'static>(f: F, dependencies: &[&dyn
 }
 
 pub fn use_mount() -> Mount {
-    Mount
+    Mount(Arc::new(Mutex::new(true)), Arc::new(Mutex::new(Vec::new())))
+}
+
+pub fn use_mount_manual() -> Mount {
+    Mount(
+        Arc::new(Mutex::new(false)),
+        Arc::new(Mutex::new(Vec::new())),
+    )
+}
+
+pub fn use_sync_state<
+    T: Send + Sync + 'static,
+    E: Any + 'static,
+    D: Fn(&E) -> T + Send + Sync + 'static,
+>(
+    cx: &Arc<Context>,
+    v: T,
+    decoder: D,
+) -> State<T> {
+    let state = use_state(v);
+
+    cx.on_event({
+        let state = state.clone();
+        move |_, v: &E| state.set(decoder(v))
+    });
+
+    state
 }