fix(webview): release controller references safely

crates/ability/src/helper/webview.rs

@@ -1,5 +1,6 @@
 use std::{
     borrow::Cow,
+    cell::RefCell,
     collections::HashMap,
     rc::Rc,
     sync::{Arc, Mutex},
@@ -59,22 +60,37 @@ pub struct WebViewInitData<'a> {
 #[derive(Clone)]
 pub struct Webview {
     tag: String,
-    inner: Rc<ObjectRef>,
+    /// N-API reference to the ArkTS WebView controller. `None` once the
+    /// reference has been released (dispose or last clone drop).
+    inner: Rc<RefCell<Option<ObjectRef>>>,
     web_view_native: Rc<Web>,
 }
 
 impl Webview {
     pub fn new(tag: String, inner: ObjectRef) -> Result<Self> {
         let native_instance = Web::new(tag.clone());
         Ok(Self {
-            inner: Rc::new(inner),
+            inner: Rc::new(RefCell::new(Some(inner))),
             web_view_native: Rc::new(native_instance),
             tag,
         })
     }
 
-    pub fn inner(&self) -> Rc<ObjectRef> {
-        self.inner.clone()
+    /// Borrow the live N-API object reference.
+    fn object_ref(&self) -> Result<std::cell::Ref<'_, ObjectRef>> {
+        std::cell::Ref::filter_map(self.inner.borrow(), |inner| inner.as_ref())
+            .map_err(|_| Error::from_reason("webview reference already released"))
+    }
+
+    /// Release the N-API reference. Only the last clone may actually unref;
+    /// earlier clones simply mark the shared slot empty so a later drop is a
+    /// no-op.
+    fn release_native_ref(&self) {
+        if let Some(object_ref) = self.inner.borrow_mut().take() {
+            if let Some(env) = get_main_thread_env().borrow().as_ref() {
+                let _ = object_ref.unref(env);
+            }
+        }
     }
 
     pub fn tag(&self) -> String {
@@ -85,7 +101,7 @@ impl Webview {
     pub fn url(&self) -> Result<String> {
         if let Some(env) = get_main_thread_env().borrow().as_ref() {
             let url_js_function = self
-                .inner
+                .object_ref()?
                 .get_value(env)?
                 .get_named_property::<Function<'_, (), String>>("getUrl")?;
             url_js_function.call(())
@@ -97,7 +113,7 @@ impl Webview {
     /// Load a url in the webview
     pub fn load_url(&self, url: &str) -> Result<()> {
         if let Some(env) = get_main_thread_env().borrow().as_ref() {
-            let load_url_js_function = self.inner.get_value(env)?.get_named_property::<Function<
+            let load_url_js_function = self.object_ref()?.get_value(env)?.get_named_property::<Function<
                 '_,
                 FnArgs<(String, Option<HashMap<String, String>>)>,
                 (),
@@ -114,7 +130,7 @@ impl Webview {
     pub fn load_url_with_headers(&self, url: &str, headers: http::HeaderMap) -> Result<()> {
         if let Some(env) = get_main_thread_env().borrow().as_ref() {
             let load_url_with_headers_js_function = self
-                .inner
+                .object_ref()?
                 .get_value(env)?
                 .get_named_property::<Function<'_, FnArgs<(String, HashMap<String, String>)>, ()>>(
                     "loadUrl",
@@ -135,7 +151,7 @@ impl Webview {
     pub fn load_html(&self, html: &str) -> Result<()> {
         if let Some(env) = get_main_thread_env().borrow().as_ref() {
             let load_html_js_function = self
-                .inner
+                .object_ref()?
                 .get_value(env)?
                 .get_named_property::<Function<'_, String, ()>>("loadHtml")?;
             load_html_js_function.call(html.to_string())?;
@@ -149,7 +165,7 @@ impl Webview {
     pub fn set_zoom(&self, zoom: f64) -> Result<()> {
         if let Some(env) = get_main_thread_env().borrow().as_ref() {
             let set_zoom_js_function = self
-                .inner
+                .object_ref()?
                 .get_value(env)?
                 .get_named_property::<Function<'_, f64, ()>>("zoom")?;
             set_zoom_js_function.call(zoom)?;
@@ -163,7 +179,7 @@ impl Webview {
     pub fn reload(&self) -> Result<()> {
         if let Some(env) = get_main_thread_env().borrow().as_ref() {
             let reload_js_function = self
-                .inner
+                .object_ref()?
                 .get_value(env)?
                 .get_named_property::<Function<'_, (), ()>>("refresh")?;
             reload_js_function.call(())?;
@@ -177,7 +193,7 @@ impl Webview {
     pub fn focus(&self) -> Result<()> {
         if let Some(env) = get_main_thread_env().borrow().as_ref() {
             let focus_js_function = self
-                .inner
+                .object_ref()?
                 .get_value(env)?
                 .get_named_property::<Function<'_, (), ()>>("requestFocus")?;
             focus_js_function.call(())?;
@@ -198,7 +214,7 @@ impl Webview {
     ) -> Result<()> {
         if let Some(env) = get_main_thread_env().borrow().as_ref() {
             let evaluate_js_js_function = self
-                .inner
+                .object_ref()?
                 .get_value(env)?
                 .get_named_property::<Function<'_, FnArgs<(String, Function<'_, String, ()>)>, ()>>(
                     "runJavaScript",
@@ -226,7 +242,7 @@ impl Webview {
     pub fn cookies_with_url(&self, url: &str) -> Result<String> {
         if let Some(env) = get_main_thread_env().borrow().as_ref() {
             let cookies_js_function = self
-                .inner
+                .object_ref()?
                 .get_value(env)?
                 .get_named_property::<Function<'_, String, String>>("getCookies")?;
             cookies_js_function.call(url.to_string())
@@ -238,7 +254,7 @@ impl Webview {
     pub fn set_background_color(&self, color: &str) -> Result<()> {
         if let Some(env) = get_main_thread_env().borrow().as_ref() {
             let set_background_color_js_function = self
-                .inner
+                .object_ref()?
                 .get_value(env)?
                 .get_named_property::<Function<'_, String, ()>>("setBackgroundColor")?;
             set_background_color_js_function.call(color.to_string())?;
@@ -251,7 +267,7 @@ impl Webview {
     pub fn set_visible(&self, visible: bool) -> Result<()> {
         if let Some(env) = get_main_thread_env().borrow().as_ref() {
             let set_visible_js_function = self
-                .inner
+                .object_ref()?
                 .get_value(env)?
                 .get_named_property::<Function<'_, bool, ()>>("setVisible")?;
             set_visible_js_function.call(visible)?;
@@ -262,12 +278,20 @@ impl Webview {
     }
 
     pub fn dispose(&self) -> Result<()> {
-        if let Some(env) = get_main_thread_env().borrow().as_ref() {
+        let disposed = if let Some(env) = get_main_thread_env().borrow().as_ref() {
             let dispose_js_function = self
-                .inner
+                .object_ref()?
                 .get_value(env)?
                 .get_named_property::<Function<'_, (), ()>>("dispose")?;
-            dispose_js_function.call(())?;
+            dispose_js_function.call(()).is_ok()
+        } else {
+            false
+        };
+        // Release the N-API reference regardless of ArkTS dispose outcome:
+        // an unreachable or half-disposed controller must not stay pinned
+        // forever. Subsequent calls are no-ops.
+        self.release_native_ref();
+        if disposed {
             Ok(())
         } else {
             Err(Error::from_reason("Failed to get main thread env"))
@@ -277,7 +301,7 @@ impl Webview {
     pub fn clear_all_browsing_data(&self) -> Result<()> {
         if let Some(env) = get_main_thread_env().borrow().as_ref() {
             let clear_all_browsing_data_js_function = self
-                .inner
+                .object_ref()?
                 .get_value(env)?
                 .get_named_property::<Function<'_, (), ()>>("clearAllBrowsingData")?;
             clear_all_browsing_data_js_function.call(())?;
@@ -481,3 +505,16 @@ impl CustomProtocolResponder {
         (self.responder)(Response::from_parts(parts, body.into()))
     }
 }
+
+impl Drop for Webview {
+    fn drop(&mut self) {
+        // Last-resort N-API reference release for clones that were never
+        // explicitly disposed. Only the last clone may release the shared
+        // slot: ephemeral clones are created for every native call (snapshot
+        // pattern) and dropped immediately, so releasing from any clone would
+        // invalidate the controller after the first call.
+        if Rc::strong_count(&self.inner) == 1 {
+            self.release_native_ref();
+        }
+    }
+}

rust_example/demo_native/src/lib.rs

@@ -9,13 +9,10 @@ use std::{
 };
 
 use napi_derive_ohos::napi;
-use napi_ohos::{
-    bindgen_prelude::{Function, JsObjectValue, Object},
-    Env, Error, Result,
-};
+use napi_ohos::{Env, Error, Result};
 use ohos_hilog_binding::hilog_info;
 use openharmony_ability::{
-    native_web::WebProxyBuilder, Event, InputEvent, OpenHarmonyApp, WebViewBuilder,
+    native_web::WebProxyBuilder, Event, InputEvent, OpenHarmonyApp, WebViewBuilder, Webview,
 };
 use openharmony_ability_derive::ability;
 
@@ -26,7 +23,7 @@ static BACK_PRESS_INTERCEPT_ENABLED: AtomicBool = AtomicBool::new(true);
 
 thread_local! {
     #[allow(clippy::missing_const_for_thread_local)]
-    static WEBVIEW_ID: RefCell<Option<Object<'static>>> = RefCell::new(None);
+    static WEBVIEW: RefCell<Option<Webview>> = RefCell::new(None);
 }
 
 const WEB_TAG: &str = "demo_webview";
@@ -70,7 +67,7 @@ pub fn toggle_back_press_intercept() -> bool {
 }
 
 #[napi]
-pub fn handle_change(env: &Env) -> napi_ohos::Result<()> {
+pub fn handle_change(_env: &Env) -> napi_ohos::Result<()> {
     let web_tag = String::from(WEB_TAG);
 
     let webview = WebViewBuilder::new()
@@ -105,40 +102,29 @@ pub fn handle_change(env: &Env) -> napi_ohos::Result<()> {
         hilog_info!("ohos-rs macro on_page_end");
     });
 
-    let ret: Object<'static> = unsafe {
-        std::mem::transmute::<Object<'_>, Object<'static>>(webview.inner().get_value(env)?)
-    };
-    WEBVIEW_ID.with(|w| {
-        w.replace(Some(ret));
+    WEBVIEW.with(|slot| {
+        slot.replace(Some(webview));
     });
 
     Ok(())
 }
 
 #[napi]
 pub fn set_background_color(_env: &Env, color: String) -> napi_ohos::Result<()> {
-    WEBVIEW_ID.with(|w| {
-        if let Some(webview) = w.borrow().as_ref() {
-            let set_background_color_js_function = webview
-                .get_named_property::<Function<'_, String, ()>>("setBackgroundColor")
-                .unwrap();
-            set_background_color_js_function.call(color).unwrap();
-        }
-    });
-    Ok(())
+    WEBVIEW.with(|slot| {
+        slot.borrow()
+            .as_ref()
+            .map_or(Ok(()), |webview| webview.set_background_color(&color))
+    })
 }
 
 #[napi]
 pub fn set_visible(_env: &Env, visible: bool) -> napi_ohos::Result<()> {
-    WEBVIEW_ID.with(|w| {
-        if let Some(webview) = w.borrow().as_ref() {
-            let set_visible_js_function = webview
-                .get_named_property::<Function<'_, bool, ()>>("setVisible")
-                .unwrap();
-            set_visible_js_function.call(visible).unwrap();
-        }
-    });
-    Ok(())
+    WEBVIEW.with(|slot| {
+        slot.borrow()
+            .as_ref()
+            .map_or(Ok(()), |webview| webview.set_visible(visible))
+    })
 }
 
 #[ability(webview, protocol = "wry,custom,other")]