fix(macos/ios): Add handler for web content process termination (fix #14371) (#14523)

Author: JeffTsang

.changes/web-content-process-termination.md

@@ -0,0 +1,7 @@
+---
+"tauri": "minor:feat"
+"tauri-runtime": "minor:feat"
+"tauri-runtime-wry": "minor:feat"
+---
+
+Add handler for web content process termination on macOS and iOS.

crates/tauri-runtime-wry/src/lib.rs

@@ -5054,6 +5054,35 @@ You may have it installed on another user account, but it is not available for t
 
     webview_builder =
       webview_builder.with_allow_link_preview(webview_attributes.allow_link_preview);
+
+    if let Some(on_web_content_process_terminate_handler) =
+      pending.on_web_content_process_terminate_handler
+    {
+      webview_builder = webview_builder
+        .with_on_web_content_process_terminate_handler(on_web_content_process_terminate_handler);
+    } else {
+      log::debug!("web content process terminated");
+      let context_ = context.clone();
+      let window_id_ = window_id.clone();
+      webview_builder = webview_builder.with_on_web_content_process_terminate_handler(move || {
+        if let Ok(windows) = &context_.main_thread.windows.0.try_borrow() {
+          if let Some(window) = windows.get(&*window_id_.lock().unwrap()) {
+            if let Some(webview) = window.webviews.iter().find(|w| w.id == id) {
+              match webview.reload() {
+                Ok(_) => log::debug!("webview reloaded"),
+                Err(e) => log::error!("failed to reload webview: {}", e),
+              }
+            } else {
+              log::error!("failed to find webview")
+            }
+          } else {
+            log::error!("failed to get window")
+          }
+        } else {
+          log::error!("failed to borrow windows")
+        }
+      });
+    }
   }
 
   #[cfg(target_os = "ios")]

crates/tauri-runtime/src/webview.rs

@@ -41,6 +41,9 @@ type DocumentTitleChangedHandler = dyn Fn(String) + Send + 'static;
 
 type DownloadHandler = dyn Fn(DownloadEvent) -> bool + Send + Sync;
 
+#[cfg(any(target_os = "macos", target_os = "ios"))]
+type OnWebContentProcessTerminateHandler = dyn Fn() + Send;
+
 #[cfg(target_os = "ios")]
 type InputAccessoryViewBuilderFn = dyn Fn(&objc2_ui_kit::UIView) -> Option<objc2::rc::Retained<objc2_ui_kit::UIView>>
   + Send
@@ -225,6 +228,9 @@ pub struct PendingWebview<T: UserEvent, R: Runtime<T>> {
   pub on_page_load_handler: Option<Box<OnPageLoadHandler>>,
 
   pub download_handler: Option<Arc<DownloadHandler>>,
+
+  #[cfg(any(target_os = "macos", target_os = "ios"))]
+  pub on_web_content_process_terminate_handler: Option<Box<OnWebContentProcessTerminateHandler>>,
 }
 
 impl<T: UserEvent, R: Runtime<T>> PendingWebview<T, R> {
@@ -251,6 +257,8 @@ impl<T: UserEvent, R: Runtime<T>> PendingWebview<T, R> {
         web_resource_request_handler: None,
         on_page_load_handler: None,
         download_handler: None,
+        #[cfg(any(target_os = "macos", target_os = "ios"))]
+        on_web_content_process_terminate_handler: None,
       })
     }
   }

crates/tauri/src/app.rs

@@ -67,6 +67,9 @@ pub type SetupHook<R> =
   Box<dyn FnOnce(&mut App<R>) -> std::result::Result<(), Box<dyn std::error::Error>> + Send>;
 /// A closure that is run every time a page starts or finishes loading.
 pub type OnPageLoad<R> = dyn Fn(&Webview<R>, &PageLoadPayload<'_>) + Send + Sync + 'static;
+/// A closure that is run when the web content process terminates.
+#[cfg(any(target_os = "macos", target_os = "ios"))]
+pub type OnWebContentProcessTerminate<R> = dyn Fn(&Webview<R>) + Send + Sync + 'static;
 pub type ChannelInterceptor<R> =
   Box<dyn Fn(&Webview<R>, CallbackFn, usize, &InvokeResponseBody) -> bool + Send + Sync + 'static>;
 
@@ -1483,6 +1486,10 @@ pub struct Builder<R: Runtime> {
   /// Page load hook.
   on_page_load: Option<Arc<OnPageLoad<R>>>,
 
+  /// Web content process termination hook.
+  #[cfg(any(target_os = "macos", target_os = "ios"))]
+  on_web_content_process_terminate: Option<Arc<OnWebContentProcessTerminate<R>>>,
+
   /// All passed plugins
   plugins: PluginStore<R>,
 
@@ -1569,6 +1576,8 @@ impl<R: Runtime> Builder<R> {
       .into_string(),
       channel_interceptor: None,
       on_page_load: None,
+      #[cfg(any(target_os = "macos", target_os = "ios"))]
+      on_web_content_process_terminate: None,
       plugins: PluginStore::default(),
       uri_scheme_protocols: Default::default(),
       state: StateManager::new(),
@@ -1749,6 +1758,23 @@ tauri::Builder::default()
     self
   }
 
+  /// Defines the web content process termination hook.
+  ///
+  /// ## Platform-specific
+  ///
+  /// - **Linux / Windows / Android:** Unsupported.
+  #[cfg(any(target_os = "macos", target_os = "ios"))]
+  #[must_use]
+  pub fn on_web_content_process_terminate<F>(mut self, on_web_content_process_terminate: F) -> Self
+  where
+    F: Fn(&Webview<R>) + Send + Sync + 'static,
+  {
+    self
+      .on_web_content_process_terminate
+      .replace(Arc::new(on_web_content_process_terminate));
+    self
+  }
+
   /// Adds a Tauri application plugin.
   ///
   /// A plugin is created using the [`crate::plugin::Builder`] struct.Check its documentation for more information.
@@ -2197,6 +2223,8 @@ tauri::Builder::default()
       self.plugins,
       self.invoke_handler,
       self.on_page_load,
+      #[cfg(any(target_os = "macos", target_os = "ios"))]
+      self.on_web_content_process_terminate,
       self.uri_scheme_protocols,
       self.state,
       #[cfg(desktop)]

crates/tauri/src/ipc/protocol.rs

@@ -571,6 +571,8 @@ mod tests {
       PluginStore::default(),
       Box::new(|_| false),
       None,
+      #[cfg(any(target_os = "macos", target_os = "ios"))]
+      None,
       Default::default(),
       StateManager::new(),
       Default::default(),
@@ -687,6 +689,8 @@ mod tests {
       PluginStore::default(),
       Box::new(|_| false),
       None,
+      #[cfg(any(target_os = "macos", target_os = "ios"))]
+      None,
       Default::default(),
       StateManager::new(),
       Default::default(),

crates/tauri/src/manager/mod.rs

@@ -31,6 +31,9 @@ use crate::{
   Assets, Context, DebugAppIcon, EventName, Pattern, Runtime, StateManager, Webview, Window,
 };
 
+#[cfg(any(target_os = "macos", target_os = "ios"))]
+use crate::app::OnWebContentProcessTerminate;
+
 #[cfg(desktop)]
 mod menu;
 #[cfg(all(desktop, feature = "tray-icon"))]
@@ -251,6 +254,9 @@ impl<R: Runtime> AppManager<R> {
     plugins: PluginStore<R>,
     invoke_handler: Box<InvokeHandler<R>>,
     on_page_load: Option<Arc<OnPageLoad<R>>>,
+    #[cfg(any(target_os = "macos", target_os = "ios"))] on_web_content_process_terminate: Option<
+      Arc<OnWebContentProcessTerminate<R>>,
+    >,
     uri_scheme_protocols: HashMap<String, Arc<webview::UriSchemeProtocol<R>>>,
     state: StateManager,
     #[cfg(desktop)] menu_event_listener: Vec<crate::app::GlobalMenuEventListener<AppHandle<R>>>,
@@ -284,6 +290,8 @@ impl<R: Runtime> AppManager<R> {
         webviews: Mutex::default(),
         invoke_handler,
         on_page_load,
+        #[cfg(any(target_os = "macos", target_os = "ios"))]
+        on_web_content_process_terminate,
         uri_scheme_protocols: Mutex::new(uri_scheme_protocols),
         event_listeners: Arc::new(webview_event_listeners),
         invoke_initialization_script,
@@ -756,6 +764,8 @@ mod test {
       PluginStore::default(),
       Box::new(|_| false),
       None,
+      #[cfg(any(target_os = "macos", target_os = "ios"))]
+      None,
       Default::default(),
       StateManager::new(),
       Default::default(),

crates/tauri/src/manager/webview.rs

@@ -28,6 +28,9 @@ use crate::{
   EventLoopMessage, EventTarget, Manager, Runtime, Scopes, UriSchemeContext, Webview, Window,
 };
 
+#[cfg(any(target_os = "macos", target_os = "ios"))]
+use crate::app::OnWebContentProcessTerminate;
+
 use super::{
   window::{DragDropPayload, DRAG_DROP_EVENT, DRAG_ENTER_EVENT, DRAG_LEAVE_EVENT, DRAG_OVER_EVENT},
   {AppManager, EmitPayload},
@@ -70,6 +73,9 @@ pub struct WebviewManager<R: Runtime> {
   pub invoke_handler: Box<InvokeHandler<R>>,
   /// The page load hook, invoked when the webview performs a navigation.
   pub on_page_load: Option<Arc<OnPageLoad<R>>>,
+  /// The web content process termination hook.
+  #[cfg(any(target_os = "macos", target_os = "ios"))]
+  pub on_web_content_process_terminate: Option<Arc<OnWebContentProcessTerminate<R>>>,
   /// The webview protocols available to all webviews.
   pub uri_scheme_protocols: Mutex<HashMap<String, Arc<UriSchemeProtocol<R>>>>,
   /// Webview event listeners to all webviews.
@@ -304,6 +310,29 @@ impl<R: Runtime> WebviewManager<R> {
         }
       }));
 
+    #[cfg(any(target_os = "macos", target_os = "ios"))]
+    if pending.on_web_content_process_terminate_handler.is_none() {
+      let app_manager_ = manager.manager_owned();
+      if app_manager_
+        .webview
+        .on_web_content_process_terminate
+        .is_some()
+      {
+        let label_ = pending.label.clone();
+        pending
+          .on_web_content_process_terminate_handler
+          .replace(Box::new(move || {
+            if let Some(w) = app_manager_.get_webview(&label_) {
+              if let Some(on_web_content_process_terminate) =
+                &app_manager_.webview.on_web_content_process_terminate
+              {
+                on_web_content_process_terminate(&w);
+              }
+            }
+          }));
+      }
+    }
+
     #[cfg(feature = "protocol-asset")]
     if !registered_scheme_protocols.contains(&"asset".into()) {
       let asset_scope = app_manager