prompt user when there are unsaved changes, #1692

src/public/app/services/app_context.js

@@ -12,6 +12,7 @@ import keyboardActionsService from "./keyboard_actions.js";
 import MobileScreenSwitcherExecutor from "../widgets/mobile_widgets/mobile_screen_switcher.js";
 import MainTreeExecutors from "./main_tree_executors.js";
 import protectedSessionHolder from "./protected_session_holder.js";
+import toast from "./toast.js";
 
 class AppContext extends Component {
     constructor(isMainWindow) {
@@ -19,6 +20,7 @@ class AppContext extends Component {
 
         this.isMainWindow = isMainWindow;
         this.executors = [];
+        this.beforeUnloadListeners = [];
     }
 
     setLayout(layout) {
@@ -104,6 +106,15 @@ class AppContext extends Component {
     getComponentByEl(el) {
         return $(el).closest(".component").prop('component');
     }
+
+    addBeforeUnloadListener(obj) {
+        if (typeof WeakRef !== "function") {
+            // older browsers don't support WeakRef
+            return;
+        }
+
+        this.beforeUnloadListeners.push(new WeakRef(obj));
+    }
 }
 
 const appContext = new AppContext(window.glob.isMainWindow);
@@ -112,7 +123,29 @@ const appContext = new AppContext(window.glob.isMainWindow);
 $(window).on('beforeunload', () => {
     protectedSessionHolder.resetSessionCookie();
 
-    appContext.triggerEvent('beforeUnload');
+    let allSaved = true;
+
+    appContext.beforeUnloadListeners = appContext.beforeUnloadListeners.filter(wr => !!wr.deref());
+
+    for (const weakRef of appContext.beforeUnloadListeners) {
+        const component = weakRef.deref();
+
+        if (!component) {
+            continue;
+        }
+
+        if (!component.beforeUnloadEvent()) {
+            console.log(`Component ${component.componentId} is not finished saving its state.`);
+
+            toast.showMessage("Please wait for a couple of seconds for the save to finish, then you can try again.", 10000);
+
+            allSaved = false;
+        }
+    }
+
+    if (!allSaved) {
+        return "some string";
+    }
 });
 
 function isNotePathInAddress() {

src/public/app/services/spaced_update.js

@@ -15,11 +15,27 @@ export default class SpacedUpdate {
 
     async updateNowIfNecessary() {
         if (this.changed) {
-            this.changed = false;
+            this.changed = false; // optimistic...k
-            await this.updater();
+
+            try {
+                await this.updater();
+            }
+            catch (e) {
+                this.changed = true;
+
+                throw e;
+            }
         }
     }
 
+    isAllSavedAndTriggerUpdate() {
+        const allSaved = !this.changed;
+
+        this.updateNowIfNecessary();
+
+        return allSaved;
+    }
+
     triggerUpdate() {
         if (!this.changed) {
             return;

src/public/app/services/tab_manager.js

@@ -27,6 +27,8 @@ export default class TabManager extends Component {
                 openTabs: JSON.stringify(openTabs)
             });
         });
+
+        appContext.addBeforeUnloadListener(this);
     }
 
     /** @type {TabContext[]} */
@@ -329,6 +331,8 @@ export default class TabManager extends Component {
 
     beforeUnloadEvent() {
         this.tabsUpdate.updateNowIfNecessary();
+
+        return true; // don't block closing the tab, this metadata is not that important
     }
 
     openNewTabCommand() {

src/public/app/widgets/note_detail.js

@@ -54,8 +54,6 @@ export default class NoteDetailWidget extends TabAwareWidget {
 
         this.typeWidgets = {};
 
-        const updateInterval = utils.isDesktop() ? 1000 : 5000;
-
         this.spacedUpdate = new SpacedUpdate(async () => {
             const {note} = this.tabContext;
             const {noteId} = note;
@@ -66,7 +64,9 @@ export default class NoteDetailWidget extends TabAwareWidget {
             protectedSessionHolder.touchProtectedSessionIfNecessary(note);
 
             await server.put('notes/' + noteId, dto, this.componentId);
-        }, updateInterval);
+        });
+
+        appContext.addBeforeUnloadListener(this);
     }
 
     isEnabled() {
@@ -295,7 +295,7 @@ export default class NoteDetailWidget extends TabAwareWidget {
     }
 
     beforeUnloadEvent() {
-        this.spacedUpdate.updateNowIfNecessary();
+        return this.spacedUpdate.isAllSavedAndTriggerUpdate();
     }
 
     textPreviewDisabledEvent({tabContext}) {

src/public/app/widgets/note_title.js

@@ -3,6 +3,7 @@ import utils from "../services/utils.js";
 import protectedSessionHolder from "../services/protected_session_holder.js";
 import server from "../services/server.js";
 import SpacedUpdate from "../services/spaced_update.js";
+import appContext from "../services/app_context.js";
 
 const TPL = `
 <div class="note-title-container">
@@ -37,6 +38,8 @@ export default class NoteTitleWidget extends TabAwareWidget {
 
             await server.put(`notes/${this.noteId}/change-title`, {title});
         });
+
+        appContext.addBeforeUnloadListener(this);
     }
 
     doRender() {
@@ -101,6 +104,6 @@ export default class NoteTitleWidget extends TabAwareWidget {
     }
 
     beforeUnloadEvent() {
-        this.spacedUpdate.updateNowIfNecessary();
+        return this.spacedUpdate.isAllSavedAndTriggerUpdate();
     }
 }