MOBILE-3320 core: Support alerts on top of loading

src/core/classes/ion-loading.ts

@@ -13,43 +13,155 @@
 // limitations under the License.
 
 import { CoreUtils } from '@services/utils/utils';
+import { LoadingController } from '@singletons';
+
+/**
+ * Dismiss listener.
+ */
+export type CoreIonLoadingElementDismissListener = () => unknown;
 
 /**
  * Class to improve the behaviour of HTMLIonLoadingElement.
- * It's not a subclass of HTMLIonLoadingElement because we cannot override the dismiss function.
+ *
+ * In addition to present/dismiss, this loader can also be paused/resumed in order to allow stacking
+ * modals in top of one another without interfering. Conceptually, a paused loader is still
+ * active but will not be shown in the UI.
  */
 export class CoreIonLoadingElement {
 
-    protected isPresented = false;
-    protected isDismissed = false;
+    protected scheduled = false;
+    protected paused = false;
+    protected listeners: CoreIonLoadingElementDismissListener[] = [];
+    protected asyncLoadingElement?: Promise<HTMLIonLoadingElement>;
 
-    constructor(public loading: HTMLIonLoadingElement) { }
+    constructor(protected text?: string) { }
 
-    // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    async dismiss(data?: any, role?: string): Promise<boolean> {
-        if (!this.isPresented || this.isDismissed) {
-            this.isDismissed = true;
+    /**
+     * Dismiss the loading element.
+     *
+     * @param data Dismiss data.
+     * @param role Dismiss role.
+     */
+    async dismiss(data?: unknown, role?: string): Promise<void> {
+        if (this.paused) {
+            this.paused = false;
+            this.listeners.forEach(listener => listener());
 
-            return true;
+            return;
         }
 
-        this.isDismissed = true;
+        if (!this.asyncLoadingElement) {
+            if (this.scheduled) {
+                this.scheduled = false;
+                this.listeners.forEach(listener => listener());
+            }
 
-        return this.loading.dismiss(data, role);
+            return;
+        }
+
+        const asyncLoadingElement = this.asyncLoadingElement;
+        delete this.asyncLoadingElement;
+
+        const loadingElement = await asyncLoadingElement;
+        await loadingElement.dismiss(data, role);
+
+        this.listeners.forEach(listener => listener());
     }
 
     /**
-     * Present the loading.
+     * Register dismiss listener.
+     *
+     * @param listener Listener.
+     */
+    onDismiss(listener: CoreIonLoadingElementDismissListener): void {
+        this.listeners.push(listener);
+    }
+
+    /**
+     * Hide the loading element.
+     */
+    async pause(): Promise<void> {
+        if (!this.asyncLoadingElement) {
+            return;
+        }
+
+        this.paused = true;
+
+        const asyncLoadingElement = this.asyncLoadingElement;
+        delete this.asyncLoadingElement;
+
+        const loadingElement = await asyncLoadingElement;
+        loadingElement.dismiss();
+    }
+
+    /**
+     * Present the loading element.
      */
     async present(): Promise<void> {
+        if (this.paused || this.scheduled || this.asyncLoadingElement) {
+            return;
+        }
+
         // Wait a bit before presenting the modal, to prevent it being displayed if dismiss is called fast.
+        this.scheduled = true;
+
         await CoreUtils.wait(40);
 
-        if (!this.isDismissed) {
-            this.isPresented = true;
+        if (!this.scheduled) {
+            return;
+        }
 
-            await this.loading.present();
+        // Present modal.
+        this.scheduled = false;
+
+        await this.presentLoadingElement();
+    }
+
+    /**
+     * Show loading element.
+     */
+    async resume(): Promise<void> {
+        if (!this.paused) {
+            return;
+        }
+
+        this.paused = false;
+
+        await this.presentLoadingElement();
+    }
+
+    /**
+     * Update text in the loading element.
+     *
+     * @param text Text.
+     */
+    async updateText(text: string): Promise<void> {
+        this.text = text;
+
+        if (!this.asyncLoadingElement) {
+            return;
+        }
+
+        const loadingElement = await this.asyncLoadingElement;
+        const contentElement = loadingElement.querySelector('.loading-content');
+
+        if (contentElement) {
+            contentElement.innerHTML = text;
         }
     }
 
+    /**
+     * Create and present the loading element.
+     */
+    private async presentLoadingElement(): Promise<void> {
+        let resolveLoadingElement!: ((loadingElement: HTMLIonLoadingElement) => void);
+        this.asyncLoadingElement = new Promise(resolve => resolveLoadingElement = resolve);
+
+        const loadingElement = await LoadingController.create({ message: this.text });
+
+        await loadingElement.present();
+
+        resolveLoadingElement(loadingElement);
+    }
+
 }

src/core/features/fileuploader/services/fileuploader-helper.ts

@@ -873,10 +873,7 @@ export class CoreFileUploaderHelperProvider {
             return;
         }
 
-        const contentElement = modal.loading?.querySelector('.loading-content');
-        if (contentElement) {
-            contentElement.innerHTML = Translate.instant(stringKey, { $a: perc.toFixed(1) });
-        }
+        modal.updateText(Translate.instant(stringKey, { $a: perc.toFixed(1) }));
     }
 
 }

src/core/services/utils/dom.ts

@@ -30,15 +30,7 @@ import { CoreIonLoadingElement } from '@classes/ion-loading';
 import { CoreCanceledError } from '@classes/errors/cancelederror';
 import { CoreAnyError, CoreError } from '@classes/errors/error';
 import { CoreSilentError } from '@classes/errors/silenterror';
-import {
-    makeSingleton,
-    Translate,
-    AlertController,
-    LoadingController,
-    ToastController,
-    PopoverController,
-    ModalController,
-} from '@singletons';
+import { makeSingleton, Translate, AlertController, ToastController, PopoverController, ModalController } from '@singletons';
 import { CoreLogger } from '@singletons/logger';
 import { CoreFileSizeSum } from '@services/plugin-file-delegate';
 import { CoreNetworkError } from '@classes/errors/network-error';
@@ -66,6 +58,7 @@ export class CoreDomUtilsProvider {
     protected lastInstanceId = 0;
     protected debugDisplay = false; // Whether to display debug messages. Store it in a variable to make it synchronous.
     protected displayedAlerts: Record<string, HTMLIonAlertElement> = {}; // To prevent duplicated alerts.
+    protected activeLoadingModals: CoreIonLoadingElement[] = [];
     protected logger: CoreLogger;
 
     constructor(protected domSanitizer: DomSanitizer) {
@@ -1216,6 +1209,10 @@ export class CoreDomUtilsProvider {
 
         const alert = await AlertController.create(options);
 
+        if (Object.keys(this.displayedAlerts).length === 0) {
+            await Promise.all(this.activeLoadingModals.slice(0).reverse().map(modal => modal.pause()));
+        }
+
         // eslint-disable-next-line promise/catch-or-return
         alert.present().then(() => {
             if (hasHTMLTags) {
@@ -1231,9 +1228,14 @@ export class CoreDomUtilsProvider {
         this.displayedAlerts[alertId] = alert;
 
         // Set the callbacks to trigger an observable event.
-        // eslint-disable-next-line promise/catch-or-return, promise/always-return
-        alert.onDidDismiss().then(() => {
+        // eslint-disable-next-line promise/catch-or-return
+        alert.onDidDismiss().then(async () => {
             delete this.displayedAlerts[alertId];
+
+            // eslint-disable-next-line promise/always-return
+            if (Object.keys(this.displayedAlerts).length === 0) {
+                await Promise.all(this.activeLoadingModals.map(modal => modal.resume()));
+            }
         });
 
         if (autocloseTime && autocloseTime > 0) {
@@ -1447,11 +1449,17 @@ export class CoreDomUtilsProvider {
             text = Translate.instant(text);
         }
 
-        const loadingElement = await LoadingController.create({
-            message: text,
+        const loading = new CoreIonLoadingElement(text);
+
+        loading.onDismiss(() => {
+            const index = this.activeLoadingModals.indexOf(loading);
+
+            if (index !== -1) {
+                this.activeLoadingModals.splice(index, 1);
+            }
         });
 
-        const loading = new CoreIonLoadingElement(loadingElement);
+        this.activeLoadingModals.push(loading);
 
         await loading.present();
 
@@ -1480,19 +1488,19 @@ export class CoreDomUtilsProvider {
             });
         }
 
-        const alert = await AlertController.create({
+        const alert = await this.showAlertWithOptions({
             message: message,
             buttons: buttons,
         });
 
-        await alert.present();
-
         const isDevice = CoreApp.isAndroid() || CoreApp.isIOS();
         if (!isDevice) {
             // Treat all anchors so they don't override the app.
             const alertMessageEl: HTMLElement | null = alert.querySelector('.alert-message');
             alertMessageEl && this.treatAnchors(alertMessageEl);
         }
+
+        await alert.onDidDismiss();
     }
 
     /**