feat(training): loading progress indicator

apps/showcase/src/components/training/code-editor-control/code-editor-control.component.html

@@ -2,7 +2,13 @@
     <li ngbNavItem class="nav-item" role="presentation" [destroyOnHide]="false">
       <a ngbNavLink class="nav-link" [class.active]="activeTab === 'preview'" (click)="activeTab = 'preview'">Preview</a>
       <ng-template ngbNavContent>
-        <iframe class="w-100 h-100" #iframe allow="cross-origin-isolated" [srcdoc]="'Loading...'"></iframe>
+        @let isLoading = percentProgress() < 100;
+        @if (isLoading) {
+          <div class="w-100 h-100 d-flex align-items-center justify-content-center p-2">
+            <df-progressbar [value]="percentProgress()" [text]="progressLabel()"></df-progressbar>
+          </div>
+        }
+        <iframe class="w-100 h-100" #iframe allow="cross-origin-isolated" [srcdoc]="'Loading...'" [class.invisible]="isLoading"></iframe>
       </ng-template>
     </li>
     <li ngbNavItem class="nav-item" role="presentation" [destroyOnHide]="false">

apps/showcase/src/components/training/code-editor-control/code-editor-control.component.scss

@@ -9,6 +9,10 @@ code-editor-control {
     height: 100%;
   }
 
+  df-progressbar {
+    min-width: 15em;
+  }
+
   .terminal-active-indicator {
     display: inline-block;
     font-weight: bold;

apps/showcase/src/components/training/code-editor-control/code-editor-control.component.ts

@@ -2,6 +2,7 @@ import {
   AfterViewInit,
   ChangeDetectionStrategy,
   Component,
+  computed,
   ElementRef,
   inject,
   Input,
@@ -10,6 +11,7 @@ import {
   ViewEncapsulation
 } from '@angular/core';
 import {toSignal} from '@angular/core/rxjs-interop';
+import {DfProgressbarModule} from '@design-factory/design-factory';
 import {NgbNavModule} from '@ng-bootstrap/ng-bootstrap';
 import {distinctUntilChanged, map, of, repeat, Subject, throttleTime, timeout} from 'rxjs';
 import {WebContainerService} from '../../../services';
@@ -20,7 +22,8 @@ import {CodeEditorTerminalComponent} from '../code-editor-terminal';
   standalone: true,
   imports: [
     CodeEditorTerminalComponent,
-    NgbNavModule
+    NgbNavModule,
+    DfProgressbarModule
   ],
   changeDetection: ChangeDetectionStrategy.OnPush,
   encapsulation: ViewEncapsulation.None,
@@ -54,6 +57,19 @@ export class CodeEditorControlComponent implements OnDestroy, AfterViewInit {
    */
   public readonly terminalActivity = new Subject<void>();
 
+  /**
+   * Loading progression (between 0 and 100)
+   */
+  public readonly percentProgress = computed(() => {
+    const { currentStep, totalSteps } = this.webContainerService.runner.progress();
+    return Math.round(100 * currentStep / totalSteps);
+  });
+
+  /**
+   * Label to use on the load indicator
+   */
+  public readonly progressLabel = computed(() => this.webContainerService.runner.progress().label);
+
   /**
    * Signal with value `true` if the terminal is active, `false` if idle
    * The terminal is considered idle if no activity is received for 2 seconds.

apps/showcase/src/components/training/code-editor-view/code-editor-view.component.html

@@ -1,32 +1,30 @@
-@if (cwdTree$ | async; as tree) {
-    <as-split direction="vertical">
-      <as-split-area [size]="50">
-        <form [formGroup]="form" class="editor overflow-hidden h-100">
-            <as-split direction="horizontal">
-              <as-split-area [size]="25">
-                <monaco-tree (clickFile)="onClickFile($event)"
-                             [tree]="tree"
-                             [currentFile]="project?.startingFile"
-                             [width]="'auto'"
-                             [height]="'auto'"
-                             class="w-100"></monaco-tree>
-              </as-split-area>
-              <as-split-area [size]="75">
-                <ngx-monaco-editor class="h-100 position-relative"
-                                   [options]="editorOptions$ | async"
-                                   formControlName="code">
-                </ngx-monaco-editor>
-              </as-split-area>
-            </as-split>
-        </form>
-      </as-split-area>
-      @if (editorMode === 'interactive') {
-        <as-split-area [size]="50">
-          <code-editor-control class="d-flex flex-column h-100" [showOutput]="project?.commands.length > 0 && tree.length > 0"></code-editor-control>
+<as-split direction="vertical">
+  <as-split-area [size]="50">
+    <form [formGroup]="form" class="editor overflow-hidden h-100">
+      <as-split direction="horizontal">
+        <as-split-area [size]="25">
+          <monaco-tree (clickFile)="onClickFile($event)"
+                       [tree]="(cwdTree$ | async) || []"
+                       [currentFile]="project?.startingFile"
+                       [width]="'auto'"
+                       [height]="'auto'"
+                       class="w-100 editor-view"></monaco-tree>
         </as-split-area>
-      }
-    </as-split>
-}
-@else {
-  <div class="spinner-border" role="status"></div>
-}
+        <as-split-area [size]="75" class="editor-view">
+          @let editorOptions = editorOptions$ | async;
+          @if (editorOptions) {
+            <ngx-monaco-editor class="h-100 position-relative"
+                               [options]="editorOptions"
+                               formControlName="code">
+            </ngx-monaco-editor>
+          }
+        </as-split-area>
+      </as-split>
+    </form>
+  </as-split-area>
+  @if (editorMode === 'interactive') {
+    <as-split-area [size]="50">
+      <code-editor-control class="d-flex flex-column h-100"></code-editor-control>
+    </as-split-area>
+  }
+</as-split>

apps/showcase/src/components/training/code-editor-view/code-editor-view.component.scss

@@ -1,6 +1,4 @@
 monaco-tree {
-  background: #1d1d1d;
-
   .monaco-tree {
     display: flex;
     flex-direction: column;
@@ -24,3 +22,7 @@ ngx-monaco-editor {
     max-height: 100% !important;
   }
 }
+
+.editor-view {
+  background: #1d1d1d;
+}

apps/showcase/src/services/webcontainer/webcontainer-runner.ts

@@ -1,16 +1,22 @@
-import { DestroyRef, inject, Injectable } from '@angular/core';
+import { DestroyRef, inject, Injectable, signal } from '@angular/core';
 import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
 import { type FileSystemTree, type IFSWatcher, WebContainer, type WebContainerProcess } from '@webcontainer/api';
 import { Terminal } from '@xterm/xterm';
 import {
   BehaviorSubject,
+  combineLatest,
   combineLatestWith,
   distinctUntilChanged,
   filter,
   from,
+  fromEvent,
   map,
   Observable,
-  switchMap
+  of,
+  skip,
+  switchMap,
+  take,
+  timeout
 } from 'rxjs';
 import { withLatestFrom } from 'rxjs/operators';
 import { createTerminalStream, killTerminal, makeProcessWritable } from './webcontainer.helpers';
@@ -43,9 +49,17 @@ export class WebContainerRunner {
   };
   private watcher: IFSWatcher | null = null;
 
+  private readonly progressWritable = signal({currentStep: 0, totalSteps: 3, label: 'Initializing web-container'});
+
+  /**
+   * Progress indicator of the loading of a project.
+   */
+  public readonly progress = this.progressWritable.asReadonly();
+
   constructor() {
     const destroyRef = inject(DestroyRef);
     this.instancePromise = WebContainer.boot().then((instance) => {
+      this.progressWritable.update(({totalSteps}) => ({currentStep: 1, totalSteps, label: 'Loading project'}));
       // eslint-disable-next-line no-console
       const unsubscribe = instance.on('error', console.error);
       destroyRef.onDestroy(() => unsubscribe());
@@ -60,20 +74,33 @@ export class WebContainerRunner {
       void this.runCommand(commandElements[0], commandElements.slice(1), cwd);
     });
 
-    this.iframe.pipe(
-      filter((iframe): iframe is HTMLIFrameElement => !!iframe),
-      distinctUntilChanged(),
-      withLatestFrom(this.instancePromise),
-      switchMap(([iframe, instance]) => new Observable((subscriber) => {
+    combineLatest([
+      this.iframe.pipe(
+        filter((iframe): iframe is HTMLIFrameElement => !!iframe),
+        distinctUntilChanged()
+      ),
+      this.instancePromise
+    ]).pipe(
+      switchMap(([iframe, instance]) => new Observable<[typeof iframe, typeof instance, boolean]>((subscriber) => {
+        let shouldSkipFirstLoadEvent = true;
         const serverReadyUnsubscribe = instance.on('server-ready', (_port: number, url: string) => {
+          this.progressWritable.update(({totalSteps}) => ({currentStep: totalSteps - 1, totalSteps, label: 'Bootstrapping application...'}));
           iframe.removeAttribute('srcdoc');
           iframe.src = url;
-          subscriber.next(url);
+          subscriber.next([iframe, instance, shouldSkipFirstLoadEvent]);
+          shouldSkipFirstLoadEvent = false;
         });
         return () => serverReadyUnsubscribe();
       })),
+      switchMap(([iframe, _instance, shouldSkipFirstLoadEvent]) => fromEvent(iframe, 'load').pipe(
+        skip(shouldSkipFirstLoadEvent ? 1 : 0),
+        timeout({each: 20000, with: () => of([])}),
+        take(1)
+      )),
       takeUntilDestroyed()
-    ).subscribe();
+    ).subscribe(() => {
+      this.progressWritable.update(({totalSteps}) => ({currentStep: totalSteps, totalSteps, label: 'Ready!'}));
+    });
 
     this.commandOutput.process.pipe(
       filter((process): process is WebContainerProcess => !!process && !process.output.locked),
@@ -147,10 +174,35 @@ export class WebContainerRunner {
     const process = await instance.spawn(command, args, {cwd: cwd});
     this.commandOutput.process.next(process);
     const exitCode = await process.exit;
-    if (exitCode !== 0) {
+    if (exitCode === 0) {
+      // The process has ended successfully
+      this.progressWritable.update(({currentStep, totalSteps}) => ({
+        currentStep: currentStep + 1,
+        totalSteps,
+        label: this.getCommandLabel(this.commands.value.queue[1])
+      }));
+      this.commands.next({queue: this.commands.value.queue.slice(1), cwd});
+    } else if (exitCode === 143) {
+      // The process was killed by switching to a new project
+      return;
+    } else {
+      // The process has ended with an error
       throw new Error(`Command ${[command, ...args].join(' ')} failed with ${exitCode}!`);
     }
-    this.commands.next({queue: this.commands.value.queue.slice(1), cwd});
+  }
+
+  private getCommandLabel(command: string) {
+    if (!command) {
+      return 'Waiting for server to start...';
+    } else {
+      if (/(npm|yarn) install/.test(command)) {
+        return 'Installing dependencies...';
+      } else if (/^(npm|yarn) (run .*:(build|serve)|(run )?build)/.test(command)) {
+        return 'Building application...';
+      } else {
+        return `Executing \`${command}\``;
+      }
+    }
   }
 
   /**
@@ -177,6 +229,7 @@ export class WebContainerRunner {
       await instance.mount({[projectFolder]: {directory: files}});
     }
     this.treeUpdateCallback();
+    this.progressWritable.set({currentStep: 2, totalSteps: 3 + commands.length, label: this.getCommandLabel(commands[0])});
     this.commands.next({queue: commands, cwd: projectFolder});
     this.watcher = instance.fs.watch(`/${projectFolder}`, {encoding: 'utf8'}, this.treeUpdateCallback);
   }