docs: add copy buttons to markdown code blocks

Add copy functionality to all code blocks in documentation markdown content.
Previously, only example viewer code and module import snippets had copy
buttons, but regular markdown code blocks (like configuration examples)
were missing this feature.

Author: MeAkib

docs/src/app/shared/doc-viewer/code-block-copy-button/code-block-copy-button.ts

@@ -0,0 +1,39 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+import {Component, inject} from '@angular/core';
+import {MatIconButton} from '@angular/material/button';
+import {MatIcon} from '@angular/material/icon';
+import {MatSnackBar} from '@angular/material/snack-bar';
+import {MatTooltip} from '@angular/material/tooltip';
+import {Clipboard} from '@angular/cdk/clipboard';
+
+@Component({
+  selector: 'code-block-copy-button',
+  imports: [MatIconButton, MatIcon, MatTooltip],
+  template: `
+    <button type="button" mat-icon-button matTooltip="Copy code to the clipboard" (click)="copy()">
+      <mat-icon>content_copy</mat-icon>
+    </button>
+  `,
+})
+export class CodeBlockCopyButton {
+  private _clipboard = inject(Clipboard);
+  private _snackbar = inject(MatSnackBar);
+
+  /** Code snippet that will be copied */
+  code = '';
+
+  copy(): void {
+    const message = this._clipboard.copy(this.code)
+      ? 'Copied code snippet'
+      : 'Failed to copy code snippet';
+
+    this._snackbar.open(message, undefined, {duration: 2500});
+  }
+}

docs/src/app/shared/doc-viewer/doc-viewer.spec.ts

@@ -211,6 +211,41 @@ describe('DocViewer', () => {
     expect(clipboardSpy.copy).toHaveBeenCalled();
   });
 
+  it('should show copy icon button for code blocks', () => {
+    const fixture = TestBed.createComponent(DocViewerTestComponent);
+    fixture.componentInstance.documentUrl = `http://material.angular.io/doc-with-code-block.html`;
+    fixture.detectChanges();
+
+    const url = fixture.componentInstance.documentUrl;
+    http.expectOne(url).flush(FAKE_DOCS[url]);
+
+    const docViewer = fixture.debugElement.query(By.directive(DocViewer));
+    expect(docViewer).not.toBeNull();
+
+    // Query all copy buttons within code blocks
+    const iconButtons = fixture.debugElement.queryAll(By.directive(MatIconButton));
+    // At least one icon button for copying code should exist
+    expect(iconButtons.length).toBeGreaterThan(0);
+
+    // Click on the first icon button to trigger copying the code
+    iconButtons[0].nativeNode.dispatchEvent(new MouseEvent('click'));
+    fixture.detectChanges();
+    expect(clipboardSpy.copy).toHaveBeenCalledWith('const example = "test code";');
+  });
+
+  it('should create copy buttons for multiple code blocks', () => {
+    const fixture = TestBed.createComponent(DocViewerTestComponent);
+    fixture.componentInstance.documentUrl = `http://material.angular.io/doc-with-multiple-code-blocks.html`;
+    fixture.detectChanges();
+
+    const url = fixture.componentInstance.documentUrl;
+    http.expectOne(url).flush(FAKE_DOCS[url]);
+
+    const iconButtons = fixture.debugElement.queryAll(By.directive(MatIconButton));
+    // Should have 3 copy buttons for 3 code blocks
+    expect(iconButtons.length).toBe(3);
+  });
+
   // TODO(mmalerba): Add test that example-viewer is instantiated.
 });
 
@@ -262,6 +297,10 @@ const FAKE_DOCS: {[key: string]: string} = {
         data-docs-api-module-import-button="import {MatIconModule} from '@angular/material/icon';">
       </div>
     </div>`,
+  'http://material.angular.io/doc-with-code-block.html': `
+    <div class="docs-markdown">
+      <pre><code>const example = "test code";</code></pre>
+    </div>`,
 };
 
 @Component({

docs/src/app/shared/doc-viewer/doc-viewer.ts

@@ -38,6 +38,7 @@ import {ExampleViewer} from '../example-viewer/example-viewer';
 import {HeaderLink} from './header-link';
 import {DeprecatedFieldComponent} from './deprecated-tooltip';
 import {ModuleImportCopyButton} from './module-import-copy-button';
+import {CodeBlockCopyButton} from './code-block-copy-button/code-block-copy-button';
 
 @Injectable({providedIn: 'root'})
 class DocFetcher {
@@ -160,6 +161,9 @@ export class DocViewer implements OnDestroy {
     // Create icon buttons to copy module import
     this._createCopyIconForModule();
 
+    // Create icon button for code block
+    this._createCopyButtonsForCodeBlocks();
+
     // Resolving and creating components dynamically in Angular happens synchronously, but since
     // we want to emit the output if the components are actually rendered completely, we wait
     // until the Angular zone becomes stable.
@@ -267,4 +271,30 @@ export class DocViewer implements OnDestroy {
       this._portalHosts.push(elementPortalOutlet);
     });
   }
+
+  _createCopyButtonsForCodeBlocks() {
+    // Query all <pre> tags that contain <code> elements (markdown code blocks)
+    const codeBlockElements = this._elementRef.nativeElement.querySelectorAll(
+      '.docs-markdown pre:has(code)',
+    );
+
+    [...codeBlockElements].forEach((element: HTMLElement) => {
+      // Extract the text content from the code block
+      const codeElement = element.querySelector('code');
+      const codeSnippet = codeElement?.textContent || '';
+
+      const elementPortalOutlet = new DomPortalOutlet(element, this._appRef, this._injector);
+      const codeBlockCopyButtonPortal = new ComponentPortal(
+        CodeBlockCopyButton,
+        this._viewContainerRef,
+      );
+      const codeBlockCopyButtonOutlet = elementPortalOutlet.attach(codeBlockCopyButtonPortal);
+
+      if (codeSnippet) {
+        codeBlockCopyButtonOutlet.instance.code = codeSnippet;
+      }
+
+      this._portalHosts.push(elementPortalOutlet);
+    });
+  }
 }

docs/src/styles/_markdown.scss

@@ -72,15 +72,21 @@
       overflow-x: auto;
       padding: 20px;
       white-space: pre-wrap;
-
       border: solid 1px var(--mat-sys-outline-variant);
       border-radius: 12px;
+      position: relative;
 
       code {
         background: transparent;
         padding: 0;
         font-size: 100%;
       }
+
+      code-block-copy-button {
+        position: absolute;
+        top: 5px;
+        right: 5px;
+      }
     }
 
     code {