docs(material/chips): describe how to use chips in forms

Added a description and examples in the docs of how to use chips in both reactive and template-driven forms.

Fixes angular#22906

src/components-examples/material/chips/chips-reactive-form/chips-reactive-form-example.css

@@ -0,0 +1,3 @@
+.example-form-field {
+    width: 100%;
+}

src/components-examples/material/chips/chips-reactive-form/chips-reactive-form-example.html

@@ -0,0 +1,21 @@
+<section>
+    <h4>Chips inside of a Reactive form</h4>
+    <mat-form-field class="example-form-field">
+        <mat-label>Video keywords</mat-label>
+        <mat-chip-grid #reactiveChipGrid aria-label="Enter reactive form keywords" [formControl]="formControl">
+        @for (keyword of reactiveKeywords(); track keyword) {
+            <mat-chip-row (removed)="removeReactiveKeyword(keyword)">
+            {{keyword}}
+            <button matChipRemove aria-label="'remove reactive form' + keyword">
+                <mat-icon>cancel</mat-icon>
+            </button>
+            </mat-chip-row>
+        }
+        </mat-chip-grid>
+        <input
+        placeholder="New keyword..."
+        [matChipInputFor]="reactiveChipGrid"
+        (matChipInputTokenEnd)="addReactiveKeyword($event)"
+        />
+    </mat-form-field>
+</section>

src/components-examples/material/chips/chips-reactive-form/chips-reactive-form-example.ts

@@ -0,0 +1,57 @@
+import {LiveAnnouncer} from '@angular/cdk/a11y';
+import {ChangeDetectionStrategy, Component, inject, signal} from '@angular/core';
+import {FormControl, ReactiveFormsModule} from '@angular/forms';
+import {MatButtonModule} from '@angular/material/button';
+import {MatChipInputEvent, MatChipsModule} from '@angular/material/chips';
+import {MatFormFieldModule} from '@angular/material/form-field';
+import {MatIconModule} from '@angular/material/icon';
+
+/**
+ * @title Chips in reactive forms
+ */
+@Component({
+  selector: 'chips-reactive-form-example',
+  templateUrl: 'chips-reactive-form-example.html',
+  styleUrl: 'chips-reactive-form-example.css',
+  standalone: true,
+  imports: [
+    MatButtonModule,
+    MatFormFieldModule,
+    MatChipsModule,
+    ReactiveFormsModule,
+    MatIconModule,
+  ],
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class ChipsReactiveFormExample {
+  readonly reactiveKeywords = signal(['angular', 'how-to', 'tutorial', 'accessibility']);
+  readonly formControl = new FormControl(['angular']);
+
+  announcer = inject(LiveAnnouncer);
+
+  removeReactiveKeyword(keyword: string) {
+    this.reactiveKeywords.update(keywords => {
+      const index = keywords.indexOf(keyword);
+      if (index < 0) {
+        return keywords;
+      }
+
+      keywords.splice(index, 1);
+      this.announcer.announce(`removed ${keyword} from reactive form`);
+      return [...keywords];
+    });
+  }
+
+  addReactiveKeyword(event: MatChipInputEvent): void {
+    const value = (event.value || '').trim();
+
+    // Add our keyword
+    if (value) {
+      this.reactiveKeywords.update(keywords => [...keywords, value]);
+      this.announcer.announce(`added ${value} to reactive form`);
+    }
+
+    // Clear the input value
+    event.chipInput!.clear();
+  }
+}

src/components-examples/material/chips/chips-template-form/chips-template-form-example.css

@@ -0,0 +1,3 @@
+.example-form-field {
+    width: 100%;
+}

src/components-examples/material/chips/chips-template-form/chips-template-form-example.html

@@ -0,0 +1,21 @@
+<section>
+    <h4>Chips inside of a Template-driven form</h4>
+    <mat-form-field class="example-form-field">
+        <mat-label>Video keywords</mat-label>
+        <mat-chip-grid #templateChipGrid aria-label="Enter template form keywords" [(ngModel)]="templateKeywords">
+        @for (keyword of templateKeywords(); track keyword) {
+            <mat-chip-row (removed)="removeTemplateKeyword(keyword)">
+            {{keyword}}
+            <button matChipRemove aria-label="'remove template form' + keyword">
+                <mat-icon>cancel</mat-icon>
+            </button>
+            </mat-chip-row>
+        }
+        </mat-chip-grid>
+        <input
+        placeholder="New keyword..."
+        [matChipInputFor]="templateChipGrid"
+        (matChipInputTokenEnd)="addTemplateKeyword($event)"
+        />
+    </mat-form-field>
+</section>

src/components-examples/material/chips/chips-template-form/chips-template-form-example.ts

@@ -0,0 +1,50 @@
+import {LiveAnnouncer} from '@angular/cdk/a11y';
+import {ChangeDetectionStrategy, Component, inject, signal} from '@angular/core';
+import {FormsModule} from '@angular/forms';
+import {MatButtonModule} from '@angular/material/button';
+import {MatChipInputEvent, MatChipsModule} from '@angular/material/chips';
+import {MatFormFieldModule} from '@angular/material/form-field';
+import {MatIconModule} from '@angular/material/icon';
+
+/**
+ * @title Chips in template-driven forms
+ */
+@Component({
+  selector: 'chips-template-form-example',
+  templateUrl: 'chips-template-form-example.html',
+  styleUrl: 'chips-template-form-example.css',
+  standalone: true,
+  imports: [MatButtonModule, MatFormFieldModule, MatChipsModule, FormsModule, MatIconModule],
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class ChipsTemplateFormExample {
+  readonly templateKeywords = signal(['angular', 'how-to', 'tutorial', 'accessibility']);
+
+  announcer = inject(LiveAnnouncer);
+
+  removeTemplateKeyword(keyword: string) {
+    this.templateKeywords.update(keywords => {
+      const index = keywords.indexOf(keyword);
+      if (index < 0) {
+        return keywords;
+      }
+
+      keywords.splice(index, 1);
+      this.announcer.announce(`removed ${keyword} from template form`);
+      return [...keywords];
+    });
+  }
+
+  addTemplateKeyword(event: MatChipInputEvent): void {
+    const value = (event.value || '').trim();
+
+    // Add our keyword
+    if (value) {
+      this.templateKeywords.update(keywords => [...keywords, value]);
+      this.announcer.announce(`added ${value} to template form`);
+    }
+
+    // Clear the input value
+    event.chipInput!.clear();
+  }
+}

src/components-examples/material/chips/index.ts

@@ -5,4 +5,6 @@ export {ChipsOverviewExample} from './chips-overview/chips-overview-example';
 export {ChipsStackedExample} from './chips-stacked/chips-stacked-example';
 export {ChipsHarnessExample} from './chips-harness/chips-harness-example';
 export {ChipsFormControlExample} from './chips-form-control/chips-form-control-example';
+export {ChipsReactiveFormExample} from './chips-reactive-form/chips-reactive-form-example';
+export {ChipsTemplateFormExample} from './chips-template-form/chips-template-form-example';
 export {ChipsAvatarExample} from './chips-avatar/chips-avatar-example';

src/material/chips/chips.md

@@ -40,6 +40,13 @@ Chips are always used inside a container. To create chips connected to an input
 
 <!-- example(chips-input) -->
 
+### Use with `@angular/forms`
+Chips are compatible with `@angular/forms` and supports both `FormsModule`
+and `ReactiveFormsModule`.
+
+<!-- example(chips-template-form-example) -->
+<!-- example(chips-reactive-form-example) -->
+
 #### Disabled `<mat-chip-row>`
 
 Use the `disabled` Input to disable a `<mat-chip-row>`. This gives the `<mat-chip-row>` a disabled appearance and prevents the user from interacting with it.