fix(material/chips): chip set overwriting disabled state (angular#29795)

The chip set has been set up in a way where it syncs its state to the chips, instead of the other way around which we follow in other components. This means that if its `disabled` state changes later, it can ovewrite the state that the user explicitly set on the chip.

These changes make the logic a bit more robust by writing to a different field.

Fixes angular#29783.

Author: crisbeto

src/material/chips/chip-listbox.spec.ts

@@ -113,6 +113,15 @@ describe('MatChipListbox', () => {
         expect(chipListboxNativeElement.hasAttribute('role')).toBe(false);
         expect(chipListboxNativeElement.hasAttribute('aria-required')).toBe(false);
       });
+
+      it('should toggle the chips disabled state based on whether it is disabled', fakeAsync(() => {
+        fixture.destroy();
+        TestBed.resetTestingModule();
+        const disabledFixture = createComponent(IndividuallyDisabledChipInsideForm);
+        disabledFixture.detectChanges();
+        flush();
+        expect(disabledFixture.componentInstance.chip.disabled).toBe(true);
+      }));
     });
 
     describe('with selected chips', () => {
@@ -1043,3 +1052,17 @@ class FalsyBasicChipListbox {
   @ViewChild(MatChipListbox) chipListbox: MatChipListbox;
   @ViewChildren(MatChipOption) chips: QueryList<MatChipOption>;
 }
+
+// Based on #29783.
+@Component({
+  template: `
+    <form>
+      <mat-chip-listbox name="test" [ngModel]="null">
+        <mat-chip-option value="1" disabled>Hello</mat-chip-option>
+      </mat-chip-listbox>
+    </form>
+  `,
+})
+class IndividuallyDisabledChipInsideForm {
+  @ViewChild(MatChipOption) chip: MatChipOption;
+}

src/material/chips/chip-set.ts

@@ -158,12 +158,10 @@ export class MatChipSet implements AfterViewInit, OnDestroy {
 
   /** Syncs the chip-set's state with the individual chips. */
   protected _syncChipsState() {
-    if (this._chips) {
-      this._chips.forEach(chip => {
-        chip.disabled = this._disabled;
-        chip._changeDetectorRef.markForCheck();
-      });
-    }
+    this._chips?.forEach(chip => {
+      chip._chipListDisabled = this._disabled;
+      chip._changeDetectorRef.markForCheck();
+    });
   }
 
   /** Dummy method for subclasses to override. Base chip set cannot be focused. */

src/material/chips/chip.ts

@@ -158,6 +158,9 @@ export class MatChip implements OnInit, AfterViewInit, AfterContentInit, DoCheck
   /** Id of a span that contains this chip's aria description. */
   _ariaDescriptionId = `${this.id}-aria-description`;
 
+  /** Whether the chip list is disabled. */
+  _chipListDisabled: boolean = false;
+
   private _textElement!: HTMLElement;
 
   /**
@@ -201,7 +204,13 @@ export class MatChip implements OnInit, AfterViewInit, AfterContentInit, DoCheck
 
   /** Whether the chip is disabled. */
   @Input({transform: booleanAttribute})
-  disabled: boolean = false;
+  get disabled(): boolean {
+    return this._disabled || this._chipListDisabled;
+  }
+  set disabled(value: boolean) {
+    this._disabled = value;
+  }
+  private _disabled = false;
 
   /** Emitted when a chip is to be removed. */
   @Output() readonly removed: EventEmitter<MatChipEvent> = new EventEmitter<MatChipEvent>();

tools/public_api_guard/material/chips.md

@@ -58,9 +58,11 @@ export class MatChip implements OnInit, AfterViewInit, AfterContentInit, DoCheck
     protected basicChipAttrName: string;
     // (undocumented)
     _changeDetectorRef: ChangeDetectorRef;
+    _chipListDisabled: boolean;
     color?: string | null;
     readonly destroyed: EventEmitter<MatChipEvent>;
-    disabled: boolean;
+    get disabled(): boolean;
+    set disabled(value: boolean);
     disableRipple: boolean;
     // (undocumented)
     protected _document: Document;