fix(expandable-section, expandable-text, expandable-panel): Added ari…

…a-controls and aria-expanded.

Fixed an issue where the correct aria attributes where not present on accordion like elements like
expandable-section, expandable-text and expandable-panel.

Fixes #788

libs/barista-components/core/src/common-behaviours/id.spec.ts

@@ -0,0 +1,33 @@
+/**
+ * @license
+ * Copyright 2020 Dynatrace LLC
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { mixinId } from './id';
+
+describe('MixinId', () => {
+  it('should augment an existing class with an property', () => {
+    class EmptyClass {}
+
+    const classWithDisabled = mixinId(EmptyClass, 'dt-mixin-test');
+    const instance = new classWithDisabled();
+
+    // Expected the mixed-into class to have an id property
+    expect(instance.id).toMatch(/dt-mixin-test-\d/);
+
+    instance.id = 'my-id';
+    // Expected the mixed-into class to have an updated id property
+    expect(instance.id).toBe('my-id');
+  });
+});

libs/barista-components/core/src/common-behaviours/id.ts

@@ -0,0 +1,55 @@
+/**
+ * @license
+ * Copyright 2020 Dynatrace LLC
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { Constructor } from './constructor';
+import { isDefined } from '../util';
+
+/**
+ * UniqueId counter, will be incremented with every
+ * instatiation of the ExpandablePanel class
+ */
+let uniqueId = 0;
+
+export interface HasId {
+  /** Represents the unique id of the component. */
+  id: string;
+}
+
+/** Mixin to augment a directive with a `id` property. */
+export function mixinId<T extends Constructor<{}>>(
+  base: T,
+  idPreset: string,
+): Constructor<HasId> & T {
+  return class extends base {
+    /** Sets a unique id for the expandable section. */
+    get id(): string {
+      return this._id;
+    }
+    set id(value: string) {
+      if (isDefined(value)) {
+        this._id = value;
+      } else {
+        this._id = `${idPreset}-${uniqueId++}`;
+      }
+    }
+    private _id = `${idPreset}-${uniqueId++}`;
+
+    // tslint:disable-next-line
+    constructor(...args: any[]) {
+      super(...args); // tslint:disable-line:no-inferred-empty-object-type
+    }
+  };
+}

libs/barista-components/core/src/common-behaviours/index.ts

@@ -21,3 +21,4 @@ export * from './error-state';
 export * from './progress';
 export * from './tabindex';
 export * from './dom-exit';
+export * from './id';

libs/barista-components/expandable-panel/README.md

@@ -34,10 +34,11 @@ element.
 
 ## Inputs
 
-| Name       | Type      | Default | Description                              |
-| ---------- | --------- | ------- | ---------------------------------------- |
-| `expanded` | `boolean` | `false` | Sets or gets the panel's expanded state. |
-| `disabled` | `boolean` | `false` | Sets or gets the panel's disabled state. |
+| Name       | Type      | Default                               | Description                              |
+| ---------- | --------- | ------------------------------------- | ---------------------------------------- |
+| `expanded` | `boolean` | `false`                               | Sets or gets the panel's expanded state. |
+| `disabled` | `boolean` | `false`                               | Sets or gets the panel's disabled state. |
+| `id`       | `string`  | `dt-expandable-panel-{rollingNumber}` | Sets the id of the expandable panel.     |
 
 ## Outputs
 

libs/barista-components/expandable-panel/src/expandable-panel-trigger.ts

@@ -16,7 +16,7 @@
 
 import { DOWN_ARROW, UP_ARROW } from '@angular/cdk/keycodes';
 import { ChangeDetectorRef, Directive, Input, OnDestroy } from '@angular/core';
-import { Subscription } from 'rxjs';
+import { Subscription, merge } from 'rxjs';
 
 import { _readKeyCode } from '@dynatrace/barista-components/core';
 
@@ -33,6 +33,8 @@ import { DtExpandablePanel } from './expandable-panel';
     '[attr.disabled]':
       'dtExpandablePanel && dtExpandablePanel.disabled ? true: null',
     '[attr.aria-disabled]': 'dtExpandablePanel && dtExpandablePanel.disabled',
+    '[attr.aria-expanded]': 'dtExpandablePanel && dtExpandablePanel.expanded',
+    '[attr.aria-controls]': 'dtExpandablePanel && dtExpandablePanel.id',
     '[tabindex]': 'dtExpandablePanel && dtExpandablePanel.disabled ? -1 : 0',
     '(click)': '_handleClick()',
     '(keydown)': '_handleKeydown($event)',
@@ -47,11 +49,12 @@ export class DtExpandablePanelTrigger implements OnDestroy {
   set dtExpandablePanel(value: DtExpandablePanel) {
     this._panel = value;
     this._expandedSubscription.unsubscribe();
-    this._expandedSubscription = this.dtExpandablePanel.expandChange.subscribe(
-      () => {
-        this._changeDetectorRef.markForCheck();
-      },
-    );
+    this._expandedSubscription = merge(
+      this.dtExpandablePanel.expandChange,
+      this.dtExpandablePanel._id,
+    ).subscribe(() => {
+      this._changeDetectorRef.markForCheck();
+    });
   }
   private _panel: DtExpandablePanel;
   private _expandedSubscription: Subscription = Subscription.EMPTY;

libs/barista-components/expandable-panel/src/expandable-panel.spec.ts

@@ -19,7 +19,7 @@
 // tslint:disable deprecation
 
 import { Component, DebugElement } from '@angular/core';
-import { TestBed, async } from '@angular/core/testing';
+import { TestBed, async, ComponentFixture } from '@angular/core/testing';
 import { By } from '@angular/platform-browser';
 import { NoopAnimationsModule } from '@angular/platform-browser/animations';
 
@@ -121,94 +121,150 @@ describe('DtExpandablePanel', () => {
       expect(instanceElement.classList).toContain('dt-expandable-panel-opened');
     });
 
-    // check CSS class of trigger when expanded
-    it('should have correctly styled trigger button when expanded', () => {
-      const panelFixture = createComponent(ExpandablePanelWithTriggerComponent);
-      const panelDebugElement = panelFixture.debugElement.query(
-        By.directive(DtExpandablePanel),
+    // check expanded and expandChange outputs
+    it('should fire expanded and expandChange events on open', () => {
+      const expandedSpy = jest.fn();
+      const changedSpy = jest.fn();
+      const instance = instanceDebugElement.componentInstance;
+      const expandedSubscription = instance._panelExpanded.subscribe(
+        expandedSpy,
       );
-      const triggerInstanceElement = panelFixture.debugElement.query(
+      const changedSubscription = instance.expandChange.subscribe(changedSpy);
+
+      expandablePanelInstance.open();
+      fixture.detectChanges();
+      expect(expandedSpy).toHaveBeenCalled();
+      expect(changedSpy).toHaveBeenCalled();
+
+      expandedSubscription.unsubscribe();
+      changedSubscription.unsubscribe();
+    });
+
+    // check collapsed and expandChange outputs
+    it('should fire collapsed and expandChange events on close', () => {
+      expandablePanelInstance.expanded = true;
+      const collapsedSpy = jest.fn();
+      const changedSpy = jest.fn();
+      const instance = instanceDebugElement.componentInstance;
+      const collapsedSubscription = instance._panelCollapsed.subscribe(
+        collapsedSpy,
+      );
+      const changedSubscription = instance.expandChange.subscribe(changedSpy);
+
+      expandablePanelInstance.close();
+      fixture.detectChanges();
+      expect(collapsedSpy).toHaveBeenCalled();
+      expect(changedSpy).toHaveBeenCalled();
+
+      collapsedSubscription.unsubscribe();
+      changedSubscription.unsubscribe();
+    });
+  });
+
+  describe('dt-expandable-panel with trigger', () => {
+    let fixture: ComponentFixture<ExpandablePanelWithTriggerComponent>;
+    let triggerInstanceElement: HTMLElement;
+    let panelDebugElement: DebugElement;
+    let panelInstance: DtExpandablePanel;
+    let panelInstanceElement: HTMLElement;
+
+    beforeEach(() => {
+      fixture = createComponent(ExpandablePanelWithTriggerComponent);
+      triggerInstanceElement = fixture.debugElement.query(
         By.css('.dt-expandable-panel-trigger'),
       ).nativeElement;
-      const panelInstance = panelDebugElement.injector.get<DtExpandablePanel>(
-        DtExpandablePanel,
+      panelInstance = fixture.debugElement.query(
+        By.directive(DtExpandablePanel),
+      ).componentInstance;
+      panelDebugElement = fixture.debugElement.query(
+        By.directive(DtExpandablePanel),
       );
+      panelInstanceElement = panelDebugElement.nativeElement;
+    });
 
+    // check CSS class of trigger when expanded
+    it('should have correctly styled trigger button when expanded', () => {
       expect(triggerInstanceElement.classList).toContain(
         'dt-expandable-panel-trigger',
       );
       expect(triggerInstanceElement.classList).not.toContain(
         'dt-expandable-panel-trigger-open',
       );
       panelInstance.expanded = true;
-      panelFixture.detectChanges();
+      fixture.detectChanges();
       expect(triggerInstanceElement.classList).toContain(
         'dt-expandable-panel-trigger-open',
       );
     });
 
     // check attributes of panel and trigger when disabled
     it('should have correct attributes when disabled', () => {
-      const panelFixture = createComponent(ExpandablePanelWithTriggerComponent);
-      const panelDebugElement = panelFixture.debugElement.query(
-        By.directive(DtExpandablePanel),
-      );
-      const triggerInstanceElement = panelFixture.debugElement.query(
-        By.css('.dt-expandable-panel-trigger'),
-      ).nativeElement;
-      const panelInstanceElement = panelDebugElement.nativeElement;
-      const panelInstance = panelDebugElement.injector.get<DtExpandablePanel>(
-        DtExpandablePanel,
-      );
-
       expect(panelInstanceElement.getAttribute('aria-disabled')).toBe('false');
       expect(triggerInstanceElement.getAttribute('tabindex')).toBe('0');
       expect(triggerInstanceElement.getAttribute('disabled')).toBe(null);
 
       panelInstance.disabled = true;
-      panelFixture.detectChanges();
+      fixture.detectChanges();
       expect(panelInstanceElement.getAttribute('aria-disabled')).toBe('true');
       expect(triggerInstanceElement.getAttribute('tabindex')).toBe('-1');
       expect(triggerInstanceElement.getAttribute('disabled')).toBe('true');
     });
 
-    // check expanded and expandChange outputs
-    it('should fire expanded and expandChange events on open', () => {
-      const expandedSpy = jest.fn();
-      const changedSpy = jest.fn();
-      const instance = instanceDebugElement.componentInstance;
-      const expandedSubscription = instance._panelExpanded.subscribe(
-        expandedSpy,
+    // check aria-controls attribute
+    it('should have the correct aria-controls attribute', () => {
+      expect(triggerInstanceElement.getAttribute('aria-controls')).toMatch(
+        /dt-expandable-panel-\d/,
       );
-      const changedSubscription = instance.expandChange.subscribe(changedSpy);
+    });
 
-      expandablePanelInstance.open();
+    // check aria-controls attribute
+    it('should have the correct aria-controls attribute when using ID input', () => {
+      fixture.componentInstance.id = 'my-panel';
       fixture.detectChanges();
-      expect(expandedSpy).toHaveBeenCalled();
-      expect(changedSpy).toHaveBeenCalled();
 
-      expandedSubscription.unsubscribe();
-      changedSubscription.unsubscribe();
+      triggerInstanceElement = fixture.debugElement.query(
+        By.css('.dt-expandable-panel-trigger'),
+      ).nativeElement;
+      panelInstanceElement = fixture.debugElement.query(
+        By.css('.dt-expandable-panel'),
+      ).nativeElement;
+
+      expect(panelInstanceElement.getAttribute('id')).toBe('my-panel');
+      expect(triggerInstanceElement.getAttribute('aria-controls')).toBe(
+        'my-panel',
+      );
     });
 
-    // check collapsed and expandChange outputs
-    it('should fire collapsed and expandChange events on close', () => {
-      expandablePanelInstance.expanded = true;
-      const collapsedSpy = jest.fn();
-      const changedSpy = jest.fn();
-      const instance = instanceDebugElement.componentInstance;
-      const collapsedSubscription = instance._panelCollapsed.subscribe(
-        collapsedSpy,
+    // check aria-controls attribute
+    it('should fall back to the default id when ID is unset', () => {
+      fixture.componentInstance.id = 'my-panel';
+      fixture.detectChanges();
+
+      fixture.componentInstance.id = null;
+      fixture.detectChanges();
+
+      triggerInstanceElement = fixture.debugElement.query(
+        By.css('.dt-expandable-panel-trigger'),
+      ).nativeElement;
+
+      expect(triggerInstanceElement.getAttribute('aria-controls')).toMatch(
+        /dt-expandable-panel-\d/,
       );
-      const changedSubscription = instance.expandChange.subscribe(changedSpy);
+    });
 
-      expandablePanelInstance.close();
+    // check if it has the correct aria-expanded attribute
+    it('should have the correct aria-expanded attribute', () => {
+      expect(triggerInstanceElement.getAttribute('aria-expanded')).toBe(
+        'false',
+      );
+    });
+
+    // check if it has the correct aria-expanded attribute is set after expanding
+    it('should have the correct aria-expanded attribute after opening the expandable', () => {
+      panelInstance.expanded = true;
       fixture.detectChanges();
-      expect(collapsedSpy).toHaveBeenCalled();
-      expect(changedSpy).toHaveBeenCalled();
 
-      collapsedSubscription.unsubscribe();
-      changedSubscription.unsubscribe();
+      expect(triggerInstanceElement.getAttribute('aria-expanded')).toBe('true');
     });
   });
 });
@@ -224,8 +280,10 @@ class ExpandablePanelComponent {}
 @Component({
   selector: 'dt-test-app',
   template: `
-    <dt-expandable-panel #panel>text</dt-expandable-panel>
+    <dt-expandable-panel #panel [id]="id">text</dt-expandable-panel>
     <button [dtExpandablePanel]="panel">trigger</button>
   `,
 })
-class ExpandablePanelWithTriggerComponent {}
+class ExpandablePanelWithTriggerComponent {
+  id: string | null;
+}