Merge pull request #2017 from hashicorp/02-popover-register-event-mod…

…ifier

`RichTooltip/Popover` component - `hds-register-event` modifier [02]

.changeset/afraid-beds-serve.md

@@ -0,0 +1,5 @@
+---
+"@hashicorp/design-system-components": minor
+---
+
+Added `hds-register-event` modifier (for internal use)

packages/components/package.json

@@ -258,6 +258,7 @@
       "./helpers/hds-link-to-query.js": "./dist/_app_/helpers/hds-link-to-query.js",
       "./modifiers/hds-anchored-position.js": "./dist/_app_/modifiers/hds-anchored-position.js",
       "./modifiers/hds-clipboard.js": "./dist/_app_/modifiers/hds-clipboard.js",
+      "./modifiers/hds-register-event.js": "./dist/_app_/modifiers/hds-register-event.js",
       "./modifiers/hds-tooltip.js": "./dist/_app_/modifiers/hds-tooltip.js"
     }
   },

packages/components/src/modifiers/hds-register-event.js

@@ -0,0 +1,30 @@
+import { modifier } from 'ember-modifier';
+
+// Notice: we use a function-based modifier here instead of a class-based one
+// because it's quite simple in its logic, and doesn't require injecting services
+// see: https://github.com/ember-modifier/ember-modifier#function-based-modifiers
+
+// this modifier is a "replacement" of the standard `{{on 'event' myFunction}}`
+// it's needed because the {{on}} modifier can't be applied conditionally, apparently
+// see: https://github.com/emberjs/ember.js/issues/19869#issuecomment-1909118910
+// see: https://github.com/emberjs/ember.js/pull/20629
+// see also: https://github.com/emberjs/ember.js/blob/main/packages/%40ember/-internals/glimmer/lib/modifiers/on.ts#L30
+export default modifier((element, positional, named = {}) => {
+  // the "target" element the listeners are added to
+  // notice: this is the element the Ember modifier is attached to
+  const targetElement = element;
+  // the event name and handler to apply to the element
+  // notice: it's expressed as "positional" argument (array) for the modifier
+  const [event, eventHandler] = positional;
+  // the options for the `addEventListener()` method
+  // see: https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener
+  // notice: it's expressed as "named" argument (object) for the modifier
+  const { useCapture = false } = named;
+
+  targetElement.addEventListener(event, eventHandler, useCapture);
+
+  // this (teardown) function is run when the element is removed from the DOM
+  return () => {
+    targetElement.removeEventListener(event, eventHandler, useCapture);
+  };
+});

showcase/tests/integration/modifiers/hds-register-event-test.js

@@ -0,0 +1,45 @@
+/**
+ * Copyright (c) HashiCorp, Inc.
+ * SPDX-License-Identifier: MPL-2.0
+ */
+
+import { module, test } from 'qunit';
+import { setupRenderingTest } from 'ember-qunit';
+import { click, render, triggerEvent } from '@ember/test-helpers';
+import { hbs } from 'ember-cli-htmlbars';
+
+module('Integration | Modifier | hds-register-event', function (hooks) {
+  setupRenderingTest(hooks);
+
+  test('it adds an event listener to the element', async function (assert) {
+    assert.expect(1);
+
+    this.set('eventHandler', () => {
+      assert.ok(true, 'event handler was called');
+    });
+
+    await render(
+      hbs`<button id="test-button" {{hds-register-event 'click' this.eventHandler}}>Test</button>`
+    );
+
+    await click('button');
+  });
+
+  test('it passes the `useCapture` option to the event listener', async function (assert) {
+    assert.expect(1);
+
+    this.set('eventHandler', (event) => {
+      assert.strictEqual(
+        event.eventPhase,
+        Event.CAPTURING_PHASE,
+        'event was captured'
+      );
+    });
+
+    await render(
+      hbs`<button id="test-button" {{hds-register-event 'click' this.eventHandler useCapture=true}}><span>Test</span></button>`
+    );
+
+    await triggerEvent('span', 'click', { bubbles: true });
+  });
+});