[Enterprise Search] Set up Workplace Search header action menu, creat…

…e reusable renderHeaderActions (elastic#78050) (elastic#78099)

* Create reusable renderHeaderActions

- I put it in the same file as renderApp, since both functions behave similarly (one renders in the main Kibana app/body, the other renders in Kibana's header)

- slightly opinionated: renamed renderActionMenu to renderHeaderActions from Kibana's examples

* Add example renderHeaderActions usage

* Add example WorkplaceSearchHeaderActions component

- not sure if this should be where it lives or is exported from, feel free to change @scottybollinger

* Update WorkplaceSearchHeaderActions with realistic functionality

- pass required externalUrl helper as arg/prop
- TODO: Consider refactoring KibanaContext to a Kea store so that we can share it across our renderApp and renderHeaderActions

* Fix type errors

x-pack/plugins/enterprise_search/public/applications/index.test.tsx

@@ -10,7 +10,7 @@ import { AppMountParameters } from 'src/core/public';
 import { coreMock } from 'src/core/public/mocks';
 import { licensingMock } from '../../../licensing/public/mocks';
 
-import { renderApp } from './';
+import { renderApp, renderHeaderActions } from './';
 import { AppSearch } from './app_search';
 import { WorkplaceSearch } from './workplace_search';
 
@@ -33,6 +33,7 @@ describe('renderApp', () => {
 
     const unmount = renderApp(MockApp, params, core, plugins, config, data);
     expect(params.element.querySelector('.hello-world')).not.toBeNull();
+
     unmount();
     expect(params.element.innerHTML).toEqual('');
   });
@@ -47,3 +48,16 @@ describe('renderApp', () => {
     expect(params.element.querySelector('.setupGuide')).not.toBeNull();
   });
 });
+
+describe('renderHeaderActions', () => {
+  it('mounts and unmounts any HeaderActions component', () => {
+    const mockHeaderEl = document.createElement('header');
+    const MockHeaderActions = () => <button className="hello-world">Hello World</button>;
+
+    const unmount = renderHeaderActions(MockHeaderActions, mockHeaderEl, {} as any);
+    expect(mockHeaderEl.querySelector('.hello-world')).not.toBeNull();
+
+    unmount();
+    expect(mockHeaderEl.innerHTML).toEqual('');
+  });
+});

x-pack/plugins/enterprise_search/public/applications/index.tsx

@@ -88,3 +88,22 @@ export const renderApp = (
     ReactDOM.unmountComponentAtNode(params.element);
   };
 };
+
+/**
+ * Render function for Kibana's header action menu chrome -
+ * reusable by any Enterprise Search plugin simply by passing in
+ * a custom HeaderActions component (e.g., WorkplaceSearchHeaderActions)
+ * @see https://github.com/elastic/kibana/blob/master/docs/development/core/public/kibana-plugin-core-public.appmountparameters.setheaderactionmenu.md
+ */
+interface IHeaderActionsProps {
+  externalUrl: IExternalUrl;
+}
+
+export const renderHeaderActions = (
+  HeaderActions: React.FC<IHeaderActionsProps>,
+  kibanaHeaderEl: HTMLElement,
+  externalUrl: IExternalUrl
+) => {
+  ReactDOM.render(<HeaderActions externalUrl={externalUrl} />, kibanaHeaderEl);
+  return () => ReactDOM.unmountComponentAtNode(kibanaHeaderEl);
+};

x-pack/plugins/enterprise_search/public/applications/workplace_search/components/layout/index.ts

@@ -5,3 +5,4 @@
  */
 
 export { WorkplaceSearchNav } from './nav';
+export { WorkplaceSearchHeaderActions } from './kibana_header_actions';

x-pack/plugins/enterprise_search/public/applications/workplace_search/components/layout/kibana_header_actions.test.tsx

@@ -0,0 +1,29 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import React from 'react';
+import { shallow } from 'enzyme';
+
+import { EuiButtonEmpty } from '@elastic/eui';
+import { ExternalUrl } from '../../../shared/enterprise_search_url';
+
+import { WorkplaceSearchHeaderActions } from './';
+
+describe('WorkplaceSearchHeaderActions', () => {
+  const externalUrl = new ExternalUrl('http://localhost:3002');
+
+  it('renders a link to the search application', () => {
+    const wrapper = shallow(<WorkplaceSearchHeaderActions externalUrl={externalUrl} />);
+
+    expect(wrapper.find(EuiButtonEmpty).prop('href')).toEqual('http://localhost:3002/ws/search');
+  });
+
+  it('does not render without an Enterprise Search host URL set', () => {
+    const wrapper = shallow(<WorkplaceSearchHeaderActions externalUrl={{} as any} />);
+
+    expect(wrapper.isEmptyRender()).toBe(true);
+  });
+});

x-pack/plugins/enterprise_search/public/applications/workplace_search/components/layout/kibana_header_actions.tsx

@@ -0,0 +1,28 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import React from 'react';
+import { i18n } from '@kbn/i18n';
+import { EuiButtonEmpty } from '@elastic/eui';
+
+import { IExternalUrl } from '../../../shared/enterprise_search_url';
+
+interface IProps {
+  externalUrl: IExternalUrl;
+}
+
+export const WorkplaceSearchHeaderActions: React.FC<IProps> = ({ externalUrl }) => {
+  const { enterpriseSearchUrl, getWorkplaceSearchUrl } = externalUrl;
+  if (!enterpriseSearchUrl) return null;
+
+  return (
+    <EuiButtonEmpty href={getWorkplaceSearchUrl('/search')} target="_blank" iconType="search">
+      {i18n.translate('xpack.enterpriseSearch.workplaceSearch.headerActions.searchApplication', {
+        defaultMessage: 'Go to search application',
+      })}
+    </EuiButtonEmpty>
+  );
+};

x-pack/plugins/enterprise_search/public/plugin.ts

@@ -103,9 +103,16 @@ export class EnterpriseSearchPlugin implements Plugin {
 
         await this.getInitialData(coreStart.http);
 
-        const { renderApp } = await import('./applications');
+        const { renderApp, renderHeaderActions } = await import('./applications');
         const { WorkplaceSearch } = await import('./applications/workplace_search');
 
+        const { WorkplaceSearchHeaderActions } = await import(
+          './applications/workplace_search/components/layout'
+        );
+        params.setHeaderActionMenu((element) =>
+          renderHeaderActions(WorkplaceSearchHeaderActions, element, this.data.externalUrl)
+        );
+
         return renderApp(WorkplaceSearch, params, coreStart, plugins, this.config, this.data);
       },
     });