Introduce component registry for advanced ui settings screen (elastic…

…#22315) (elastic#22391)

* introduce component registry for advanced ui settings screen

src/core_plugins/kibana/public/management/sections/settings/__snapshots__/advanced_settings.test.js.snap

@@ -17,15 +17,7 @@ exports[`AdvancedSettings should render normally 1`] = `
       component="div"
       grow={true}
     >
-      <EuiText
-        grow={true}
-      >
-        <h1
-          data-test-subj="managementSettingsTitle"
-        >
-          Settings
-        </h1>
-      </EuiText>
+      <advanced_settings_page_title />
     </EuiFlexItem>
     <EuiFlexItem
       component="div"
@@ -331,15 +323,7 @@ exports[`AdvancedSettings should render specific setting if given setting key 1`
       component="div"
       grow={true}
     >
-      <EuiText
-        grow={true}
-      >
-        <h1
-          data-test-subj="managementSettingsTitle"
-        >
-          Settings
-        </h1>
-      </EuiText>
+      <advanced_settings_page_title />
     </EuiFlexItem>
     <EuiFlexItem
       component="div"

src/core_plugins/kibana/public/management/sections/settings/advanced_settings.js

@@ -25,7 +25,6 @@ import {
   EuiFlexGroup,
   EuiFlexItem,
   EuiSpacer,
-  EuiText,
   Query,
 } from '@elastic/eui';
 
@@ -36,6 +35,8 @@ import { Form } from './components/form';
 import { getAriaName, toEditableConfig, DEFAULT_CATEGORY } from './lib';
 
 import './advanced_settings.less';
+import { registerDefaultComponents, PAGE_TITLE_COMPONENT } from './components/default_component_registry';
+import { getSettingsComponent } from './components/component_registry';
 
 export class AdvancedSettings extends Component {
   static propTypes = {
@@ -52,16 +53,18 @@ export class AdvancedSettings extends Component {
       query: parsedQuery,
       filteredSettings: this.mapSettings(Query.execute(parsedQuery, this.settings)),
     };
+
+    registerDefaultComponents();
   }
 
   init(config) {
     this.settings = this.mapConfig(config);
     this.groupedSettings = this.mapSettings(this.settings);
 
     this.categories = Object.keys(this.groupedSettings).sort((a, b) => {
-      if(a === DEFAULT_CATEGORY) return -1;
-      if(b === DEFAULT_CATEGORY) return 1;
-      if(a > b) return 1;
+      if (a === DEFAULT_CATEGORY) return -1;
+      if (b === DEFAULT_CATEGORY) return 1;
+      if (a > b) return 1;
       return a === b ? 0 : -1;
     });
 
@@ -133,13 +136,13 @@ export class AdvancedSettings extends Component {
   render() {
     const { filteredSettings, query } = this.state;
 
+    const PageTitle = getSettingsComponent(PAGE_TITLE_COMPONENT);
+
     return (
       <div className="advancedSettings">
         <EuiFlexGroup gutterSize="none">
           <EuiFlexItem>
-            <EuiText>
-              <h1 data-test-subj="managementSettingsTitle">Settings</h1>
-            </EuiText>
+            <PageTitle />
           </EuiFlexItem>
           <EuiFlexItem>
             <Search
@@ -150,7 +153,7 @@ export class AdvancedSettings extends Component {
           </EuiFlexItem>
         </EuiFlexGroup>
         <EuiSpacer size="m" />
-        <CallOuts/>
+        <CallOuts />
         <EuiSpacer size="m" />
         <Form
           settings={filteredSettings}

src/core_plugins/kibana/public/management/sections/settings/components/__snapshots__/component_registry.test.js.snap

@@ -0,0 +1,5 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`getSettingsComponent should throw an error when requesting a component that does not exist 1`] = `"Component not found with id does not exist"`;
+
+exports[`registerSettingsComponent should disallow registering a component with a duplicate id 1`] = `"Component with id test2 is already registered."`;

src/core_plugins/kibana/public/management/sections/settings/components/component_registry.js

@@ -0,0 +1,73 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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.
+ */
+
+const registry = {};
+
+/**
+ * Attempts to register the provided component.
+ * If a component with that ID is already registered, then the registration fails.
+ *
+ * @param {*} id the id of the component to register
+ * @param {*} component the component
+ */
+export function tryRegisterSettingsComponent(id, component) {
+  if (id in registry) {
+    return false;
+  }
+
+  registerSettingsComponent(id, component);
+  return true;
+}
+
+/**
+ * Attempts to register the provided component, with the ability to optionally allow
+ * the component to override an existing one.
+ *
+ * If the intent is to override, then `allowOverride` must be set to true, otherwise an exception is thrown.
+ *
+ * @param {*} id the id of the component to register
+ * @param {*} component the component
+ * @param {*} allowOverride (default: false) - optional flag to allow this component to override a previously registered component
+ */
+export function registerSettingsComponent(id, component, allowOverride = false) {
+  if (!allowOverride && id in registry) {
+    throw new Error(`Component with id ${id} is already registered.`);
+  }
+
+  // Setting a display name if one does not already exist.
+  // This enhances the snapshots, as well as the debugging experience.
+  if (!component.displayName) {
+    component.displayName = id;
+  }
+
+  registry[id] = component;
+}
+
+/**
+ * Retrieve a registered component by its ID.
+ * If the component does not exist, then an exception is thrown.
+ *
+ * @param {*} id the ID of the component to retrieve
+ */
+export function getSettingsComponent(id) {
+  if (!(id in registry)) {
+    throw new Error(`Component not found with id ${id}`);
+  }
+  return registry[id];
+}

src/core_plugins/kibana/public/management/sections/settings/components/component_registry.test.js

@@ -0,0 +1,89 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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 { tryRegisterSettingsComponent, registerSettingsComponent, getSettingsComponent } from './component_registry';
+
+
+describe('tryRegisterSettingsComponent', () => {
+  it('should allow a component to be registered', () => {
+    const component = {};
+    expect(tryRegisterSettingsComponent('tryTest1', component)).toEqual(true);
+  });
+
+  it('should return false if the component is already registered, and not allow an override', () => {
+    const component = {};
+    expect(tryRegisterSettingsComponent('tryTest2', component)).toEqual(true);
+
+    const updatedComponent = { updated: 'yay' };
+    expect(tryRegisterSettingsComponent('tryTest2', updatedComponent)).toEqual(false);
+    expect(getSettingsComponent('tryTest2')).toBe(component);
+  });
+});
+
+describe('registerSettingsComponent', () => {
+  it('should allow a component to be registered', () => {
+    const component = {};
+    registerSettingsComponent('test', component);
+  });
+
+  it('should disallow registering a component with a duplicate id', () => {
+    const component = {};
+    registerSettingsComponent('test2', component);
+    expect(() => registerSettingsComponent('test2', 'some other component')).toThrowErrorMatchingSnapshot();
+  });
+
+  it('should allow a component to be overriden', () => {
+    const component = {};
+    registerSettingsComponent('test3', component);
+
+    const anotherComponent = { 'anotherComponent': 'ok' };
+    registerSettingsComponent('test3', anotherComponent, true);
+
+    expect(getSettingsComponent('test3')).toBe(anotherComponent);
+  });
+
+  it('should set a displayName for the component if one does not exist', () => {
+    const component = {};
+    registerSettingsComponent('display_name_component', component);
+
+    expect(component.displayName).toEqual('display_name_component');
+  });
+
+  it('should not set a displayName for the component if one already exists', () => {
+    const component = {
+      displayName: '<AwesomeComponent>'
+    };
+
+    registerSettingsComponent('another_display_name_component', component);
+
+    expect(component.displayName).toEqual('<AwesomeComponent>');
+  });
+});
+
+describe('getSettingsComponent', () => {
+  it('should allow a component to be retrieved', () => {
+    const component = {};
+    registerSettingsComponent('test4', component);
+    expect(getSettingsComponent('test4')).toBe(component);
+  });
+
+  it('should throw an error when requesting a component that does not exist', () => {
+    expect(() => getSettingsComponent('does not exist')).toThrowErrorMatchingSnapshot();
+  });
+});

src/core_plugins/kibana/public/management/sections/settings/components/default_component_registry.js

@@ -0,0 +1,27 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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 { tryRegisterSettingsComponent } from './component_registry';
+import { PageTitle } from './page_title';
+
+export const PAGE_TITLE_COMPONENT = 'advanced_settings_page_title';
+
+export function registerDefaultComponents() {
+  tryRegisterSettingsComponent(PAGE_TITLE_COMPONENT, PageTitle);
+}

src/core_plugins/kibana/public/management/sections/settings/components/default_component_registry.test.js

@@ -0,0 +1,43 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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 { registerDefaultComponents, PAGE_TITLE_COMPONENT } from './default_component_registry';
+import { getSettingsComponent, registerSettingsComponent } from './component_registry';
+import { PageTitle } from './page_title';
+
+describe('default_component_registry', () => {
+  it('should register default components with the registry', () => {
+    registerDefaultComponents();
+    expect(getSettingsComponent(PAGE_TITLE_COMPONENT)).toEqual(PageTitle);
+  });
+
+  it('should be able to call "registerDefaultComponents" several times without throwing', () => {
+    registerDefaultComponents();
+    registerDefaultComponents();
+    registerDefaultComponents();
+  });
+
+  it('should not override components if they are already registered', () => {
+    const newComponent = {};
+    registerSettingsComponent(PAGE_TITLE_COMPONENT, newComponent, true);
+    registerDefaultComponents();
+
+    expect(getSettingsComponent(PAGE_TITLE_COMPONENT)).toEqual(newComponent);
+  });
+});

src/core_plugins/kibana/public/management/sections/settings/components/page_title/__snapshots__/page_title.test.js.snap

@@ -0,0 +1,13 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`PageTitle should render normally 1`] = `
+<EuiText
+  grow={true}
+>
+  <h1
+    data-test-subj="managementSettingsTitle"
+  >
+    Settings
+  </h1>
+</EuiText>
+`;

src/core_plugins/kibana/public/management/sections/settings/components/page_title/index.js

@@ -0,0 +1,20 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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.
+ */
+
+export { PageTitle } from './page_title';