[lens] Native renderer

x-pack/plugins/lens/public/app_plugin/app.tsx

@@ -5,23 +5,18 @@
  */
 
 import { I18nProvider } from '@kbn/i18n/react';
-import React, { useCallback } from 'react';
+import React from 'react';
 
 import { EditorFrameSetup } from '../types';
+import { NativeRenderer } from '../native_renderer';
 
 export function App({ editorFrame }: { editorFrame: EditorFrameSetup }) {
-  const renderFrame = useCallback(node => {
-    if (node !== null) {
-      editorFrame.render(node);
-    }
-  }, []);
-
   return (
     <I18nProvider>
       <div>
         <h1>Lens</h1>
 
-        <div ref={renderFrame} />
+        <NativeRenderer render={editorFrame.render} nativeProps={undefined} />
       </div>
     </I18nProvider>
   );

x-pack/plugins/lens/public/editor_frame_plugin/editor_frame.tsx

@@ -6,6 +6,7 @@
 
 import React, { useReducer, useEffect } from 'react';
 import { Datasource, Visualization } from '../types';
+import { NativeRenderer } from '../native_renderer';
 
 interface EditorFrameProps {
   datasources: { [key: string]: Datasource };
@@ -81,41 +82,35 @@ export function EditorFrame(props: EditorFrameProps) {
     <div>
       <h2>Editor Frame</h2>
 
-      <div
-        ref={domElement => {
-          if (domElement) {
-            props.datasources[state.datasourceName].renderDataPanel(domElement, {
-              state: state.datasourceState,
-              setState: newState =>
-                dispatch({
-                  type: 'UPDATE_DATASOURCE',
-                  payload: newState,
-                }),
-            });
-          }
+      <NativeRenderer
+        render={props.datasources[state.datasourceName].renderDataPanel}
+        nativeProps={{
+          state: state.datasourceState,
+          setState: (newState: any) =>
+            dispatch({
+              type: 'UPDATE_DATASOURCE',
+              payload: newState,
+            }),
         }}
       />
 
-      <div
-        ref={domElement => {
-          if (domElement) {
-            props.visualizations[state.visualizationName].renderConfigPanel(domElement, {
-              datasource: props.datasources[state.datasourceName].getPublicAPI(
-                state.datasourceState,
-                newState =>
-                  dispatch({
-                    type: 'UPDATE_DATASOURCE',
-                    payload: newState,
-                  })
-              ),
-              state: state.visualizationState,
-              setState: newState =>
-                dispatch({
-                  type: 'UPDATE_VISUALIZATION',
-                  payload: newState,
-                }),
-            });
-          }
+      <NativeRenderer
+        render={props.visualizations[state.visualizationName].renderConfigPanel}
+        nativeProps={{
+          datasource: props.datasources[state.datasourceName].getPublicAPI(
+            state.datasourceState,
+            newState =>
+              dispatch({
+                type: 'UPDATE_DATASOURCE',
+                payload: newState,
+              })
+          ),
+          state: state.visualizationState,
+          setState: (newState: any) =>
+            dispatch({
+              type: 'UPDATE_VISUALIZATION',
+              payload: newState,
+            }),
         }}
       />
     </div>

x-pack/plugins/lens/public/index.ts

@@ -6,8 +6,8 @@
 
 export * from './types';
 
-import { IScope } from 'angular';
 import { render, unmountComponentAtNode } from 'react-dom';
+import { IScope } from 'angular';
 import chrome from 'ui/chrome';
 import { appSetup, appStop } from './app_plugin';
 

x-pack/plugins/lens/public/native_renderer/index.ts

@@ -0,0 +1,7 @@
+/*
+ * 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.
+ */
+
+export * from './native_renderer';

x-pack/plugins/lens/public/native_renderer/native_renderer.test.tsx

@@ -0,0 +1,187 @@
+/*
+ * 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 { render } from 'react-dom';
+import { NativeRenderer } from './native_renderer';
+import { act } from 'react-dom/test-utils';
+
+function renderAndTriggerHooks(element: JSX.Element, mountpoint: Element) {
+  // act takes care of triggering state hooks
+  act(() => {
+    render(element, mountpoint);
+  });
+}
+
+describe('native_renderer', () => {
+  let mountpoint: Element;
+
+  beforeEach(() => {
+    mountpoint = document.createElement('div');
+  });
+
+  afterEach(() => {
+    mountpoint.remove();
+  });
+
+  it('should render element in container', () => {
+    const renderSpy = jest.fn();
+    const testProps = { a: 'abc' };
+
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={testProps} />,
+      mountpoint
+    );
+    const containerElement = mountpoint.firstElementChild;
+    expect(renderSpy).toHaveBeenCalledWith(containerElement, testProps);
+  });
+
+  it('should not render again if props do not change', () => {
+    const renderSpy = jest.fn();
+    const testProps = { a: 'abc' };
+
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={testProps} />,
+      mountpoint
+    );
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={testProps} />,
+      mountpoint
+    );
+    expect(renderSpy).toHaveBeenCalledTimes(1);
+  });
+
+  it('should not render again if props do not change shallowly', () => {
+    const renderSpy = jest.fn();
+    const testProps = { a: 'abc' };
+
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={testProps} />,
+      mountpoint
+    );
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={{ ...testProps }} />,
+      mountpoint
+    );
+    expect(renderSpy).toHaveBeenCalledTimes(1);
+  });
+
+  it('should not render again for unchanged callback functions', () => {
+    const renderSpy = jest.fn();
+    const testCallback = () => {};
+    const testState = { a: 'abc' };
+
+    render(
+      <NativeRenderer
+        render={renderSpy}
+        nativeProps={{ state: testState, setState: testCallback }}
+      />,
+      mountpoint
+    );
+    render(
+      <NativeRenderer
+        render={renderSpy}
+        nativeProps={{ state: testState, setState: testCallback }}
+      />,
+      mountpoint
+    );
+    expect(renderSpy).toHaveBeenCalledTimes(1);
+  });
+
+  it('should render again once if props change', () => {
+    const renderSpy = jest.fn();
+    const testProps = { a: 'abc' };
+
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={testProps} />,
+      mountpoint
+    );
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={{ a: 'def' }} />,
+      mountpoint
+    );
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={{ a: 'def' }} />,
+      mountpoint
+    );
+    expect(renderSpy).toHaveBeenCalledTimes(2);
+    const containerElement = mountpoint.firstElementChild;
+    expect(renderSpy).lastCalledWith(containerElement, { a: 'def' });
+  });
+
+  it('should render again once if props is just a string', () => {
+    const renderSpy = jest.fn();
+    const testProps = 'abc';
+
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={testProps} />,
+      mountpoint
+    );
+    renderAndTriggerHooks(<NativeRenderer render={renderSpy} nativeProps="def" />, mountpoint);
+    renderAndTriggerHooks(<NativeRenderer render={renderSpy} nativeProps="def" />, mountpoint);
+    expect(renderSpy).toHaveBeenCalledTimes(2);
+    const containerElement = mountpoint.firstElementChild;
+    expect(renderSpy).lastCalledWith(containerElement, 'def');
+  });
+
+  it('should render again if props are extended', () => {
+    const renderSpy = jest.fn();
+    const testProps = { a: 'abc' };
+
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={testProps} />,
+      mountpoint
+    );
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={{ a: 'abc', b: 'def' }} />,
+      mountpoint
+    );
+    expect(renderSpy).toHaveBeenCalledTimes(2);
+    const containerElement = mountpoint.firstElementChild;
+    expect(renderSpy).lastCalledWith(containerElement, { a: 'abc', b: 'def' });
+  });
+
+  it('should render again if props are limited', () => {
+    const renderSpy = jest.fn();
+    const testProps = { a: 'abc', b: 'def' };
+
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={testProps} />,
+      mountpoint
+    );
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={{ a: 'abc' }} />,
+      mountpoint
+    );
+    expect(renderSpy).toHaveBeenCalledTimes(2);
+    const containerElement = mountpoint.firstElementChild;
+    expect(renderSpy).lastCalledWith(containerElement, { a: 'abc' });
+  });
+
+  it('should render a div as container', () => {
+    const renderSpy = jest.fn();
+    const testProps = { a: 'abc' };
+
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} nativeProps={testProps} />,
+      mountpoint
+    );
+    const containerElement: Element = mountpoint.firstElementChild!;
+    expect(containerElement.nodeName).toBe('DIV');
+  });
+
+  it('should render a specified element as container', () => {
+    const renderSpy = jest.fn();
+    const testProps = { a: 'abc' };
+
+    renderAndTriggerHooks(
+      <NativeRenderer render={renderSpy} tag="span" nativeProps={testProps} />,
+      mountpoint
+    );
+    const containerElement: Element = mountpoint.firstElementChild!;
+    expect(containerElement.nodeName).toBe('SPAN');
+  });
+});

x-pack/plugins/lens/public/native_renderer/native_renderer.tsx

@@ -0,0 +1,80 @@
+/*
+ * 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, { useEffect, useRef } from 'react';
+
+export interface NativeRendererProps<T> {
+  render: (domElement: Element, props: T) => void;
+  nativeProps: T;
+  tag?: string;
+  children?: never;
+}
+
+function is(x: unknown, y: unknown) {
+  return (x === y && (x !== 0 || 1 / (x as number) === 1 / (y as number))) || (x !== x && y !== y);
+}
+
+function isShallowDifferent<T>(objA: T, objB: T): boolean {
+  if (is(objA, objB)) {
+    return false;
+  }
+
+  if (typeof objA !== 'object' || objA === null || typeof objB !== 'object' || objB === null) {
+    return true;
+  }
+
+  const keysA = Object.keys(objA) as Array<keyof T>;
+  const keysB = Object.keys(objB) as Array<keyof T>;
+
+  if (keysA.length !== keysB.length) {
+    return true;
+  }
+
+  for (let i = 0; i < keysA.length; i++) {
+    if (!window.hasOwnProperty.call(objB, keysA[i]) || !is(objA[keysA[i]], objB[keysA[i]])) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+/**
+ * A component which takes care of providing a mountpoint for a generic render
+ * function which takes an html element and an optional props object.
+ * It also takes care of calling render again if the props object changes.
+ * By default the mountpoint element will be a div, this can be changed with the
+ * `tag` prop.
+ *
+ * @param props
+ */
+export function NativeRenderer<T>({ render, nativeProps, tag }: NativeRendererProps<T>) {
+  const elementRef = useRef<Element | null>(null);
+  const propsRef = useRef<T | null>(null);
+
+  function renderAndUpdate(element: Element) {
+    elementRef.current = element;
+    propsRef.current = nativeProps;
+    render(element, nativeProps);
+  }
+
+  useEffect(
+    () => {
+      if (elementRef.current && isShallowDifferent(propsRef.current, nativeProps)) {
+        renderAndUpdate(elementRef.current);
+      }
+    },
+    [nativeProps]
+  );
+
+  return React.createElement(tag || 'div', {
+    ref: element => {
+      if (element && element !== elementRef.current) {
+        renderAndUpdate(element);
+      }
+    },
+  });
+}