chore: mobile web bridge concept (#1228)

packages/mobile/MobileWebAppContainer.tsx

@@ -1,26 +1,131 @@
-import React from 'react'
+import { MobileDeviceInterface } from '@Lib/Interface'
+import React, { useMemo, useRef } from 'react'
 import { Platform } from 'react-native'
-import { WebView } from 'react-native-webview'
+import { WebView, WebViewMessageEvent } from 'react-native-webview'
 
 export const MobileWebAppContainer = () => {
-  const sourceUri = (Platform.OS === 'android' ? 'file:///android_asset/' : '') + 'Web.bundle/loader.html'
+  const sourceUri = (Platform.OS === 'android' ? 'file:///android_asset/' : '') + 'Web.bundle/src/index.html'
-  const params = 'platform=' + Platform.OS
+  const webViewRef = useRef<WebView>(null)
+
+  const device = useMemo(() => new MobileDeviceInterface(), [])
+  const functions = Object.getOwnPropertyNames(Object.getPrototypeOf(device))
+
+  const baselineFunctions: Record<string, any> = {
+    isDeviceDestroyed: `(){
+      return false
+    }`,
+  }
+
+  let stringFunctions = ''
+  for (const [key, value] of Object.entries(baselineFunctions)) {
+    stringFunctions += `${key}${value}`
+  }
+
+  for (const functionName of functions) {
+    if (functionName === 'constructor' || baselineFunctions[functionName]) {
+      continue
+    }
+
+    stringFunctions += `
+    ${functionName}(...args) {
+      return this.sendMessage('${functionName}', args);
+    }
+    `
+  }
+
+  const WebProcessDeviceInterface = `
+  class WebProcessDeviceInterface {
+    constructor(messageSender) {
+      this.appVersion = '1.2.3'
+      this.environment = 1
+      this.databases = []
+      this.messageSender = messageSender
+    }
+
+    setApplication() {}
+
+    sendMessage(functionName, args) {
+      return this.messageSender.sendMessage(functionName, args)
+    }
+
+    ${stringFunctions}
+  }
+  `
+
+  const WebProcessMessageSender = `
+  class WebProcessMessageSender {
+    constructor() {
+      this.pendingMessages = []
+      window.addEventListener('message', this.handleMessageFromReactNative.bind(this))
+    }
+
+    handleMessageFromReactNative(event) {
+      const message = event.data
+      try {
+        const parsed = JSON.parse(message)
+        const { messageId, returnValue } = parsed
+        const pendingMessage = this.pendingMessages.find((m) => m.messageId === messageId)
+        pendingMessage.resolve(returnValue)
+        this.pendingMessages.splice(this.pendingMessages.indexOf(pendingMessage), 1)
+      } catch (error) {
+        console.log('Error parsing message from React Native', message, error)
+      }
+    }
+
+    sendMessage(functionName, args) {
+      const messageId = Math.random()
+      window.ReactNativeWebView.postMessage(JSON.stringify({ functionName: functionName, args: args, messageId }))
+      return new Promise((resolve) => {
+        this.pendingMessages.push({
+          messageId,
+          resolve,
+        })
+      })
+    }
+  }
+  `
+
   const injectedJS = `
-    if (!window.location.search) {
+
-      var link = document.getElementById('web-bundle-progress-bar');
+  console.log = (...args) => {
-      link.href = './src/index.html?${params}';
+    window.ReactNativeWebView.postMessage('[web log] ' + args.join(' '));
-      link.click();
+  }
-    }`
+
+  ${WebProcessDeviceInterface}
+  ${WebProcessMessageSender}
+
+  const messageSender = new WebProcessMessageSender();
+  window.reactNativeDevice = new WebProcessDeviceInterface(messageSender);
+
+  true;
+    `
+
+  const onMessage = (event: WebViewMessageEvent) => {
+    const message = event.nativeEvent.data
+    try {
+      const functionData = JSON.parse(message)
+      void onFunctionMessage(functionData.functionName, functionData.messageId, functionData.args)
+    } catch (error) {
+      console.log('onGeneralMessage', JSON.stringify(message))
+    }
+  }
+
+  const onFunctionMessage = async (functionName: string, messageId: string, args: any) => {
+    const returnValue = await (device as any)[functionName](...args)
+    console.log(`Native device function ${functionName} called`)
+    webViewRef.current?.postMessage(JSON.stringify({ messageId, returnValue }))
+  }
 
   /* eslint-disable @typescript-eslint/no-empty-function */
   return (
     <WebView
+      ref={webViewRef}
       source={{ uri: sourceUri }}
       originWhitelist={['*']}
       onLoad={() => {}}
       onError={(err) => console.error('An error has occurred', err)}
       onHttpError={() => console.error('An HTTP error occurred')}
-      onMessage={() => {}}
+      onMessage={onMessage}
       allowFileAccess={true}
       injectedJavaScript={injectedJS}
     />

packages/mobile/WebFrame/DeviceInterface.template.js

@@ -0,0 +1,15 @@
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+class WebProcessDeviceInterface {
+  constructor(messageSender) {
+    this.appVersion = '1.2.3'
+    this.environment = 1
+    this.databases = []
+    this.messageSender = messageSender
+  }
+
+  setApplication() {}
+
+  sendMessage(functionName, args) {
+    return this.messageSender.sendMessage(functionName, args)
+  }
+}

packages/mobile/WebFrame/MessageSender.template.js

@@ -0,0 +1,31 @@
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+class WebProcessMessageSender {
+  constructor() {
+    this.pendingMessages = []
+    window.addEventListener('message', this.handleMessageFromReactNative.bind(this))
+  }
+
+  handleMessageFromReactNative(event) {
+    const message = event.data
+    try {
+      const parsed = JSON.parse(message)
+      const { messageId, returnValue } = parsed
+      const pendingMessage = this.pendingMessages.find((m) => m.messageId === messageId)
+      pendingMessage.resolve(returnValue)
+      this.pendingMessages.splice(this.pendingMessages.indexOf(pendingMessage), 1)
+    } catch (error) {
+      console.log('Error parsing message from React Native', message, error)
+    }
+  }
+
+  sendMessage(functionName, args) {
+    const messageId = Math.random()
+    window.ReactNativeWebView.postMessage(JSON.stringify({ functionName: functionName, args: args, messageId }))
+    return new Promise((resolve) => {
+      this.pendingMessages.push({
+        messageId,
+        resolve,
+      })
+    })
+  }
+}

packages/mobile/src/AppStack.tsx

@@ -1,16 +1,17 @@
 import { AppStateEventType, AppStateType, TabletModeChangeData } from '@Lib/ApplicationState'
 import { useHasEditor, useIsLocked } from '@Lib/SnjsHelperHooks'
 import { ScreenStatus } from '@Lib/StatusManager'
+import { IsDev } from '@Lib/Utils'
 import { CompositeNavigationProp, RouteProp } from '@react-navigation/native'
 import { createStackNavigator, StackNavigationProp } from '@react-navigation/stack'
 import { HeaderTitleView } from '@Root/Components/HeaderTitleView'
 import { IoniconsHeaderButton } from '@Root/Components/IoniconsHeaderButton'
 import { Compose } from '@Root/Screens/Compose/Compose'
-import { Root } from '@Root/Screens/Root'
 import { SCREEN_COMPOSE, SCREEN_NOTES, SCREEN_VIEW_PROTECTED_NOTE } from '@Root/Screens/screens'
 import { MainSideMenu } from '@Root/Screens/SideMenu/MainSideMenu'
 import { NoteSideMenu } from '@Root/Screens/SideMenu/NoteSideMenu'
 import { ViewProtectedNote } from '@Root/Screens/ViewProtectedNote/ViewProtectedNote'
+import { Root } from '@Screens/Root'
 import { UuidString } from '@standardnotes/snjs'
 import { ICON_MENU } from '@Style/Icons'
 import { ThemeService } from '@Style/ThemeService'
@@ -20,10 +21,14 @@ import { Dimensions, Keyboard, ScaledSize } from 'react-native'
 import DrawerLayout, { DrawerState } from 'react-native-gesture-handler/DrawerLayout'
 import { HeaderButtons, Item } from 'react-navigation-header-buttons'
 import { ThemeContext } from 'styled-components'
+import { MobileWebAppContainer } from '../MobileWebAppContainer'
 import { HeaderTitleParams } from './App'
 import { ApplicationContext } from './ApplicationContext'
 import { ModalStackNavigationProp } from './ModalStack'
 
+const IS_DEBUGGING_WEB_APP = false
+const DEFAULT_TO_WEB_APP = IsDev && IS_DEBUGGING_WEB_APP
+
 export type AppStackNavigatorParamList = {
   [SCREEN_NOTES]: HeaderTitleParams
   [SCREEN_COMPOSE]: HeaderTitleParams & {
@@ -196,7 +201,7 @@ export const AppStackComponent = (props: ModalStackNavigationProp<'AppStack'>) =
                   </HeaderButtons>
                 ),
             })}
-            component={Root}
+            component={DEFAULT_TO_WEB_APP ? MobileWebAppContainer : Root}
           />
           <AppStack.Screen
             name={SCREEN_COMPOSE}

packages/web/src/javascripts/App.tsx

@@ -15,6 +15,7 @@ declare global {
     electronAppVersion?: string
     webClient?: DesktopManagerInterface
     electronRemoteBridge?: unknown
+    reactNativeDevice?: WebDevice
 
     application?: WebApplication
     mainApplicationGroup?: ApplicationGroup
@@ -88,12 +89,14 @@ const startApplication: StartApplication = async function startApplication(
 }
 
 if (IsWebPlatform) {
-  startApplication(
+  const ReactNativeWebViewInitializationTimeout = 0
-    window.defaultSyncServer,
+
-    new WebDevice(WebAppVersion),
+  setTimeout(() => {
-    window.enabledUnfinishedFeatures,
+    const device = window.reactNativeDevice || new WebDevice(WebAppVersion)
-    window.websocketUrl,
+    startApplication(window.defaultSyncServer, device, window.enabledUnfinishedFeatures, window.websocketUrl).catch(
-  ).catch(console.error)
+      console.error,
+    )
+  }, ReactNativeWebViewInitializationTimeout)
 } else {
   window.startApplication = startApplication
 }