feat(window post message communicator): Add uuid to frames

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

src/components/editor-page/render-context/editor-to-renderer-communicator-context-provider.tsx

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
@@ -7,6 +7,7 @@
 import type { PropsWithChildren } from 'react'
 import React, { createContext, useContext, useEffect, useMemo } from 'react'
 import { EditorToRendererCommunicator } from '../../render-page/window-post-message-communicator/editor-to-renderer-communicator'
+import { v4 as uuid } from 'uuid'
 
 const EditorToRendererCommunicatorContext = createContext<EditorToRendererCommunicator | undefined>(undefined)
 
@@ -27,8 +28,8 @@ export const useEditorToRendererCommunicator: () => EditorToRendererCommunicator
 /**
  * Provides a {@link EditorToRendererCommunicator editor to renderer communicator} for the child components via Context.
  */
-export const EditorToRendererCommunicatorContextProvider: React.FC<PropsWithChildren<unknown>> = ({ children }) => {
-  const communicator = useMemo<EditorToRendererCommunicator>(() => new EditorToRendererCommunicator(), [])
+export const EditorToRendererCommunicatorContextProvider: React.FC<PropsWithChildren> = ({ children }) => {
+  const communicator = useMemo<EditorToRendererCommunicator>(() => new EditorToRendererCommunicator(uuid()), [])
 
   useEffect(() => {
     const currentCommunicator = communicator

src/components/editor-page/render-context/renderer-to-editor-communicator-context-provider.tsx

@@ -9,6 +9,7 @@ import React, { createContext, useContext, useEffect, useMemo } from 'react'
 import { RendererToEditorCommunicator } from '../../render-page/window-post-message-communicator/renderer-to-editor-communicator'
 import { CommunicationMessageType } from '../../render-page/window-post-message-communicator/rendering-message'
 import { ORIGIN, useBaseUrl } from '../../../hooks/common/use-base-url'
+import { useSingleStringUrlParameter } from '../../../hooks/common/use-single-string-url-parameter'
 
 const RendererToEditorCommunicatorContext = createContext<RendererToEditorCommunicator | undefined>(undefined)
 
@@ -28,7 +29,14 @@ export const useRendererToEditorCommunicator: () => RendererToEditorCommunicator
 
 export const RendererToEditorCommunicatorContextProvider: React.FC<PropsWithChildren<unknown>> = ({ children }) => {
   const editorOrigin = useBaseUrl(ORIGIN.EDITOR)
-  const communicator = useMemo<RendererToEditorCommunicator>(() => new RendererToEditorCommunicator(), [])
+  const uuid = useSingleStringUrlParameter('uuid', undefined)
+  const communicator = useMemo<RendererToEditorCommunicator>(() => {
+    if (uuid === undefined) {
+      throw new Error('no uuid found in url!')
+    } else {
+      return new RendererToEditorCommunicator(uuid)
+    }
+  }, [uuid])
 
   useEffect(() => {
     const currentCommunicator = communicator

src/components/editor-page/renderer-pane/hooks/use-force-render-page-url-on-iframe-load-callback.ts

@@ -8,6 +8,7 @@ import type { RefObject } from 'react'
 import { useCallback, useEffect, useMemo, useRef } from 'react'
 import { Logger } from '../../../../utils/logger'
 import { ORIGIN, useBaseUrl } from '../../../../hooks/common/use-base-url'
+import { useEditorToRendererCommunicator } from '../../render-context/editor-to-renderer-communicator-context-provider'
 
 const log = new Logger('IframeLoader')
 
@@ -19,14 +20,16 @@ const log = new Logger('IframeLoader')
  */
 export const useForceRenderPageUrlOnIframeLoadCallback = (
   iFrameReference: RefObject<HTMLIFrameElement>,
-  onNavigateAway?: () => void
+  onNavigateAway: () => void
 ): (() => void) => {
+  const iframeCommunicator = useEditorToRendererCommunicator()
   const rendererBaseUrl = useBaseUrl(ORIGIN.RENDERER)
   const forcedUrl = useMemo(() => {
     const renderUrl = new URL(rendererBaseUrl)
     renderUrl.pathname += 'render'
+    renderUrl.searchParams.set('uuid', iframeCommunicator.getUuid())
     return renderUrl.toString()
-  }, [rendererBaseUrl])
+  }, [iframeCommunicator, rendererBaseUrl])
   const redirectionInProgress = useRef<boolean>(false)
 
   const loadCallback = useCallback(() => {

src/components/render-page/window-post-message-communicator/window-post-message-communicator.ts

@@ -17,6 +17,11 @@ export type Handler<MESSAGES, MESSAGE_TYPE extends string> = (
   values: Extract<MESSAGES, MessagePayload<MESSAGE_TYPE>>
 ) => void
 
+export interface MessagePayloadWithUuid<MESSAGE_TYPE extends string> {
+  uuid: string
+  payload: MessagePayload<MESSAGE_TYPE>
+}
+
 export interface MessagePayload<MESSAGE_TYPE extends string> {
   type: MESSAGE_TYPE
 }
@@ -36,12 +41,16 @@ export abstract class WindowPostMessageCommunicator<
   private readonly log: Logger
   private readonly boundListener: (event: MessageEvent) => void
 
-  public constructor() {
+  public constructor(private uuid: string) {
     this.boundListener = this.handleEvent.bind(this)
     this.communicationEnabled = false
     this.log = this.createLogger()
   }
 
+  public getUuid(): string {
+    return this.uuid
+  }
+
   protected abstract createLogger(): Logger
 
   /**
@@ -104,7 +113,13 @@ export abstract class WindowPostMessageCommunicator<
       )
     }
     this.log.debug('Sent event', message)
-    this.messageTarget.postMessage(message, this.targetOrigin)
+    this.messageTarget.postMessage(
+      {
+        uuid: this.uuid,
+        payload: message
+      } as MessagePayloadWithUuid<SEND_TYPE>,
+      this.targetOrigin
+    )
   }
 
   /**
@@ -135,19 +150,13 @@ export abstract class WindowPostMessageCommunicator<
    * @param event The received event
    * @return {@link true} if the event was processed.
    */
-  protected handleEvent(event: MessageEvent<MessagePayload<RECEIVE_TYPE>>): void {
-    Optional.ofNullable(event.data).ifPresent((payload) => {
-      event.stopPropagation()
-      event.preventDefault()
-      this.processPayload(payload)
-    })
-  }
-
-  /**
-   * Processes a {@link MessagePayload message payload} using the correct {@link Handler handler}.
-   * @param payload The payload that should be processed
-   */
-  private processPayload(payload: MessagePayload<string>): void {
-    this.emitter.emit(payload.type, payload)
+  protected handleEvent(event: MessageEvent<MessagePayloadWithUuid<RECEIVE_TYPE>>): void {
+    Optional.ofNullable(event.data)
+      .filter((value) => value.uuid === this.uuid)
+      .ifPresent((payload) => {
+        event.stopPropagation()
+        event.preventDefault()
+        this.emitter.emit(payload.payload.type, payload.payload)
+      })
   }
 }