refactor(renderer): convert html/markdown-to-react converters from hooks to components

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

frontend/src/components/common/html-to-react/__snapshots__/html-to-react.test.tsx.snap

@@ -0,0 +1,30 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`HTML to React renders basic html correctly 1`] = `
+<div>
+  <p>
+    This is a test 
+    <b>
+      sentence
+    </b>
+  </p>
+</div>
+`;
+
+exports[`HTML to React will forward the DomPurify settings 1`] = `
+<div>
+  <test-tag>
+    Test!
+  </test-tag>
+</div>
+`;
+
+exports[`HTML to React will forward the parser options 1`] = `
+<div>
+  <p>
+    Hijacked!
+  </p>
+</div>
+`;
+
+exports[`HTML to React won't render script tags 1`] = `<div />`;

frontend/src/components/common/html-to-react/html-to-react.test.tsx

@@ -0,0 +1,50 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { HtmlToReact } from './html-to-react'
+import { render } from '@testing-library/react'
+
+describe('HTML to React', () => {
+  it('renders basic html correctly', () => {
+    const view = render(<HtmlToReact htmlCode={'<p>This is a test <b>sentence</b></p>'} />)
+    expect(view.container).toMatchSnapshot()
+  })
+
+  it("won't render script tags", () => {
+    const view = render(<HtmlToReact htmlCode={'<script type="application/javascript">alert("XSS!")</script>'} />)
+    expect(view.container).toMatchSnapshot()
+  })
+
+  it('will forward the DomPurify settings', () => {
+    const view = render(
+      <HtmlToReact domPurifyConfig={{ ADD_TAGS: ['test-tag'] }} htmlCode={'<test-tag>Test!</test-tag>'} />
+    )
+    expect(view.container).toMatchSnapshot()
+  })
+
+  it('will forward the parser options', () => {
+    let transformerVisited = false
+    let preprocessNodesVisited = false
+
+    const view = render(
+      <HtmlToReact
+        htmlCode={'<p>This is a sentence</p>'}
+        parserOptions={{
+          transform: () => {
+            transformerVisited = true
+            return <p>Hijacked!</p>
+          },
+          preprocessNodes: (document) => {
+            preprocessNodesVisited = true
+            return document
+          }
+        }}
+      />
+    )
+    expect(view.container).toMatchSnapshot()
+    expect(preprocessNodesVisited).toBeTruthy()
+    expect(transformerVisited).toBeTruthy()
+  })
+})

frontend/src/components/common/html-to-react/html-to-react.tsx

@@ -0,0 +1,32 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import type { ParserOptions } from '@hedgedoc/html-to-react'
+import convertHtmlToReact from '@hedgedoc/html-to-react'
+import type DOMPurify from 'dompurify'
+import { sanitize } from 'dompurify'
+import React, { Fragment, useMemo } from 'react'
+
+export interface HtmlToReactProps {
+  htmlCode: string
+  domPurifyConfig?: DOMPurify.Config
+  parserOptions?: ParserOptions
+}
+
+/**
+ * Renders
+ * @param htmlCode
+ * @param domPurifyConfig
+ * @param parserOptions
+ * @constructor
+ */
+export const HtmlToReact: React.FC<HtmlToReactProps> = ({ htmlCode, domPurifyConfig, parserOptions }) => {
+  const elements = useMemo(() => {
+    const sanitizedHtmlCode = sanitize(htmlCode, { ...domPurifyConfig, RETURN_DOM_FRAGMENT: false, RETURN_DOM: false })
+    return convertHtmlToReact(sanitizedHtmlCode, parserOptions)
+  }, [domPurifyConfig, htmlCode, parserOptions])
+
+  return <Fragment>{elements}</Fragment>
+}

frontend/src/components/markdown-renderer/document-markdown-renderer.tsx

@@ -7,11 +7,12 @@ import { cypressId } from '../../utils/cypress-attribute'
 import type { CommonMarkdownRendererProps } from './common-markdown-renderer-props'
 import { HeadlineAnchorsMarkdownExtension } from './extensions/headline-anchors-markdown-extension'
 import type { LineMarkers } from './extensions/linemarker/add-line-marker-markdown-it-plugin'
+import { LinemarkerMarkdownExtension } from './extensions/linemarker/linemarker-markdown-extension'
 import type { LineMarkerPosition } from './extensions/linemarker/types'
-import { useConvertMarkdownToReactDom } from './hooks/use-convert-markdown-to-react-dom'
+import { useCalculateLineMarkerPosition } from './hooks/use-calculate-line-marker-positions'
 import { useExtractFirstHeadline } from './hooks/use-extract-first-headline'
 import { useMarkdownExtensions } from './hooks/use-markdown-extensions'
-import { useCalculateLineMarkerPosition } from './utils/calculate-line-marker-positions'
+import { MarkdownToReact } from './markdown-to-react/markdown-to-react'
 import React, { useEffect, useMemo, useRef } from 'react'
 import { useTranslation } from 'react-i18next'
 
@@ -27,9 +28,7 @@ export interface DocumentMarkdownRendererProps extends CommonMarkdownRendererPro
  * @param onFirstHeadingChange The callback to call if the first heading changes.
  * @param onLineMarkerPositionChanged The callback to call with changed {@link LineMarkers}
  * @param onTaskCheckedChange The callback to call if a task is checked or unchecked.
- * @param onTocChange The callback to call if the toc changes.
  * @param baseUrl The base url of the renderer
- * @param onImageClick The callback to call if a image is clicked
  * @param outerContainerRef A reference for the outer container
  * @param newlinesAreBreaks If newlines are rendered as breaks or not
  */
@@ -47,19 +46,17 @@ export const DocumentMarkdownRenderer: React.FC<DocumentMarkdownRendererProps> =
 
   const extensions = useMarkdownExtensions(
     baseUrl,
-    currentLineMarkers,
-    useMemo(() => [new HeadlineAnchorsMarkdownExtension()], [])
+    useMemo(
+      () => [
+        new HeadlineAnchorsMarkdownExtension(),
+        new LinemarkerMarkdownExtension((values) => (currentLineMarkers.current = values))
+      ],
+      []
+    )
   )
-
-  const markdownReactDom = useConvertMarkdownToReactDom(markdownContentLines, extensions, newlinesAreBreaks, true)
 
   useTranslation()
-  useCalculateLineMarkerPosition(
-    markdownBodyRef,
-    currentLineMarkers.current,
-    onLineMarkerPositionChanged,
-    markdownBodyRef.current?.offsetTop ?? 0
-  )
+  useCalculateLineMarkerPosition(markdownBodyRef, currentLineMarkers.current, onLineMarkerPositionChanged)
   const extractFirstHeadline = useExtractFirstHeadline(markdownBodyRef, onFirstHeadingChange)
   useEffect(() => {
     extractFirstHeadline()
@@ -72,7 +69,12 @@ export const DocumentMarkdownRenderer: React.FC<DocumentMarkdownRendererProps> =
         ref={markdownBodyRef}
         data-word-count-target={true}
         className={`${className ?? ''} markdown-body w-100 d-flex flex-column align-items-center`}>
-        {markdownReactDom}
+        <MarkdownToReact
+          markdownContentLines={markdownContentLines}
+          markdownRenderExtensions={extensions}
+          newlinesAreBreaks={newlinesAreBreaks}
+          allowHtml={true}
+        />
       </div>
     </div>
   )

frontend/src/components/markdown-renderer/extensions/image-placeholder/image-placeholder-markdown-extension.ts

@@ -15,10 +15,6 @@ import type MarkdownIt from 'markdown-it/lib'
 export class ImagePlaceholderMarkdownExtension extends MarkdownRendererExtension {
   public static readonly PLACEHOLDER_URL = 'https://'
 
-  constructor() {
-    super()
-  }
-
   configureMarkdownIt(markdownIt: MarkdownIt): void {
     addLineToPlaceholderImageTags(markdownIt)
   }

frontend/src/components/markdown-renderer/extensions/linemarker/types.d.ts

@@ -9,6 +9,9 @@ export interface LineWithId {
   id: number
 }
 
+/**
+ * Defines the line number of a line marker and its absolute scroll position on the page.
+ */
 export interface LineMarkerPosition {
   line: number
   position: number

frontend/src/components/markdown-renderer/extensions/sanitizer/dom-purifier-node-preprocessor.ts

@@ -1,28 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-import { NodeProcessor } from '../../node-preprocessors/node-processor'
-import render from 'dom-serializer'
-import type { Document } from 'domhandler'
-import DOMPurify from 'dompurify'
-import { parseDocument } from 'htmlparser2'
-
-/**
- * Sanitizes the given {@link Document document}.
- *
- * @see https://cure53.de/purify
- */
-export class SanitizerNodePreprocessor extends NodeProcessor {
-  constructor(private tagNameWhiteList: string[]) {
-    super()
-  }
-
-  process(nodes: Document): Document {
-    const sanitizedHtml = DOMPurify.sanitize(render(nodes), {
-      ADD_TAGS: this.tagNameWhiteList
-    })
-    return parseDocument(sanitizedHtml)
-  }
-}

frontend/src/components/markdown-renderer/extensions/sanitizer/sanitizer-markdown-extension.ts

@@ -1,21 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-import type { NodeProcessor } from '../../node-preprocessors/node-processor'
-import { MarkdownRendererExtension } from '../base/markdown-renderer-extension'
-import { SanitizerNodePreprocessor } from './dom-purifier-node-preprocessor'
-
-/**
- * Adds support for html sanitizing using dompurify to the markdown rendering.
- */
-export class SanitizerMarkdownExtension extends MarkdownRendererExtension {
-  constructor(private tagNameWhiteList: string[]) {
-    super()
-  }
-
-  public buildNodeProcessors(): NodeProcessor[] {
-    return [new SanitizerNodePreprocessor(this.tagNameWhiteList)]
-  }
-}

frontend/src/components/markdown-renderer/extensions/table-of-contents-markdown-extension.ts

@@ -18,6 +18,8 @@ export class TableOfContentsMarkdownExtension extends MarkdownRendererExtension
   private lastAst: TocAst | undefined = undefined
 
   public configureMarkdownIt(markdownIt: MarkdownIt): void {
+    const eventEmitter = this.eventEmitter
+    if (eventEmitter !== undefined) {
       toc(markdownIt, {
         listType: 'ul',
         level: [1, 2, 3],
@@ -26,9 +28,10 @@ export class TableOfContentsMarkdownExtension extends MarkdownRendererExtension
             return
           }
           this.lastAst = ast
-        this.eventEmitter?.emit(TableOfContentsMarkdownExtension.EVENT_NAME, ast)
+          eventEmitter.emit(TableOfContentsMarkdownExtension.EVENT_NAME, ast)
         },
         slugify: tocSlugify
       })
     }
+  }
 }

frontend/src/components/markdown-renderer/hooks/use-calculate-line-marker-positions.ts

@@ -52,13 +52,11 @@ const calculateLineMarkerPositions = (
  * @param documentElement A reference to the rendered document.
  * @param lineMarkers A list of {@link LineMarkers}
  * @param onLineMarkerPositionChanged The callback to call if the {@link LineMarkerPosition line marker positions} change e.g. by rendering or resizing.
- * @param offset The optional offset
  */
 export const useCalculateLineMarkerPosition = (
   documentElement: RefObject<HTMLDivElement>,
-  lineMarkers?: LineMarkers[],
-  onLineMarkerPositionChanged?: (lineMarkerPosition: LineMarkerPosition[]) => void,
-  offset?: number
+  lineMarkers: LineMarkers[] | undefined,
+  onLineMarkerPositionChanged?: (lineMarkerPosition: LineMarkerPosition[]) => void
 ): void => {
   const lastLineMarkerPositions = useRef<LineMarkerPosition[]>()
 
@@ -67,13 +65,17 @@ export const useCalculateLineMarkerPosition = (
       return
     }
 
-    const newLines = calculateLineMarkerPositions(documentElement.current, lineMarkers, offset)
+    const newLines = calculateLineMarkerPositions(
+      documentElement.current,
+      lineMarkers,
+      documentElement.current.offsetTop ?? 0
+    )
 
     if (!equal(newLines, lastLineMarkerPositions)) {
       lastLineMarkerPositions.current = newLines
       onLineMarkerPositionChanged(newLines)
     }
-  }, [documentElement, lineMarkers, offset, onLineMarkerPositionChanged])
+  }, [documentElement, lineMarkers, onLineMarkerPositionChanged])
 
   useEffect(() => {
     calculateNewLineMarkerPositions()

frontend/src/components/markdown-renderer/hooks/use-convert-markdown-to-react-dom.tsx

@@ -1,62 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-import type { MarkdownRendererExtension } from '../extensions/base/markdown-renderer-extension'
-import { SanitizerMarkdownExtension } from '../extensions/sanitizer/sanitizer-markdown-extension'
-import type { ValidReactDomElement } from '../replace-components/component-replacer'
-import { LineIdMapper } from '../utils/line-id-mapper'
-import { NodeToReactTransformer } from '../utils/node-to-react-transformer'
-import { useCombinedNodePreprocessor } from './use-combined-node-preprocessor'
-import { useConfiguredMarkdownIt } from './use-configured-markdown-it'
-import convertHtmlToReact from '@hedgedoc/html-to-react'
-import React, { Fragment, useMemo } from 'react'
-
-/**
- * Renders Markdown-Code into react elements.
- *
- * @param markdownContentLines The Markdown code lines that should be rendered
- * @param additionalMarkdownExtensions A list of {@link MarkdownRendererExtension markdown extensions} that should be used
- * @param newlinesAreBreaks Defines if the alternative break mode of markdown it should be used
- * @param allowHtml Defines if html is allowed in markdown
- * @return The React DOM that represents the rendered Markdown code
- */
-export const useConvertMarkdownToReactDom = (
-  markdownContentLines: string[],
-  additionalMarkdownExtensions: MarkdownRendererExtension[],
-  newlinesAreBreaks = true,
-  allowHtml = true
-): ValidReactDomElement => {
-  const lineNumberMapper = useMemo(() => new LineIdMapper(), [])
-  const htmlToReactTransformer = useMemo(() => new NodeToReactTransformer(), [])
-  const markdownExtensions = useMemo(() => {
-    const tagWhiteLists = additionalMarkdownExtensions.flatMap((extension) => extension.buildTagNameAllowList())
-    return [...additionalMarkdownExtensions, new SanitizerMarkdownExtension(tagWhiteLists)]
-  }, [additionalMarkdownExtensions])
-
-  useMemo(() => {
-    htmlToReactTransformer.setReplacers(markdownExtensions.flatMap((extension) => extension.buildReplacers()))
-  }, [htmlToReactTransformer, markdownExtensions])
-
-  useMemo(() => {
-    htmlToReactTransformer.setLineIds(lineNumberMapper.updateLineMapping(markdownContentLines))
-  }, [htmlToReactTransformer, lineNumberMapper, markdownContentLines])
-
-  const nodePreProcessor = useCombinedNodePreprocessor(markdownExtensions)
-  const markdownIt = useConfiguredMarkdownIt(markdownExtensions, allowHtml, newlinesAreBreaks)
-
-  return useMemo(() => {
-    const html = markdownIt.render(markdownContentLines.join('\n'))
-    htmlToReactTransformer.resetReplacers()
-
-    return (
-      <Fragment key={'root'}>
-        {convertHtmlToReact(html, {
-          transform: (node, index) => htmlToReactTransformer.translateNodeToReactElement(node, index),
-          preprocessNodes: (document) => nodePreProcessor(document)
-        })}
-      </Fragment>
-    )
-  }, [htmlToReactTransformer, markdownContentLines, markdownIt, nodePreProcessor])
-}

frontend/src/components/markdown-renderer/hooks/use-markdown-extensions.ts

@@ -12,43 +12,30 @@ import { GenericSyntaxMarkdownExtension } from '../extensions/generic-syntax-mar
 import { IframeCapsuleMarkdownExtension } from '../extensions/iframe-capsule/iframe-capsule-markdown-extension'
 import { ImagePlaceholderMarkdownExtension } from '../extensions/image-placeholder/image-placeholder-markdown-extension'
 import { ProxyImageMarkdownExtension } from '../extensions/image/proxy-image-markdown-extension'
-import type { LineMarkers } from '../extensions/linemarker/add-line-marker-markdown-it-plugin'
-import { LinemarkerMarkdownExtension } from '../extensions/linemarker/linemarker-markdown-extension'
 import { LinkAdjustmentMarkdownExtension } from '../extensions/link-replacer/link-adjustment-markdown-extension'
 import { LinkifyFixMarkdownExtension } from '../extensions/linkify-fix/linkify-fix-markdown-extension'
 import { TableOfContentsMarkdownExtension } from '../extensions/table-of-contents-markdown-extension'
 import { UploadIndicatingImageFrameMarkdownExtension } from '../extensions/upload-indicating-image-frame/upload-indicating-image-frame-markdown-extension'
 import { useExtensionEventEmitter } from './use-extension-event-emitter'
-import type { MutableRefObject } from 'react'
 import { useMemo } from 'react'
 
-const optionalMarkdownRendererExtensions = optionalAppExtensions.flatMap((value) =>
-  value.buildMarkdownRendererExtensions()
-)
-
 /**
  * Provides a list of {@link MarkdownRendererExtension markdown extensions} that is a combination of the common extensions and the given additional.
  *
  * @param baseUrl The base url for the {@link LinkAdjustmentMarkdownExtension}
- * @param currentLineMarkers A {@link MutableRefObject reference} to {@link LineMarkers} for the {@link LinemarkerMarkdownExtension}
  * @param additionalExtensions The additional extensions that should be included in the list
  * @return The created list of markdown extensions
  */
 export const useMarkdownExtensions = (
   baseUrl: string,
-  currentLineMarkers: MutableRefObject<LineMarkers[] | undefined> | undefined,
   additionalExtensions: MarkdownRendererExtension[]
 ): MarkdownRendererExtension[] => {
   const extensionEventEmitter = useExtensionEventEmitter()
-  //replace with global list
   return useMemo(() => {
     return [
-      ...optionalMarkdownRendererExtensions,
+      ...optionalAppExtensions.flatMap((extension) => extension.buildMarkdownRendererExtensions(extensionEventEmitter)),
       ...additionalExtensions,
-      new TableOfContentsMarkdownExtension(extensionEventEmitter),
-      new LinemarkerMarkdownExtension(
-        currentLineMarkers ? (lineMarkers) => (currentLineMarkers.current = lineMarkers) : undefined
-      ),
+      new TableOfContentsMarkdownExtension(),
       new IframeCapsuleMarkdownExtension(),
       new ImagePlaceholderMarkdownExtension(),
       new UploadIndicatingImageFrameMarkdownExtension(),
@@ -60,5 +47,5 @@ export const useMarkdownExtensions = (
       new DebuggerMarkdownExtension(),
       new ProxyImageMarkdownExtension()
     ]
-  }, [additionalExtensions, baseUrl, currentLineMarkers, extensionEventEmitter])
+  }, [additionalExtensions, baseUrl, extensionEventEmitter])
 }

frontend/src/components/markdown-renderer/markdown-to-react/__snapshots__/markdown-to-react.test.tsx.snap

@@ -0,0 +1,92 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`markdown to react can render html if allowed 1`] = `
+<div>
+  <p>
+    <span>
+      test
+    </span>
+  </p>
+  
+
+</div>
+`;
+
+exports[`markdown to react can render markdown with newlines as line breaks 1`] = `
+<div>
+  <h1>
+    This is a headline
+  </h1>
+  
+
+  <p>
+    This is content
+    <br />
+    
+This Too
+  </p>
+  
+
+</div>
+`;
+
+exports[`markdown to react will use markdown render extensions 1`] = `
+<div>
+  <p>
+    &lt;span&gt;test&lt;/span&gt;
+  </p>
+  
+
+  <span>
+    configure
+  </span>
+  <span>
+    post
+  </span>
+  <span>
+    NodeProcessor! 
+  </span>
+  <span
+    data-children="true"
+  >
+     
+    node processor children
+     
+  </span>
+  <span
+    data-native="true"
+  >
+     
+    <nodeprocessor>
+      node processor children
+    </nodeprocessor>
+     
+  </span>
+</div>
+`;
+
+exports[`markdown to react won't render html if forbidden 1`] = `
+<div>
+  <p>
+    &lt;span&gt;test&lt;/span&gt;
+  </p>
+  
+
+</div>
+`;
+
+exports[`markdown to react won't render markdown with newlines as line breaks if forbidden 1`] = `
+<div>
+  <h1>
+    This is a headline
+  </h1>
+  
+
+  <p>
+    This is content
+This Too
+  </p>
+  
+
+</div>
+`;

frontend/src/components/markdown-renderer/markdown-to-react/hooks/use-combined-node-preprocessor.ts

@@ -3,7 +3,7 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import type { MarkdownRendererExtension } from '../extensions/base/markdown-renderer-extension'
+import type { MarkdownRendererExtension } from '../../extensions/base/markdown-renderer-extension'
 import type { Document } from 'domhandler'
 import { useMemo } from 'react'
 

frontend/src/components/markdown-renderer/markdown-to-react/hooks/use-configured-markdown-it.ts

@@ -3,7 +3,7 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import type { MarkdownRendererExtension } from '../extensions/base/markdown-renderer-extension'
+import type { MarkdownRendererExtension } from '../../extensions/base/markdown-renderer-extension'
 import MarkdownIt from 'markdown-it/lib'
 import { useMemo } from 'react'
 

frontend/src/components/markdown-renderer/markdown-to-react/markdown-to-react.test.tsx

@@ -0,0 +1,70 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { MarkdownToReact } from './markdown-to-react'
+import { TestMarkdownRendererExtension } from './test-utils/test-markdown-renderer-extension'
+import { render } from '@testing-library/react'
+import type { EventMap } from 'eventemitter2'
+import { EventEmitter2 } from 'eventemitter2'
+
+describe('markdown to react', () => {
+  it('can render markdown with newlines as line breaks', () => {
+    const view = render(
+      <MarkdownToReact
+        markdownContentLines={['# This is a headline', 'This is content', 'This Too']}
+        allowHtml={false}
+        newlinesAreBreaks={true}
+        markdownRenderExtensions={[]}></MarkdownToReact>
+    )
+    expect(view.container).toMatchSnapshot()
+  })
+
+  it("won't render markdown with newlines as line breaks if forbidden", () => {
+    const view = render(
+      <MarkdownToReact
+        markdownContentLines={['# This is a headline', 'This is content', 'This Too']}
+        allowHtml={false}
+        newlinesAreBreaks={false}
+        markdownRenderExtensions={[]}></MarkdownToReact>
+    )
+    expect(view.container).toMatchSnapshot()
+  })
+
+  it('can render html if allowed', () => {
+    const view = render(
+      <MarkdownToReact
+        markdownContentLines={['<span>test</span>']}
+        markdownRenderExtensions={[]}
+        newlinesAreBreaks={true}
+        allowHtml={true}
+      />
+    )
+    expect(view.container).toMatchSnapshot()
+  })
+
+  it("won't render html if forbidden", () => {
+    const view = render(
+      <MarkdownToReact
+        markdownContentLines={['<span>test</span>']}
+        markdownRenderExtensions={[]}
+        newlinesAreBreaks={true}
+        allowHtml={false}
+      />
+    )
+    expect(view.container).toMatchSnapshot()
+  })
+
+  it('will use markdown render extensions', () => {
+    const view = render(
+      <MarkdownToReact
+        markdownContentLines={['<span>test</span>']}
+        markdownRenderExtensions={[new TestMarkdownRendererExtension(new EventEmitter2<EventMap>())]}
+        newlinesAreBreaks={true}
+        allowHtml={false}
+      />
+    )
+    expect(view.container).toMatchSnapshot()
+  })
+})

frontend/src/components/markdown-renderer/markdown-to-react/markdown-to-react.tsx

@@ -0,0 +1,71 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { HtmlToReact } from '../../common/html-to-react/html-to-react'
+import type { MarkdownRendererExtension } from '../extensions/base/markdown-renderer-extension'
+import { useCombinedNodePreprocessor } from './hooks/use-combined-node-preprocessor'
+import { useConfiguredMarkdownIt } from './hooks/use-configured-markdown-it'
+import { LineContentToLineIdMapper } from './utils/line-content-to-line-id-mapper'
+import { NodeToReactTransformer } from './utils/node-to-react-transformer'
+import type { ParserOptions } from '@hedgedoc/html-to-react'
+import type DOMPurify from 'dompurify'
+import React, { useMemo } from 'react'
+
+export interface MarkdownToReactProps {
+  markdownContentLines: string[]
+  markdownRenderExtensions: MarkdownRendererExtension[]
+  newlinesAreBreaks?: boolean
+  allowHtml: boolean
+}
+
+/**
+ * Renders Markdown code.
+ *
+ * @param markdownContentLines The Markdown code lines that should be rendered
+ * @param additionalMarkdownExtensions A list of {@link MarkdownRendererExtension markdown extensions} that should be used
+ * @param newlinesAreBreaks Defines if the alternative break mode of markdown it should be used
+ * @param allowHtml Defines if html is allowed in markdown
+ */
+export const MarkdownToReact: React.FC<MarkdownToReactProps> = ({
+  markdownContentLines,
+  markdownRenderExtensions,
+  newlinesAreBreaks,
+  allowHtml
+}) => {
+  const lineNumberMapper = useMemo(() => new LineContentToLineIdMapper(), [])
+  const nodeToReactTransformer = useMemo(() => new NodeToReactTransformer(), [])
+
+  useMemo(() => {
+    nodeToReactTransformer.setReplacers(markdownRenderExtensions.flatMap((extension) => extension.buildReplacers()))
+  }, [nodeToReactTransformer, markdownRenderExtensions])
+
+  useMemo(() => {
+    nodeToReactTransformer.setLineIds(lineNumberMapper.updateLineMapping(markdownContentLines))
+  }, [nodeToReactTransformer, lineNumberMapper, markdownContentLines])
+
+  const nodePreProcessor = useCombinedNodePreprocessor(markdownRenderExtensions)
+  const markdownIt = useConfiguredMarkdownIt(markdownRenderExtensions, allowHtml, newlinesAreBreaks ?? true)
+
+  const parserOptions: ParserOptions = useMemo(
+    () => ({
+      transform: (node, index) => nodeToReactTransformer.translateNodeToReactElement(node, index),
+      preprocessNodes: (document) => {
+        nodeToReactTransformer.resetReplacers()
+        return nodePreProcessor(document)
+      }
+    }),
+    [nodeToReactTransformer, nodePreProcessor]
+  )
+
+  const html = useMemo(() => markdownIt.render(markdownContentLines.join('\n')), [markdownContentLines, markdownIt])
+  const domPurifyConfig: DOMPurify.Config = useMemo(
+    () => ({
+      ADD_TAGS: markdownRenderExtensions.flatMap((extension) => extension.buildTagNameAllowList())
+    }),
+    [markdownRenderExtensions]
+  )
+
+  return <HtmlToReact htmlCode={html} parserOptions={parserOptions} domPurifyConfig={domPurifyConfig} />
+}

frontend/src/components/markdown-renderer/markdown-to-react/test-utils/test-markdown-renderer-extension.ts

@@ -0,0 +1,40 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { MarkdownRendererExtension } from '../../extensions/base/markdown-renderer-extension'
+import type { NodeProcessor } from '../../node-preprocessors/node-processor'
+import type { ComponentReplacer } from '../../replace-components/component-replacer'
+import { TestNodeProcessor } from './test-node-processor'
+import { TestReplacer } from './test-replacer'
+import type MarkdownIt from 'markdown-it'
+import Token from 'markdown-it/lib/token'
+
+export class TestMarkdownRendererExtension extends MarkdownRendererExtension {
+  buildNodeProcessors(): NodeProcessor[] {
+    return [new TestNodeProcessor()]
+  }
+
+  configureMarkdownIt(markdownIt: MarkdownIt) {
+    markdownIt.use(() => {
+      markdownIt.core.ruler.push('configure', (core) => core.tokens.push(new Token('configure', 'configure', 0)))
+      markdownIt.renderer.rules.configure = () => '<span>configure</span>'
+    })
+  }
+
+  buildReplacers(): ComponentReplacer[] {
+    return [new TestReplacer()]
+  }
+
+  buildTagNameAllowList(): string[] {
+    return ['nodeProcessor']
+  }
+
+  configureMarkdownItPost(markdownIt: MarkdownIt) {
+    markdownIt.use(() => {
+      markdownIt.core.ruler.push('post', (core) => core.tokens.push(new Token('post', 'post', 0)))
+      markdownIt.renderer.rules.post = () => '<span>post</span>'
+    })
+  }
+}

frontend/src/components/markdown-renderer/markdown-to-react/test-utils/test-node-processor.ts

@@ -0,0 +1,15 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { NodeProcessor } from '../../node-preprocessors/node-processor'
+import type { Document } from 'domhandler'
+import { Element, Text } from 'domhandler'
+
+export class TestNodeProcessor extends NodeProcessor {
+  process(document: Document): Document {
+    document.childNodes.push(new Element('nodeProcessor', {}, [new Text('node processor children')]))
+    return document
+  }
+}

frontend/src/components/markdown-renderer/markdown-to-react/test-utils/test-replacer.tsx

@@ -0,0 +1,23 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import type { NativeRenderer, NodeReplacement, SubNodeTransform } from '../../replace-components/component-replacer'
+import { ComponentReplacer, DO_NOT_REPLACE } from '../../replace-components/component-replacer'
+import type { Element } from 'domhandler'
+import React, { Fragment } from 'react'
+
+export class TestReplacer extends ComponentReplacer {
+  replace(node: Element, subNodeTransform: SubNodeTransform, nativeRenderer: NativeRenderer): NodeReplacement {
+    return node.tagName === 'nodeProcessor' ? (
+      <Fragment>
+        <span>NodeProcessor! </span>
+        <span data-children={true}> {node.childNodes.map(subNodeTransform)} </span>
+        <span data-native={true}> {nativeRenderer()} </span>
+      </Fragment>
+    ) : (
+      DO_NOT_REPLACE
+    )
+  }
+}

frontend/src/components/markdown-renderer/markdown-to-react/utils/line-content-to-line-id-mapper.test.ts

@@ -3,13 +3,13 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import { LineIdMapper } from './line-id-mapper'
+import { LineContentToLineIdMapper } from './line-content-to-line-id-mapper'
 
 describe('line id mapper', () => {
-  let lineIdMapper: LineIdMapper
+  let lineIdMapper: LineContentToLineIdMapper
 
   beforeEach(() => {
-    lineIdMapper = new LineIdMapper()
+    lineIdMapper = new LineContentToLineIdMapper()
   })
 
   it('should be case sensitive', () => {

frontend/src/components/markdown-renderer/markdown-to-react/utils/line-content-to-line-id-mapper.ts

@@ -3,7 +3,7 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import type { LineWithId } from '../extensions/linemarker/types'
+import type { LineWithId } from '../../extensions/linemarker/types'
 import type { ArrayChange } from 'diff'
 import { diffArrays } from 'diff'
 
@@ -14,7 +14,7 @@ type LineChange = ArrayChange<NewLine | LineWithId>
  * Calculates ids for every line in a given text and memorized the state of the last given text.
  * It also assigns ids for new lines on every update.
  */
-export class LineIdMapper {
+export class LineContentToLineIdMapper {
   private lastLines: LineWithId[] = []
   private lastUsedLineId = 0
 
@@ -58,7 +58,11 @@ export class LineIdMapper {
    */
   private convertChangesToLinesWithIds(changes: LineChange[]): LineWithId[] {
     return changes
-      .filter((change) => LineIdMapper.changeIsNotChangingLines(change) || LineIdMapper.changeIsAddingLines(change))
+      .filter(
+        (change) =>
+          LineContentToLineIdMapper.changeIsNotChangingLines(change) ||
+          LineContentToLineIdMapper.changeIsAddingLines(change)
+      )
       .reduce(
         (previousLineKeys, currentChange) => [...previousLineKeys, ...this.convertChangeToLinesWithIds(currentChange)],
         [] as LineWithId[]
@@ -94,7 +98,7 @@ export class LineIdMapper {
    * @return The created or reused {@link LineWithId lines with ids}
    */
   private convertChangeToLinesWithIds(change: LineChange): LineWithId[] {
-    if (LineIdMapper.changeIsAddingLines(change)) {
+    if (LineContentToLineIdMapper.changeIsAddingLines(change)) {
       return change.value.map((line) => {
         this.lastUsedLineId += 1
         return { line: line, id: this.lastUsedLineId }

frontend/src/components/markdown-renderer/markdown-to-react/utils/node-to-react-transformer.test.tsx

@@ -3,8 +3,8 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import type { NodeReplacement } from '../replace-components/component-replacer'
-import { ComponentReplacer, DO_NOT_REPLACE } from '../replace-components/component-replacer'
+import type { NodeReplacement } from '../../replace-components/component-replacer'
+import { ComponentReplacer, DO_NOT_REPLACE } from '../../replace-components/component-replacer'
 import { NodeToReactTransformer } from './node-to-react-transformer'
 import { Element } from 'domhandler'
 import type { ReactElement, ReactHTMLElement } from 'react'

frontend/src/components/markdown-renderer/markdown-to-react/utils/node-to-react-transformer.tsx

@@ -3,10 +3,14 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import { LinemarkerMarkdownExtension } from '../extensions/linemarker/linemarker-markdown-extension'
-import type { LineWithId } from '../extensions/linemarker/types'
-import type { ComponentReplacer, NodeReplacement, ValidReactDomElement } from '../replace-components/component-replacer'
-import { DO_NOT_REPLACE } from '../replace-components/component-replacer'
+import { LinemarkerMarkdownExtension } from '../../extensions/linemarker/linemarker-markdown-extension'
+import type { LineWithId } from '../../extensions/linemarker/types'
+import type {
+  ComponentReplacer,
+  NodeReplacement,
+  ValidReactDomElement
+} from '../../replace-components/component-replacer'
+import { DO_NOT_REPLACE } from '../../replace-components/component-replacer'
 import { convertNodeToReactElement } from '@hedgedoc/html-to-react/dist/convertNodeToReactElement'
 import { Optional } from '@mrdrogdrog/optional'
 import type { Element, Node } from 'domhandler'

frontend/src/components/markdown-renderer/slideshow-markdown-renderer.tsx

@@ -7,11 +7,11 @@ import type { SlideOptions } from '../../redux/note-details/types/slide-show-opt
 import type { ScrollProps } from '../editor-page/synced-scroll/scroll-props'
 import type { CommonMarkdownRendererProps } from './common-markdown-renderer-props'
 import { RevealMarkdownExtension } from './extensions/reveal/reveal-markdown-extension'
-import { useConvertMarkdownToReactDom } from './hooks/use-convert-markdown-to-react-dom'
 import { useExtractFirstHeadline } from './hooks/use-extract-first-headline'
 import { useMarkdownExtensions } from './hooks/use-markdown-extensions'
 import { REVEAL_STATUS, useReveal } from './hooks/use-reveal'
 import { LoadingSlide } from './loading-slide'
+import { MarkdownToReact } from './markdown-to-react/markdown-to-react'
 import React, { useEffect, useMemo, useRef } from 'react'
 
 export interface SlideshowMarkdownRendererProps extends CommonMarkdownRendererProps {
@@ -25,10 +25,7 @@ export interface SlideshowMarkdownRendererProps extends CommonMarkdownRendererPr
  * @param markdownContentLines The markdown lines
  * @param onFirstHeadingChange The callback to call if the first heading changes.
  * @param onLineMarkerPositionChanged The callback to call with changed {@link LineMarkers}
- * @param onTaskCheckedChange The callback to call if a task is checked or unchecked.
- * @param onTocChange The callback to call if the toc changes.
  * @param baseUrl The base url of the renderer
- * @param onImageClick The callback to call if a image is clicked
  * @param newlinesAreBreaks If newlines are rendered as breaks or not
  * @param slideOptions The {@link SlideOptions} to use
  */
@@ -44,11 +41,9 @@ export const SlideshowMarkdownRenderer: React.FC<SlideshowMarkdownRendererProps
 
   const extensions = useMarkdownExtensions(
     baseUrl,
-    undefined,
     useMemo(() => [new RevealMarkdownExtension()], [])
   )
 
-  const markdownReactDom = useConvertMarkdownToReactDom(markdownContentLines, extensions, newlinesAreBreaks, true)
   const revealStatus = useReveal(markdownContentLines, slideOptions)
 
   const extractFirstHeadline = useExtractFirstHeadline(markdownBodyRef, onFirstHeadingChange)
@@ -59,8 +54,18 @@ export const SlideshowMarkdownRenderer: React.FC<SlideshowMarkdownRendererProps
   }, [extractFirstHeadline, markdownContentLines, revealStatus])
 
   const slideShowDOM = useMemo(
-    () => (revealStatus === REVEAL_STATUS.INITIALISED ? markdownReactDom : <LoadingSlide />),
-    [markdownReactDom, revealStatus]
+    () =>
+      revealStatus === REVEAL_STATUS.INITIALISED ? (
+        <MarkdownToReact
+          markdownContentLines={markdownContentLines}
+          markdownRenderExtensions={extensions}
+          allowHtml={true}
+          newlinesAreBreaks={newlinesAreBreaks}
+        />
+      ) : (
+        <LoadingSlide />
+      ),
+    [extensions, markdownContentLines, newlinesAreBreaks, revealStatus]
   )
 
   return (

frontend/src/components/markdown-renderer/test-utils/test-markdown-renderer.tsx

@@ -5,7 +5,7 @@
  */
 import { StoreProvider } from '../../../redux/store-provider'
 import type { MarkdownRendererExtension } from '../extensions/base/markdown-renderer-extension'
-import { useConvertMarkdownToReactDom } from '../hooks/use-convert-markdown-to-react-dom'
+import { MarkdownToReact } from '../markdown-to-react/markdown-to-react'
 import React, { useMemo } from 'react'
 
 export interface SimpleMarkdownRendererProps {
@@ -21,7 +21,14 @@ export interface SimpleMarkdownRendererProps {
  */
 export const TestMarkdownRenderer: React.FC<SimpleMarkdownRendererProps> = ({ content, extensions }) => {
   const lines = useMemo(() => content.split('\n'), [content])
-  const dom = useConvertMarkdownToReactDom(lines, extensions, true, false)
-
-  return <StoreProvider>{dom}</StoreProvider>
+  return (
+    <StoreProvider>
+      <MarkdownToReact
+        markdownContentLines={lines}
+        markdownRenderExtensions={extensions}
+        newlinesAreBreaks={true}
+        allowHtml={false}
+      />
+    </StoreProvider>
+  )
 }

frontend/src/components/render-page/hooks/sync-scroll/use-document-sync-scrolling.ts

@@ -31,7 +31,7 @@ export const useDocumentSyncScrolling = (
 ): [(lineMarkers: LineMarkerPosition[]) => void, React.UIEventHandler<HTMLElement>] => {
   const [lineMarks, setLineMarks] = useState<LineMarkerPosition[]>()
 
-  const onLineMarkerPositionChanged = useCallback(
+  const recalculateLineMarkerPositions = useCallback(
     (linkMarkerPositions: LineMarkerPosition[]) => {
       if (!outerContainerRef.current || !rendererRef.current) {
         return
@@ -51,5 +51,5 @@ export const useDocumentSyncScrolling = (
   const onUserScroll = useOnUserScroll(lineMarks, outerContainerRef, onScroll)
   useScrollToLineMark(scrollState, lineMarks, numberOfLines, outerContainerRef)
 
-  return useMemo(() => [onLineMarkerPositionChanged, onUserScroll], [onLineMarkerPositionChanged, onUserScroll])
+  return useMemo(() => [recalculateLineMarkerPositions, onUserScroll], [recalculateLineMarkerPositions, onUserScroll])
 }

frontend/src/components/render-page/markdown-document.tsx

@@ -72,7 +72,7 @@ export const MarkdownDocument: React.FC<MarkdownDocumentProps> = ({
   const newlinesAreBreaks = useApplicationState((state) => state.noteDetails.frontmatter.newlinesAreBreaks)
 
   const contentLineCount = useMemo(() => markdownContentLines.length, [markdownContentLines])
-  const [onLineMarkerPositionChanged, onUserScroll] = useDocumentSyncScrolling(
+  const [recalculateLineMarkers, onUserScroll] = useDocumentSyncScrolling(
     internalDocumentRenderPaneRef,
     rendererRef,
     contentLineCount,
@@ -95,7 +95,7 @@ export const MarkdownDocument: React.FC<MarkdownDocumentProps> = ({
           className={`mb-3 ${additionalRendererClasses ?? ''}`}
           markdownContentLines={markdownContentLines}
           onFirstHeadingChange={onFirstHeadingChange}
-          onLineMarkerPositionChanged={onLineMarkerPositionChanged}
+          onLineMarkerPositionChanged={recalculateLineMarkers}
           baseUrl={baseUrl}
           newlinesAreBreaks={newlinesAreBreaks}
         />

frontend/src/extensions/extra-integrations/highlighted-code-fence/hooks/use-code-dom.tsx

@@ -3,11 +3,10 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import convertHtmlToReact from '@hedgedoc/html-to-react'
-import { sanitize } from 'dompurify'
+import { HtmlToReact } from '../../../../components/common/html-to-react/html-to-react'
 import type { HLJSApi } from 'highlight.js'
 import type { ReactElement } from 'react'
-import React, { Fragment, useMemo } from 'react'
+import React, { useMemo } from 'react'
 
 /**
  * Highlights the given code using highlight.js. If the language wasn't recognized then it won't be highlighted.
@@ -38,7 +37,7 @@ export const useCodeDom = (code: string, hljs: HLJSApi | undefined, language?: s
  * @return the code represented as react elements
  */
 const createHtmlLinesToReactDOM = (code: string[]): ReactElement[] => {
-  return code.map((line, lineIndex) => <Fragment key={lineIndex}>{convertHtmlToReact(sanitize(line))}</Fragment>)
+  return code.map((line, lineIndex) => <HtmlToReact htmlCode={line} key={lineIndex} />)
 }
 
 /**

frontend/src/extensions/extra-integrations/plantuml/plantuml-markdown-extension.ts

@@ -20,10 +20,6 @@ import type Token from 'markdown-it/lib/token'
  * @see https://plantuml.com
  */
 export class PlantumlMarkdownExtension extends MarkdownRendererExtension {
-  constructor() {
-    super()
-  }
-
   private plantumlError(markdownIt: MarkdownIt): void {
     const defaultRenderer: Renderer.RenderRule = markdownIt.renderer.rules.fence || (() => '')
     markdownIt.renderer.rules.fence = (tokens: Token[], idx: number, options: Options, env, slf: Renderer) => {