Move markdown split into redux (#1681)

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

cypress/integration/maxLength.spec.ts

@@ -27,9 +27,8 @@ describe('The status bar text length info', () => {
     cy.getById('remainingCharacters').should('have.class', 'text-danger')
   })
 
-  it('shows a warning and opens a modal', () => {
+  it('opens a modal', () => {
     cy.setCodemirrorContent(tooMuchTestContent)
     cy.getById('limitReachedModal').should('be.visible')
-    cy.getIframeBody().findById('limitReachedMessage').should('be.visible')
   })
 })

src/components/document-read-only-page/document-read-only-page-content.tsx

@@ -7,17 +7,17 @@
 import React, { Fragment } from 'react'
 import { useTranslation } from 'react-i18next'
 import { updateNoteTitleByFirstHeading } from '../../redux/note-details/methods'
-import { useNoteMarkdownContentWithoutFrontmatter } from '../../hooks/common/use-note-markdown-content-without-frontmatter'
 import { useApplicationState } from '../../hooks/common/use-application-state'
 import { useSendFrontmatterInfoFromReduxToRenderer } from '../editor-page/renderer-pane/hooks/use-send-frontmatter-info-from-redux-to-renderer'
 import { DocumentInfobar } from './document-infobar'
 import { RenderIframe } from '../editor-page/renderer-pane/render-iframe'
 import { RendererType } from '../render-page/window-post-message-communicator/rendering-message'
+import { useTrimmedNoteMarkdownContentWithoutFrontmatter } from '../../hooks/common/use-trimmed-note-markdown-content-without-frontmatter'
 
 export const DocumentReadOnlyPageContent: React.FC = () => {
   useTranslation()
 
-  const markdownContent = useNoteMarkdownContentWithoutFrontmatter()
+  const markdownContentLines = useTrimmedNoteMarkdownContentWithoutFrontmatter()
   const noteDetails = useApplicationState((state) => state.noteDetails)
   useSendFrontmatterInfoFromReduxToRenderer()
 
@@ -34,7 +34,7 @@ export const DocumentReadOnlyPageContent: React.FC = () => {
       />
       <RenderIframe
         frameClasses={'flex-fill h-100 w-100'}
-        markdownContent={markdownContent}
+        markdownContentLines={markdownContentLines}
         onFirstHeadingChange={updateNoteTitleByFirstHeading}
         rendererType={RendererType.DOCUMENT}
       />

src/components/editor-page/app-bar/help-button/cheatsheet-line.tsx

@@ -4,11 +4,11 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import React, { Suspense, useCallback } from 'react'
+import React, { Suspense, useCallback, useMemo } from 'react'
 import { WaitSpinner } from '../../../common/wait-spinner/wait-spinner'
 
 export interface CheatsheetLineProps {
-  code: string
+  markdown: string
   onTaskCheckedChange: (newValue: boolean) => void
 }
 
@@ -17,7 +17,8 @@ const HighlightedCode = React.lazy(
 )
 const DocumentMarkdownRenderer = React.lazy(() => import('../../../markdown-renderer/document-markdown-renderer'))
 
-export const CheatsheetLine: React.FC<CheatsheetLineProps> = ({ code, onTaskCheckedChange }) => {
+export const CheatsheetLine: React.FC<CheatsheetLineProps> = ({ markdown, onTaskCheckedChange }) => {
+  const lines = useMemo(() => markdown.split('\n'), [markdown])
   const checkboxClick = useCallback(
     (lineInMarkdown: number, newValue: boolean) => {
       onTaskCheckedChange(newValue)
@@ -37,13 +38,13 @@ export const CheatsheetLine: React.FC<CheatsheetLineProps> = ({ code, onTaskChec
       <tr>
         <td>
           <DocumentMarkdownRenderer
-            content={code}
+            markdownContentLines={lines}
             baseUrl={'https://example.org'}
             onTaskCheckedChange={checkboxClick}
           />
         </td>
         <td className={'markdown-body'}>
-          <HighlightedCode code={code} wrapLines={true} startLineNumber={1} language={'markdown'} />
+          <HighlightedCode code={markdown} wrapLines={true} startLineNumber={1} language={'markdown'} />
         </td>
       </tr>
     </Suspense>

src/components/editor-page/app-bar/help-button/cheatsheet-tab-content.tsx

@@ -51,7 +51,7 @@ export const CheatsheetTabContent: React.FC = () => {
       </thead>
       <tbody>
         {codes.map((code) => (
-          <CheatsheetLine code={code} key={code} onTaskCheckedChange={setChecked} />
+          <CheatsheetLine markdown={code} key={code} onTaskCheckedChange={setChecked} />
         ))}
       </tbody>
     </Table>

src/components/editor-page/editor-document-renderer/editor-document-renderer.tsx

@@ -7,10 +7,10 @@
 import React from 'react'
 import type { RenderIframeProps } from '../renderer-pane/render-iframe'
 import { RenderIframe } from '../renderer-pane/render-iframe'
-import { useNoteMarkdownContentWithoutFrontmatter } from '../../../hooks/common/use-note-markdown-content-without-frontmatter'
 import { useSendFrontmatterInfoFromReduxToRenderer } from '../renderer-pane/hooks/use-send-frontmatter-info-from-redux-to-renderer'
+import { useTrimmedNoteMarkdownContentWithoutFrontmatter } from '../../../hooks/common/use-trimmed-note-markdown-content-without-frontmatter'
 
-export type EditorDocumentRendererProps = Omit<RenderIframeProps, 'markdownContent'>
+export type EditorDocumentRendererProps = Omit<RenderIframeProps, 'markdownContentLines'>
 
 /**
  * Renders the markdown content from the global application state with the iframe renderer.
@@ -18,9 +18,8 @@ export type EditorDocumentRendererProps = Omit<RenderIframeProps, 'markdownConte
  * @param props Every property from the {@link RenderIframe} except the markdown content.
  */
 export const EditorDocumentRenderer: React.FC<EditorDocumentRendererProps> = (props) => {
-  const markdownContent = useNoteMarkdownContentWithoutFrontmatter()
-
   useSendFrontmatterInfoFromReduxToRenderer()
+  const trimmedContentLines = useTrimmedNoteMarkdownContentWithoutFrontmatter()
 
-  return <RenderIframe markdownContent={markdownContent} {...props} />
+  return <RenderIframe {...props} markdownContentLines={trimmedContentLines} />
 }

src/components/editor-page/renderer-pane/hooks/use-send-markdown-to-renderer.ts

@@ -11,16 +11,16 @@ import { CommunicationMessageType } from '../../../render-page/window-post-messa
 /**
  * Sends the given markdown content to the renderer.
  *
- * @param markdownContent The markdown content to send.
+ * @param markdownContentLines The markdown content to send.
  */
-export const useSendMarkdownToRenderer = (markdownContent: string): void => {
+export const useSendMarkdownToRenderer = (markdownContentLines: string[]): void => {
   return useSendToRenderer(
     useMemo(
       () => ({
         type: CommunicationMessageType.SET_MARKDOWN_CONTENT,
-        content: markdownContent
+        content: markdownContentLines
       }),
-      [markdownContent]
+      [markdownContentLines]
     )
   )
 }

src/components/editor-page/renderer-pane/render-iframe.tsx

@@ -37,7 +37,7 @@ export interface RenderIframeProps extends RendererProps {
 const log = new Logger('RenderIframe')
 
 export const RenderIframe: React.FC<RenderIframeProps> = ({
-  markdownContent,
+  markdownContentLines,
   onTaskCheckedChange,
   scrollState,
   onFirstHeadingChange,
@@ -133,7 +133,7 @@ export const RenderIframe: React.FC<RenderIframeProps> = ({
   useEffectOnRenderTypeChange(rendererType, onIframeLoad)
   useSendScrollState(scrollState)
   useSendDarkModeStatusToRenderer(forcedDarkMode)
-  useSendMarkdownToRenderer(markdownContent)
+  useSendMarkdownToRenderer(markdownContentLines)
 
   return (
     <Fragment>

src/components/intro-page/hooks/use-intro-page-content.ts

@@ -9,14 +9,14 @@ import { useTranslation } from 'react-i18next'
 import { fetchFrontPageContent } from '../requests'
 import { useCustomizeAssetsUrl } from '../../../hooks/common/use-customize-assets-url'
 
-export const useIntroPageContent = (): string | undefined => {
+export const useIntroPageContent = (): string[] | undefined => {
   const { t } = useTranslation()
-  const [content, setContent] = useState<string | undefined>(undefined)
+  const [content, setContent] = useState<string[] | undefined>(undefined)
   const customizeAssetsUrl = useCustomizeAssetsUrl()
 
   useEffect(() => {
     fetchFrontPageContent(customizeAssetsUrl)
-      .then((content) => setContent(content))
+      .then((content) => setContent(content.split('\n')))
       .catch(() => setContent(undefined))
   }, [customizeAssetsUrl, t])
 

src/components/intro-page/intro-page.tsx

@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import React from 'react'
+import React, { useMemo } from 'react'
 import { Trans } from 'react-i18next'
 import { Branding } from '../common/branding/branding'
 import {
@@ -16,7 +16,6 @@ import { RenderIframe } from '../editor-page/renderer-pane/render-iframe'
 import { CoverButtons } from './cover-buttons/cover-buttons'
 import { FeatureLinks } from './feature-links'
 import { useIntroPageContent } from './hooks/use-intro-page-content'
-import { ShowIf } from '../common/show-if/show-if'
 import { RendererType } from '../render-page/window-post-message-communicator/rendering-message'
 import { WaitSpinner } from '../common/wait-spinner/wait-spinner'
 import { useApplicationState } from '../../hooks/common/use-application-state'
@@ -26,6 +25,25 @@ export const IntroPage: React.FC = () => {
   const introPageContent = useIntroPageContent()
   const rendererReady = useApplicationState((state) => state.rendererStatus.rendererReady)
 
+  const spinner = useMemo(() => {
+    if (!rendererReady && introPageContent !== undefined) {
+      return <WaitSpinner />
+    }
+  }, [introPageContent, rendererReady])
+
+  const introContent = useMemo(() => {
+    if (introPageContent !== undefined) {
+      return (
+        <RenderIframe
+          frameClasses={'w-100 overflow-y-hidden'}
+          markdownContentLines={introPageContent}
+          rendererType={RendererType.INTRO}
+          forcedDarkMode={true}
+        />
+      )
+    }
+  }, [introPageContent])
+
   return (
     <EditorToRendererCommunicatorContextProvider>
       <div className={'flex-fill mt-3'}>
@@ -39,17 +57,8 @@ export const IntroPage: React.FC = () => {
           <Branding delimiter={false} />
         </div>
         <CoverButtons />
-        <ShowIf condition={!rendererReady && introPageContent !== undefined}>
-          <WaitSpinner />
-        </ShowIf>
-        <ShowIf condition={!!introPageContent}>
-          <RenderIframe
-            frameClasses={'w-100 overflow-y-hidden'}
-            markdownContent={introPageContent as string}
-            rendererType={RendererType.INTRO}
-            forcedDarkMode={true}
-          />
-        </ShowIf>
+        {spinner}
+        {introContent}
         <hr className={'mb-5'} />
       </div>
       <FeatureLinks />

src/components/markdown-renderer/common-markdown-renderer-props.ts

@@ -18,5 +18,5 @@ export interface CommonMarkdownRendererProps {
   newlinesAreBreaks?: boolean
   lineOffset?: number
   className?: string
-  content: string
+  markdownContentLines: string[]
 }

src/components/markdown-renderer/document-length-limit-reached-alert.tsx

@@ -1,27 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-import React from 'react'
-import { Alert } from 'react-bootstrap'
-import { Trans, useTranslation } from 'react-i18next'
-import { useApplicationState } from '../../hooks/common/use-application-state'
-import { cypressId } from '../../utils/cypress-attribute'
-import { ShowIf } from '../common/show-if/show-if'
-import type { SimpleAlertProps } from '../common/simple-alert/simple-alert-props'
-
-export const DocumentLengthLimitReachedAlert: React.FC<SimpleAlertProps> = ({ show }) => {
-  useTranslation()
-
-  const maxLength = useApplicationState((state) => state.config.maxDocumentLength)
-
-  return (
-    <ShowIf condition={show}>
-      <Alert variant='danger' dir={'auto'} {...cypressId('limitReachedMessage')}>
-        <Trans i18nKey={'editor.error.limitReached.description'} values={{ maxLength }} />
-      </Alert>
-    </ShowIf>
-  )
-}

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

@@ -4,8 +4,7 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import React, { useMemo, useRef } from 'react'
-import { DocumentLengthLimitReachedAlert } from './document-length-limit-reached-alert'
+import React, { useEffect, useMemo, useRef } from 'react'
 import { useConvertMarkdownToReactDom } from './hooks/use-convert-markdown-to-react-dom'
 import './markdown-renderer.scss'
 import type { LineMarkerPosition } from './markdown-extension/linemarker/types'
@@ -15,7 +14,6 @@ import { useCalculateLineMarkerPosition } from './utils/calculate-line-marker-po
 import { useExtractFirstHeadline } from './hooks/use-extract-first-headline'
 import type { TocAst } from 'markdown-it-toc-done-right'
 import { useOnRefChange } from './hooks/use-on-ref-change'
-import { useTrimmedContent } from './hooks/use-trimmed-content'
 import type { CommonMarkdownRendererProps } from './common-markdown-renderer-props'
 import { useMarkdownExtensions } from './hooks/use-markdown-extensions'
 import { HeadlineAnchorsMarkdownExtension } from './markdown-extension/headline-anchors-markdown-extension'
@@ -26,7 +24,7 @@ export interface DocumentMarkdownRendererProps extends CommonMarkdownRendererPro
 
 export const DocumentMarkdownRenderer: React.FC<DocumentMarkdownRendererProps> = ({
   className,
-  content,
+  markdownContentLines,
   onFirstHeadingChange,
   onLineMarkerPositionChanged,
   onTaskCheckedChange,
@@ -40,7 +38,6 @@ export const DocumentMarkdownRenderer: React.FC<DocumentMarkdownRendererProps> =
   const markdownBodyRef = useRef<HTMLDivElement>(null)
   const currentLineMarkers = useRef<LineMarkers[]>()
   const tocAst = useRef<TocAst>()
-  const [trimmedContent, contentExceedsLimit] = useTrimmedContent(content)
 
   const extensions = useMarkdownExtensions(
     baseUrl,
@@ -51,7 +48,7 @@ export const DocumentMarkdownRenderer: React.FC<DocumentMarkdownRendererProps> =
     onImageClick,
     onTocChange
   )
-  const markdownReactDom = useConvertMarkdownToReactDom(trimmedContent, extensions, newlinesAreBreaks)
+  const markdownReactDom = useConvertMarkdownToReactDom(markdownContentLines, extensions, newlinesAreBreaks)
 
   useTranslation()
   useCalculateLineMarkerPosition(
@@ -60,12 +57,15 @@ export const DocumentMarkdownRenderer: React.FC<DocumentMarkdownRendererProps> =
     onLineMarkerPositionChanged,
     markdownBodyRef.current?.offsetTop ?? 0
   )
-  useExtractFirstHeadline(markdownBodyRef, content, onFirstHeadingChange)
+  const extractFirstHeadline = useExtractFirstHeadline(markdownBodyRef, onFirstHeadingChange)
+  useEffect(() => {
+    extractFirstHeadline()
+  }, [extractFirstHeadline, markdownContentLines])
+
   useOnRefChange(tocAst, onTocChange)
 
   return (
     <div ref={outerContainerRef} className={'position-relative'}>
-      <DocumentLengthLimitReachedAlert show={contentExceedsLimit} />
       <div
         ref={markdownBodyRef}
         className={`${className ?? ''} markdown-body w-100 d-flex flex-column align-items-center`}>

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

@@ -24,7 +24,7 @@ import { SanitizerMarkdownExtension } from '../markdown-extension/sanitizer/sani
  * @return The React DOM that represents the rendered markdown code
  */
 export const useConvertMarkdownToReactDom = (
-  markdownCode: string,
+  markdownContentLines: string[],
   additionalMarkdownExtensions: MarkdownExtension[],
   newlinesAreBreaks?: boolean
 ): ValidReactDomElement[] => {
@@ -63,8 +63,8 @@ export const useConvertMarkdownToReactDom = (
   }, [htmlToReactTransformer, markdownExtensions])
 
   useMemo(() => {
-    htmlToReactTransformer.setLineIds(lineNumberMapper.updateLineMapping(markdownCode))
-  }, [htmlToReactTransformer, lineNumberMapper, markdownCode])
+    htmlToReactTransformer.setLineIds(lineNumberMapper.updateLineMapping(markdownContentLines))
+  }, [htmlToReactTransformer, lineNumberMapper, markdownContentLines])
 
   const nodePreProcessor = useMemo(() => {
     return markdownExtensions
@@ -76,7 +76,7 @@ export const useConvertMarkdownToReactDom = (
   }, [markdownExtensions])
 
   return useMemo(() => {
-    const html = markdownIt.render(markdownCode)
+    const html = markdownIt.render(markdownContentLines.join('\n'))
 
     htmlToReactTransformer.resetReplacers()
 
@@ -84,5 +84,5 @@ export const useConvertMarkdownToReactDom = (
       transform: (node, index) => htmlToReactTransformer.translateNodeToReactElement(node, index),
       preprocessNodes: (document) => nodePreProcessor(document)
     })
-  }, [htmlToReactTransformer, markdownCode, markdownIt, nodePreProcessor])
+  }, [htmlToReactTransformer, markdownContentLines, markdownIt, nodePreProcessor])
 }

src/components/markdown-renderer/hooks/use-extract-first-headline.ts

@@ -5,46 +5,65 @@
  */
 
 import type React from 'react'
-import { useCallback, useEffect, useRef } from 'react'
+import { useCallback, useRef } from 'react'
 
+/**
+ * Extracts the plain text content of a {@link ChildNode node}.
+ *
+ * @param node The node whose text content should be extracted.
+ * @return the plain text content
+ */
+const extractInnerText = (node: ChildNode | null): string => {
+  if (!node) {
+    return ''
+  } else if (isKatexMathMlElement(node)) {
+    return ''
+  } else if (node.childNodes && node.childNodes.length > 0) {
+    return extractInnerTextFromChildren(node)
+  } else if (node.nodeName.toLowerCase() === 'img') {
+    return (node as HTMLImageElement).getAttribute('alt') ?? ''
+  } else {
+    return node.textContent ?? ''
+  }
+}
+
+/**
+ * Determines if the given {@link ChildNode node} is the mathml part of a KaTeX rendering.
+ * @param node The node that might be a katex mathml element
+ */
+const isKatexMathMlElement = (node: ChildNode): boolean => (node as HTMLElement).classList?.contains('katex-mathml')
+
+/**
+ * Extracts the text content of the children of the given {@link ChildNode node}.
+ * @param node The node whose children should be processed. The content of the node itself won't be included.
+ * @return the concatenated text content of the child nodes
+ */
+const extractInnerTextFromChildren = (node: ChildNode): string =>
+  Array.from(node.childNodes).reduce((state, child) => {
+    return state + extractInnerText(child)
+  }, '')
+
+/**
+ * Extracts the plain text content of the first level 1 heading in the document.
+ *
+ * @param documentElement The root element of (sub)dom that should be inspected
+ * @param onFirstHeadingChange A callback that will be executed with the new level 1 heading
+ */
 export const useExtractFirstHeadline = (
   documentElement: React.RefObject<HTMLDivElement>,
-  content: string | undefined,
   onFirstHeadingChange?: (firstHeading: string | undefined) => void
-): void => {
-  const extractInnerText = useCallback((node: ChildNode | null): string => {
-    if (!node) {
-      return ''
-    }
-
-    if ((node as HTMLElement).classList?.contains('katex-mathml')) {
-      return ''
-    }
-
-    let innerText = ''
-
-    if (node.childNodes && node.childNodes.length > 0) {
-      node.childNodes.forEach((child) => {
-        innerText += extractInnerText(child)
-      })
-    } else if (node.nodeName === 'IMG') {
-      innerText += (node as HTMLImageElement).getAttribute('alt')
-    } else {
-      innerText += node.textContent
-    }
-    return innerText
-  }, [])
-
+): (() => void) => {
   const lastFirstHeading = useRef<string | undefined>()
 
-  useEffect(() => {
-    if (onFirstHeadingChange && documentElement.current) {
-      const firstHeading = documentElement.current.getElementsByTagName('h1').item(0)
-      const headingText = extractInnerText(firstHeading).trim()
-      if (headingText !== lastFirstHeading.current) {
-        lastFirstHeading.current = headingText
-        onFirstHeadingChange(headingText)
-      }
+  return useCallback(() => {
+    if (!onFirstHeadingChange || !documentElement.current) {
+      return
     }
-  }, [documentElement, extractInnerText, onFirstHeadingChange, content])
+    const firstHeading = documentElement.current.getElementsByTagName('h1').item(0)
+    const headingText = extractInnerText(firstHeading).trim()
+    if (headingText !== lastFirstHeading.current) {
+      lastFirstHeading.current = headingText
+      onFirstHeadingChange(headingText)
+    }
+  }, [documentElement, onFirstHeadingChange])
 }

src/components/markdown-renderer/hooks/use-reveal.ts

@@ -27,7 +27,7 @@ const initialSlideState: SlideState = {
   indexVertical: 0
 }
 
-export const useReveal = (content: string, slideOptions?: SlideOptions): REVEAL_STATUS => {
+export const useReveal = (markdownContentLines: string[], slideOptions?: SlideOptions): REVEAL_STATUS => {
   const [deck, setDeck] = useState<Reveal>()
   const [revealStatus, setRevealStatus] = useState<REVEAL_STATUS>(REVEAL_STATUS.NOT_INITIALISED)
   const currentSlideState = useRef<SlideState>(initialSlideState)
@@ -67,7 +67,7 @@ export const useReveal = (content: string, slideOptions?: SlideOptions): REVEAL_
     log.debug('Sync deck')
     deck.sync()
     deck.slide(currentSlideState.current.indexHorizontal, currentSlideState.current.indexVertical)
-  }, [content, deck, revealStatus])
+  }, [markdownContentLines, deck, revealStatus])
 
   useEffect(() => {
     if (

src/components/markdown-renderer/hooks/use-trimmed-content.ts

@@ -1,19 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-import { useMemo } from 'react'
-import { useApplicationState } from '../../../hooks/common/use-application-state'
-
-export const useTrimmedContent = (content: string): [trimmedContent: string, contentExceedsLimit: boolean] => {
-  const maxLength = useApplicationState((state) => state.config.maxDocumentLength)
-  const contentExceedsLimit = content.length > maxLength
-
-  const trimmedContent = useMemo(
-    () => (contentExceedsLimit ? content.substr(0, maxLength) : content),
-    [content, contentExceedsLimit, maxLength]
-  )
-  return [trimmedContent, contentExceedsLimit]
-}

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

@@ -4,17 +4,15 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import React, { Fragment, useMemo, useRef } from 'react'
+import React, { useEffect, useMemo, useRef } from 'react'
 import { useConvertMarkdownToReactDom } from './hooks/use-convert-markdown-to-react-dom'
 import './markdown-renderer.scss'
 import { useExtractFirstHeadline } from './hooks/use-extract-first-headline'
 import type { TocAst } from 'markdown-it-toc-done-right'
 import { useOnRefChange } from './hooks/use-on-ref-change'
-import { useTrimmedContent } from './hooks/use-trimmed-content'
 import { REVEAL_STATUS, useReveal } from './hooks/use-reveal'
 import './slideshow.scss'
 import type { ScrollProps } from '../editor-page/synced-scroll/scroll-props'
-import { DocumentLengthLimitReachedAlert } from './document-length-limit-reached-alert'
 import type { CommonMarkdownRendererProps } from './common-markdown-renderer-props'
 import { LoadingSlide } from './loading-slide'
 import { RevealMarkdownExtension } from './markdown-extension/reveal/reveal-markdown-extension'
@@ -27,7 +25,7 @@ export interface SlideshowMarkdownRendererProps extends CommonMarkdownRendererPr
 
 export const SlideshowMarkdownRenderer: React.FC<SlideshowMarkdownRendererProps & ScrollProps> = ({
   className,
-  content,
+  markdownContentLines,
   onFirstHeadingChange,
   onTaskCheckedChange,
   onTocChange,
@@ -39,7 +37,6 @@ export const SlideshowMarkdownRenderer: React.FC<SlideshowMarkdownRendererProps
 }) => {
   const markdownBodyRef = useRef<HTMLDivElement>(null)
   const tocAst = useRef<TocAst>()
-  const [trimmedContent, contentExceedsLimit] = useTrimmedContent(content)
 
   const extensions = useMarkdownExtensions(
     baseUrl,
@@ -51,14 +48,18 @@ export const SlideshowMarkdownRenderer: React.FC<SlideshowMarkdownRendererProps
     onTocChange
   )
 
-  const markdownReactDom = useConvertMarkdownToReactDom(trimmedContent, extensions, newlinesAreBreaks)
-  const revealStatus = useReveal(content, slideOptions)
+  const markdownReactDom = useConvertMarkdownToReactDom(markdownContentLines, extensions, newlinesAreBreaks)
+  const revealStatus = useReveal(markdownContentLines, slideOptions)
+
+  useExtractFirstHeadline(markdownBodyRef, onFirstHeadingChange)
+
+  const extractFirstHeadline = useExtractFirstHeadline(markdownBodyRef, onFirstHeadingChange)
+  useEffect(() => {
+    if (revealStatus === REVEAL_STATUS.INITIALISED) {
+      extractFirstHeadline()
+    }
+  }, [extractFirstHeadline, markdownContentLines, revealStatus])
 
-  useExtractFirstHeadline(
-    markdownBodyRef,
-    revealStatus === REVEAL_STATUS.INITIALISED ? content : undefined,
-    onFirstHeadingChange
-  )
   useOnRefChange(tocAst, onTocChange)
 
   const slideShowDOM = useMemo(
@@ -67,14 +68,11 @@ export const SlideshowMarkdownRenderer: React.FC<SlideshowMarkdownRendererProps
   )
 
   return (
-    <Fragment>
-      <DocumentLengthLimitReachedAlert show={contentExceedsLimit} />
-      <div className={'reveal'}>
-        <div ref={markdownBodyRef} className={`${className ?? ''} slides`}>
-          {slideShowDOM}
-        </div>
+    <div className={'reveal'}>
+      <div ref={markdownBodyRef} className={`${className ?? ''} slides`}>
+        {slideShowDOM}
       </div>
-    </Fragment>
+    </div>
   )
 }
 

src/components/markdown-renderer/utils/line-id-mapper.test.ts

@@ -14,8 +14,8 @@ describe('line id mapper', () => {
   })
 
   it('should be case sensitive', () => {
-    lineIdMapper.updateLineMapping('this\nis\ntext')
-    expect(lineIdMapper.updateLineMapping('this\nis\nText')).toEqual([
+    lineIdMapper.updateLineMapping(['this', 'is', 'text'])
+    expect(lineIdMapper.updateLineMapping(['this', 'is', 'Text'])).toEqual([
       {
         line: 'this',
         id: 1
@@ -32,8 +32,8 @@ describe('line id mapper', () => {
   })
 
   it('should not update line ids of shifted lines', () => {
-    lineIdMapper.updateLineMapping('this\nis\ntext')
-    expect(lineIdMapper.updateLineMapping('this\nis\nmore\ntext')).toEqual([
+    lineIdMapper.updateLineMapping(['this', 'is', 'text'])
+    expect(lineIdMapper.updateLineMapping(['this', 'is', 'more', 'text'])).toEqual([
       {
         line: 'this',
         id: 1
@@ -54,8 +54,8 @@ describe('line id mapper', () => {
   })
 
   it('should not update line ids if nothing changes', () => {
-    lineIdMapper.updateLineMapping('this\nis\ntext')
-    expect(lineIdMapper.updateLineMapping('this\nis\ntext')).toEqual([
+    lineIdMapper.updateLineMapping(['this', 'is', 'text'])
+    expect(lineIdMapper.updateLineMapping(['this', 'is', 'text'])).toEqual([
       {
         line: 'this',
         id: 1
@@ -72,9 +72,9 @@ describe('line id mapper', () => {
   })
 
   it('should not reuse line ids of removed lines', () => {
-    lineIdMapper.updateLineMapping('this\nis\nold')
-    lineIdMapper.updateLineMapping('this\nis')
-    expect(lineIdMapper.updateLineMapping('this\nis\nnew')).toEqual([
+    lineIdMapper.updateLineMapping(['this', 'is', 'old'])
+    lineIdMapper.updateLineMapping(['this', 'is'])
+    expect(lineIdMapper.updateLineMapping(['this', 'is', 'new'])).toEqual([
       {
         line: 'this',
         id: 1
@@ -91,8 +91,8 @@ describe('line id mapper', () => {
   })
 
   it('should update line ids for changed lines', () => {
-    lineIdMapper.updateLineMapping('this\nis\nold')
-    expect(lineIdMapper.updateLineMapping('this\nis\nnew')).toEqual([
+    lineIdMapper.updateLineMapping(['this', 'is', 'old'])
+    expect(lineIdMapper.updateLineMapping(['this', 'is', 'new'])).toEqual([
       {
         line: 'this',
         id: 1

src/components/markdown-renderer/utils/line-id-mapper.ts

@@ -23,12 +23,11 @@ export class LineIdMapper {
    * Calculates a line id mapping for the given line based text by creating a diff
    * with the last lines code.
    *
-   * @param newText The new text for which the line ids should be calculated
+   * @param newMarkdownContentLines The markdown content for which the line ids should be calculated
    * @return the calculated {@link LineWithId lines with unique ids}
    */
-  public updateLineMapping(newText: string): LineWithId[] {
-    const lines = newText.split('\n')
-    const lineDifferences = this.diffNewLinesWithLastLineKeys(lines)
+  public updateLineMapping(newMarkdownContentLines: string[]): LineWithId[] {
+    const lineDifferences = this.diffNewLinesWithLastLineKeys(newMarkdownContentLines)
     const newLineKeys = this.convertChangesToLinesWithIds(lineDifferences)
     this.lastLines = newLineKeys
     return newLineKeys

src/components/render-page/iframe-markdown-renderer.tsx

@@ -20,7 +20,7 @@ import { initialState } from '../../redux/note-details/initial-state'
 import type { RendererFrontmatterInfo } from '../../redux/note-details/types/note-details'
 
 export const IframeMarkdownRenderer: React.FC = () => {
-  const [markdownContent, setMarkdownContent] = useState('')
+  const [markdownContentLines, setMarkdownContentLines] = useState<string[]>([])
   const [scrollState, setScrollState] = useState<ScrollState>({ firstLineInView: 1, scrolledPercentage: 0 })
   const [baseConfiguration, setBaseConfiguration] = useState<BaseConfiguration | undefined>(undefined)
   const [frontmatterInfo, setFrontmatterInfo] = useState<RendererFrontmatterInfo>(initialState.frontmatterRendererInfo)
@@ -39,7 +39,7 @@ export const IframeMarkdownRenderer: React.FC = () => {
     setBaseConfiguration(values.baseConfiguration)
   )
   useRendererReceiveHandler(CommunicationMessageType.SET_MARKDOWN_CONTENT, (values) =>
-    setMarkdownContent(values.content)
+    setMarkdownContentLines(values.content)
   )
   useRendererReceiveHandler(CommunicationMessageType.SET_DARKMODE, (values) => setDarkMode(values.activated))
   useRendererReceiveHandler(CommunicationMessageType.SET_SCROLL_STATE, (values) => setScrollState(values.scrollState))
@@ -106,7 +106,7 @@ export const IframeMarkdownRenderer: React.FC = () => {
       return (
         <MarkdownDocument
           additionalOuterContainerClasses={'vh-100 bg-light'}
-          markdownContent={markdownContent}
+          markdownContentLines={markdownContentLines}
           onTaskCheckedChange={onTaskCheckedChange}
           onFirstHeadingChange={onFirstHeadingChange}
           onMakeScrollSource={onMakeScrollSource}
@@ -120,7 +120,7 @@ export const IframeMarkdownRenderer: React.FC = () => {
     case RendererType.SLIDESHOW:
       return (
         <SlideshowMarkdownRenderer
-          content={markdownContent}
+          markdownContentLines={markdownContentLines}
           baseUrl={baseConfiguration.baseUrl}
           onFirstHeadingChange={onFirstHeadingChange}
           onImageClick={onImageClick}
@@ -133,7 +133,7 @@ export const IframeMarkdownRenderer: React.FC = () => {
       return (
         <MarkdownDocument
           additionalOuterContainerClasses={'vh-100 bg-light overflow-y-hidden'}
-          markdownContent={markdownContent}
+          markdownContentLines={markdownContentLines}
           baseUrl={baseConfiguration.baseUrl}
           onImageClick={onImageClick}
           disableToc={true}

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

@@ -24,7 +24,7 @@ export interface RendererProps extends ScrollProps {
   onFirstHeadingChange?: (firstHeading: string | undefined) => void
   onTaskCheckedChange?: (lineInMarkdown: number, checked: boolean) => void
   documentRenderPaneRef?: MutableRefObject<HTMLDivElement | null>
-  markdownContent: string
+  markdownContentLines: string[]
   onImageClick?: ImageClickHandler
   onHeightChange?: (height: number) => void
 }
@@ -44,7 +44,7 @@ export const MarkdownDocument: React.FC<MarkdownDocumentProps> = ({
   onMakeScrollSource,
   onTaskCheckedChange,
   baseUrl,
-  markdownContent,
+  markdownContentLines,
   onImageClick,
   onScroll,
   scrollState,
@@ -70,7 +70,7 @@ export const MarkdownDocument: React.FC<MarkdownDocumentProps> = ({
     onHeightChange(rendererSize.height ? rendererSize.height + 1 : 0)
   }, [rendererSize.height, onHeightChange])
 
-  const contentLineCount = useMemo(() => markdownContent.split('\n').length, [markdownContent])
+  const contentLineCount = useMemo(() => markdownContentLines.length, [markdownContentLines])
   const [onLineMarkerPositionChanged, onUserScroll] = useDocumentSyncScrolling(
     internalDocumentRenderPaneRef,
     rendererRef,
@@ -92,7 +92,7 @@ export const MarkdownDocument: React.FC<MarkdownDocumentProps> = ({
         <DocumentMarkdownRenderer
           outerContainerRef={rendererRef}
           className={`mb-3 ${additionalRendererClasses ?? ''}`}
-          content={markdownContent}
+          markdownContentLines={markdownContentLines}
           onFirstHeadingChange={onFirstHeadingChange}
           onLineMarkerPositionChanged={onLineMarkerPositionChanged}
           onTaskCheckedChange={onTaskCheckedChange}

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

@@ -62,7 +62,7 @@ export interface ImageClickedMessage {
 
 export interface SetMarkdownContentMessage {
   type: CommunicationMessageType.SET_MARKDOWN_CONTENT
-  content: string
+  content: string[]
 }
 
 export interface SetScrollStateMessage {

src/components/slide-show-page/slide-show-page-content.tsx

@@ -10,10 +10,10 @@ import { RenderIframe } from '../editor-page/renderer-pane/render-iframe'
 import { updateNoteTitleByFirstHeading } from '../../redux/note-details/methods'
 import { useTranslation } from 'react-i18next'
 import { useSendFrontmatterInfoFromReduxToRenderer } from '../editor-page/renderer-pane/hooks/use-send-frontmatter-info-from-redux-to-renderer'
-import { useNoteMarkdownContentWithoutFrontmatter } from '../../hooks/common/use-note-markdown-content-without-frontmatter'
+import { useTrimmedNoteMarkdownContentWithoutFrontmatter } from '../../hooks/common/use-trimmed-note-markdown-content-without-frontmatter'
 
 export const SlideShowPageContent: React.FC = () => {
-  const markdownContent = useNoteMarkdownContentWithoutFrontmatter()
+  const markdownContentLines = useTrimmedNoteMarkdownContentWithoutFrontmatter()
   useTranslation()
   useSendFrontmatterInfoFromReduxToRenderer()
 
@@ -21,7 +21,7 @@ export const SlideShowPageContent: React.FC = () => {
     <div className={'vh-100 vw-100'}>
       <RenderIframe
         frameClasses={'h-100 w-100'}
-        markdownContent={markdownContent}
+        markdownContentLines={markdownContentLines}
         rendererType={RendererType.SLIDESHOW}
         onFirstHeadingChange={updateNoteTitleByFirstHeading}
       />

src/hooks/common/use-note-markdown-content-without-frontmatter.ts

@@ -1,20 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-import { useNoteMarkdownContent } from './use-note-markdown-content'
-import { useApplicationState } from './use-application-state'
-import { useMemo } from 'react'
-
-/**
- * Extracts the markdown content of the current note from the global application state and removes the frontmatter.
- * @return the markdown content of the note without frontmatter
- */
-export const useNoteMarkdownContentWithoutFrontmatter = (): string => {
-  const markdownContent = useNoteMarkdownContent()
-  const lineOffset = useApplicationState((state) => state.noteDetails.frontmatterRendererInfo.lineOffset)
-
-  return useMemo(() => markdownContent.split('\n').slice(lineOffset).join('\n'), [markdownContent, lineOffset])
-}

src/hooks/common/use-trimmed-note-markdown-content-without-frontmatter.ts

@@ -0,0 +1,28 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { useMemo } from 'react'
+import { useApplicationState } from './use-application-state'
+import { useNoteMarkdownContent } from './use-note-markdown-content'
+
+export const useTrimmedNoteMarkdownContentWithoutFrontmatter = (): string[] => {
+  const maxLength = useApplicationState((state) => state.config.maxDocumentLength)
+  const markdownContent = useNoteMarkdownContent()
+  const markdownContentLines = useApplicationState((state) => state.noteDetails.markdownContentLines)
+  const lineOffset = useApplicationState((state) => state.noteDetails.frontmatterRendererInfo.lineOffset)
+
+  const trimmedLines = useMemo(() => {
+    if (markdownContent.length > maxLength) {
+      return markdownContent.slice(0, maxLength).split('\n')
+    } else {
+      return markdownContentLines
+    }
+  }, [markdownContent, markdownContentLines, maxLength])
+
+  return useMemo(() => {
+    return trimmedLines.slice(lineOffset)
+  }, [lineOffset, trimmedLines])
+}

src/redux/note-details/frontmatter-extractor/extractor.test.ts

@@ -10,47 +10,47 @@ import type { PresentFrontmatterExtractionResult } from './types'
 describe('frontmatter extraction', () => {
   describe('isPresent property', () => {
     it('is false when note does not contain three dashes at all', () => {
-      const testNote = 'abcdef\nmore text'
+      const testNote = ['abcdef', 'more text']
       const extraction = extractFrontmatter(testNote)
       expect(extraction.isPresent).toBe(false)
     })
     it('is false when note does not start with three dashes', () => {
-      const testNote = '\n---\nthis is not frontmatter'
+      const testNote = ['', '---', 'this is not frontmatter']
       const extraction = extractFrontmatter(testNote)
       expect(extraction.isPresent).toBe(false)
     })
     it('is false when note start with less than three dashes', () => {
-      const testNote = '--\nthis is not frontmatter'
+      const testNote = ['--', 'this is not frontmatter']
       const extraction = extractFrontmatter(testNote)
       expect(extraction.isPresent).toBe(false)
     })
     it('is false when note starts with three dashes but contains other characters in the same line', () => {
-      const testNote = '--- a\nthis is not frontmatter'
+      const testNote = ['--- a', 'this is not frontmatter']
       const extraction = extractFrontmatter(testNote)
       expect(extraction.isPresent).toBe(false)
     })
     it('is false when note has no ending marker for frontmatter', () => {
-      const testNote = '---\nthis is not frontmatter\nbecause\nthere is no\nend marker'
+      const testNote = ['---', 'this is not frontmatter', 'because', 'there is no', 'end marker']
       const extraction = extractFrontmatter(testNote)
       expect(extraction.isPresent).toBe(false)
     })
     it('is false when note end marker is present but with not the same amount of dashes as start marker', () => {
-      const testNote = '---\nthis is not frontmatter\n----\ncontent'
+      const testNote = ['---', 'this is not frontmatter', '----', 'content']
       const extraction = extractFrontmatter(testNote)
       expect(extraction.isPresent).toBe(false)
     })
     it('is true when note end marker is present with the same amount of dashes as start marker', () => {
-      const testNote = '---\nthis is frontmatter\n---\ncontent'
+      const testNote = ['---', 'this is frontmatter', '---', 'content']
       const extraction = extractFrontmatter(testNote)
       expect(extraction.isPresent).toBe(true)
     })
     it('is true when note end marker is present with the same amount of dashes as start marker but without content', () => {
-      const testNote = '---\nthis is frontmatter\n---'
+      const testNote = ['---', 'this is frontmatter', '---']
       const extraction = extractFrontmatter(testNote)
       expect(extraction.isPresent).toBe(true)
     })
     it('is true when note end marker is present with the same amount of dots as start marker', () => {
-      const testNote = '---\nthis is frontmatter\n...\ncontent'
+      const testNote = ['---', 'this is frontmatter', '...', 'content']
       const extraction = extractFrontmatter(testNote)
       expect(extraction.isPresent).toBe(true)
     })
@@ -58,22 +58,22 @@ describe('frontmatter extraction', () => {
 
   describe('lineOffset property', () => {
     it('is correct for single line frontmatter without content', () => {
-      const testNote = '---\nsingle line frontmatter\n...'
+      const testNote = ['---', 'single line frontmatter', '...']
       const extraction = extractFrontmatter(testNote) as PresentFrontmatterExtractionResult
       expect(extraction.lineOffset).toEqual(3)
     })
     it('is correct for single line frontmatter with content', () => {
-      const testNote = '---\nsingle line frontmatter\n...\ncontent'
+      const testNote = ['---', 'single line frontmatter', '...', 'content']
       const extraction = extractFrontmatter(testNote) as PresentFrontmatterExtractionResult
       expect(extraction.lineOffset).toEqual(3)
     })
     it('is correct for multi-line frontmatter without content', () => {
-      const testNote = '---\nabc\n123\ndef\n...'
+      const testNote = ['---', 'abc', '123', 'def', '...']
       const extraction = extractFrontmatter(testNote) as PresentFrontmatterExtractionResult
       expect(extraction.lineOffset).toEqual(5)
     })
     it('is correct for multi-line frontmatter with content', () => {
-      const testNote = '---\nabc\n123\ndef\n...\ncontent'
+      const testNote = ['---', 'abc', '123', 'def', '...', 'content']
       const extraction = extractFrontmatter(testNote) as PresentFrontmatterExtractionResult
       expect(extraction.lineOffset).toEqual(5)
     })
@@ -81,12 +81,12 @@ describe('frontmatter extraction', () => {
 
   describe('rawText property', () => {
     it('contains single-line frontmatter text', () => {
-      const testNote = '---\nsingle-line\n...\ncontent'
+      const testNote = ['---', 'single-line', '...', 'content']
       const extraction = extractFrontmatter(testNote) as PresentFrontmatterExtractionResult
       expect(extraction.rawText).toEqual('single-line')
     })
     it('contains multi-line frontmatter text', () => {
-      const testNote = '---\nmulti\nline\n...\ncontent'
+      const testNote = ['---', 'multi', 'line', '...', 'content']
       const extraction = extractFrontmatter(testNote) as PresentFrontmatterExtractionResult
       expect(extraction.rawText).toEqual('multi\nline')
     })

src/redux/note-details/frontmatter-extractor/extractor.ts

@@ -12,14 +12,13 @@ const FRONTMATTER_END_REGEX = /^(?:-{3,}|\.{3,})$/
  * Extracts a frontmatter block from a given multiline string.
  * A valid frontmatter block requires the content to start with a line containing at least three dashes.
  * The block is terminated by a line containing the same amount of dashes or dots as the first line.
- * @param content The multiline string from which the frontmatter should be extracted.
+ * @param lines The lines from which the frontmatter should be extracted.
  * @return { isPresent } false if no frontmatter block could be found, true if a block was found.
  *         { rawFrontmatterText } if a block was found, this property contains the extracted text without the fencing.
  *         { frontmatterLines }   if a block was found, this property contains the number of lines to skip from the
  *                                given multiline string for retrieving the non-frontmatter content.
  */
-export const extractFrontmatter = (content: string): FrontmatterExtractionResult => {
-  const lines = content.split('\n')
+export const extractFrontmatter = (lines: string[]): FrontmatterExtractionResult => {
   if (lines.length < 2 || !FRONTMATTER_BEGIN_REGEX.test(lines[0])) {
     return {
       isPresent: false

src/redux/note-details/initial-state.ts

@@ -19,6 +19,7 @@ export const initialSlideOptions: SlideOptions = {
 
 export const initialState: NoteDetails = {
   markdownContent: '',
+  markdownContentLines: [],
   rawFrontmatter: '',
   frontmatterRendererInfo: {
     frontmatterInvalid: false,

src/redux/note-details/reducer.ts

@@ -74,7 +74,7 @@ const buildStateFromTaskListUpdate = (
   changedLine: number,
   checkboxChecked: boolean
 ): NoteDetails => {
-  const lines = state.markdownContent.split('\n')
+  const lines = state.markdownContentLines
   const results = TASK_REGEX.exec(lines[changedLine])
   if (results) {
     const before = results[1]
@@ -88,23 +88,26 @@ const buildStateFromTaskListUpdate = (
 /**
  * Builds a {@link NoteDetails} redux state from a fresh document content.
  * @param state The previous redux state.
- * @param markdownContent The fresh document content consisting of the frontmatter and markdown part.
+ * @param newMarkdownContent The fresh document content consisting of the frontmatter and markdown part.
  * @return An updated {@link NoteDetails} redux state.
  */
-const buildStateFromMarkdownContentUpdate = (state: NoteDetails, markdownContent: string): NoteDetails => {
-  const frontmatterExtraction = extractFrontmatter(markdownContent)
+const buildStateFromMarkdownContentUpdate = (state: NoteDetails, newMarkdownContent: string): NoteDetails => {
+  const markdownContentLines = newMarkdownContent.split('\n')
+  const frontmatterExtraction = extractFrontmatter(markdownContentLines)
   if (frontmatterExtraction.isPresent) {
     return buildStateFromFrontmatterUpdate(
       {
         ...state,
-        markdownContent: markdownContent
+        markdownContent: newMarkdownContent,
+        markdownContentLines: markdownContentLines
       },
       frontmatterExtraction
     )
   } else {
     return {
       ...state,
-      markdownContent: markdownContent,
+      markdownContent: newMarkdownContent,
+      markdownContentLines: markdownContentLines,
       rawFrontmatter: '',
       noteTitle: generateNoteTitle(initialState.frontmatter, state.firstHeading),
       frontmatter: initialState.frontmatter,
@@ -193,6 +196,7 @@ const generateNoteTitle = (frontmatter: NoteFrontmatter, firstHeading?: string)
 const convertNoteDtoToNoteDetails = (note: NoteDto): NoteDetails => {
   return {
     markdownContent: note.content,
+    markdownContentLines: note.content.split('\n'),
     rawFrontmatter: '',
     frontmatterRendererInfo: initialState.frontmatterRendererInfo,
     frontmatter: initialState.frontmatter,

src/redux/note-details/types/note-details.ts

@@ -13,6 +13,7 @@ import type { ISO6391 } from './iso6391'
  */
 export interface NoteDetails {
   markdownContent: string
+  markdownContentLines: string[]
   rawFrontmatter: string
   frontmatter: NoteFrontmatter
   frontmatterRendererInfo: RendererFrontmatterInfo