Move frontmatter extraction from renderer to redux (#1413)

package.json

@@ -63,7 +63,6 @@
     "markdown-it-deflist": "2.1.0",
     "markdown-it-emoji": "2.0.0",
     "markdown-it-footnote": "3.0.3",
-    "markdown-it-front-matter": "0.2.3",
     "markdown-it-imsize": "2.0.1",
     "markdown-it-ins": "3.0.1",
     "markdown-it-mark": "3.0.1",

src/api/notes/dto-methods.ts

@@ -1,28 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-import { NoteDto } from './types'
-import { NoteDetails } from '../../redux/note-details/types'
-import { DateTime } from 'luxon'
-import { initialState } from '../../redux/note-details/reducers'
-
-export const noteDtoToNoteDetails = (note: NoteDto): NoteDetails => {
-  return {
-    markdownContent: note.content,
-    frontmatter: initialState.frontmatter,
-    id: note.metadata.id,
-    noteTitle: initialState.noteTitle,
-    createTime: DateTime.fromISO(note.metadata.createTime),
-    lastChange: {
-      userName: note.metadata.updateUser.userName,
-      timestamp: DateTime.fromISO(note.metadata.updateTime)
-    },
-    firstHeading: initialState.firstHeading,
-    viewCount: note.metadata.viewCount,
-    alias: note.metadata.alias,
-    authorship: note.metadata.editedBy
-  }
-}

src/components/common/note-frontmatter/extract-frontmatter.test.ts

@@ -0,0 +1,94 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { extractFrontmatter } from './extract-frontmatter'
+import { PresentFrontmatterExtractionResult } from './types'
+
+describe('frontmatter extraction', () => {
+  describe('frontmatterPresent property', () => {
+    it('is false when note does not contain three dashes at all', () => {
+      const testNote = 'abcdef\nmore text'
+      const extraction = extractFrontmatter(testNote)
+      expect(extraction.frontmatterPresent).toBe(false)
+    })
+    it('is false when note does not start with three dashes', () => {
+      const testNote = '\n---\nthis is not frontmatter'
+      const extraction = extractFrontmatter(testNote)
+      expect(extraction.frontmatterPresent).toBe(false)
+    })
+    it('is false when note start with less than three dashes', () => {
+      const testNote = '--\nthis is not frontmatter'
+      const extraction = extractFrontmatter(testNote)
+      expect(extraction.frontmatterPresent).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 extraction = extractFrontmatter(testNote)
+      expect(extraction.frontmatterPresent).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 extraction = extractFrontmatter(testNote)
+      expect(extraction.frontmatterPresent).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 extraction = extractFrontmatter(testNote)
+      expect(extraction.frontmatterPresent).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 extraction = extractFrontmatter(testNote)
+      expect(extraction.frontmatterPresent).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 extraction = extractFrontmatter(testNote)
+      expect(extraction.frontmatterPresent).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 extraction = extractFrontmatter(testNote)
+      expect(extraction.frontmatterPresent).toBe(true)
+    })
+  })
+
+  describe('frontmatterLines property', () => {
+    it('is correct for single line frontmatter without content', () => {
+      const testNote = '---\nsingle line frontmatter\n...'
+      const extraction = extractFrontmatter(testNote) as PresentFrontmatterExtractionResult
+      expect(extraction.frontmatterLines).toEqual(3)
+    })
+    it('is correct for single line frontmatter with content', () => {
+      const testNote = '---\nsingle line frontmatter\n...\ncontent'
+      const extraction = extractFrontmatter(testNote) as PresentFrontmatterExtractionResult
+      expect(extraction.frontmatterLines).toEqual(3)
+    })
+    it('is correct for multi-line frontmatter without content', () => {
+      const testNote = '---\nabc\n123\ndef\n...'
+      const extraction = extractFrontmatter(testNote) as PresentFrontmatterExtractionResult
+      expect(extraction.frontmatterLines).toEqual(5)
+    })
+    it('is correct for multi-line frontmatter with content', () => {
+      const testNote = '---\nabc\n123\ndef\n...\ncontent'
+      const extraction = extractFrontmatter(testNote) as PresentFrontmatterExtractionResult
+      expect(extraction.frontmatterLines).toEqual(5)
+    })
+  })
+
+  describe('rawFrontmatterText property', () => {
+    it('contains single-line frontmatter text', () => {
+      const testNote = '---\nsingle-line\n...\ncontent'
+      const extraction = extractFrontmatter(testNote) as PresentFrontmatterExtractionResult
+      expect(extraction.rawFrontmatterText).toEqual('single-line')
+    })
+    it('contains multi-line frontmatter text', () => {
+      const testNote = '---\nmulti\nline\n...\ncontent'
+      const extraction = extractFrontmatter(testNote) as PresentFrontmatterExtractionResult
+      expect(extraction.rawFrontmatterText).toEqual('multi\nline')
+    })
+  })
+})

src/components/common/note-frontmatter/extract-frontmatter.ts

@@ -0,0 +1,40 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { FrontmatterExtractionResult } from './types'
+
+const FRONTMATTER_BEGIN_REGEX = /^-{3,}$/
+const FRONTMATTER_END_REGEX = /^(?:-{3,}|\.{3,})$/
+
+/**
+ * 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.
+ * @return { frontmatterPresent } 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')
+  if (lines.length < 2 || !FRONTMATTER_BEGIN_REGEX.test(lines[0])) {
+    return {
+      frontmatterPresent: false
+    }
+  }
+  for (let i = 1; i < lines.length; i++) {
+    if (lines[i].length === lines[0].length && FRONTMATTER_END_REGEX.test(lines[i])) {
+      return {
+        frontmatterPresent: true,
+        rawFrontmatterText: lines.slice(1, i).join('\n'),
+        frontmatterLines: i + 1
+      }
+    }
+  }
+  return {
+    frontmatterPresent: false
+  }
+}

src/components/common/note-frontmatter/note-frontmatter.test.ts

@@ -0,0 +1,68 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { NoteFrontmatter } from './note-frontmatter'
+
+describe('yaml frontmatter', () => {
+  it('should parse "title"', () => {
+    const noteFrontmatter = NoteFrontmatter.createFromYaml('title: test')
+    expect(noteFrontmatter.title).toEqual('test')
+  })
+
+  it('should parse "robots"', () => {
+    const noteFrontmatter = NoteFrontmatter.createFromYaml('robots: index, follow')
+    expect(noteFrontmatter.robots).toEqual('index, follow')
+  })
+
+  it('should parse the deprecated tags syntax', () => {
+    const noteFrontmatter = NoteFrontmatter.createFromYaml('tags: test123, abc')
+    expect(noteFrontmatter.tags).toEqual(['test123', 'abc'])
+    expect(noteFrontmatter.deprecatedTagsSyntax).toEqual(true)
+  })
+
+  it('should parse the tags list syntax', () => {
+    const noteFrontmatter = NoteFrontmatter.createFromYaml(`tags:
+      - test123
+      - abc
+    `)
+    expect(noteFrontmatter.tags).toEqual(['test123', 'abc'])
+    expect(noteFrontmatter.deprecatedTagsSyntax).toEqual(false)
+  })
+
+  it('should parse the tag inline-list syntax', () => {
+    const noteFrontmatter = NoteFrontmatter.createFromYaml("tags: ['test123', 'abc']")
+    expect(noteFrontmatter.tags).toEqual(['test123', 'abc'])
+    expect(noteFrontmatter.deprecatedTagsSyntax).toEqual(false)
+  })
+
+  it('should parse "breaks"', () => {
+    const noteFrontmatter = NoteFrontmatter.createFromYaml('breaks: false')
+    expect(noteFrontmatter.breaks).toEqual(false)
+  })
+
+  it('should parse an empty opengraph object', () => {
+    const noteFrontmatter = NoteFrontmatter.createFromYaml('opengraph:')
+    expect(noteFrontmatter.opengraph).toEqual(new Map<string, string>())
+  })
+
+  it('should parse an opengraph title', () => {
+    const noteFrontmatter = NoteFrontmatter.createFromYaml(`opengraph:
+      title: Testtitle
+    `)
+    expect(noteFrontmatter.opengraph.get('title')).toEqual('Testtitle')
+  })
+
+  it('should parse multiple opengraph values', () => {
+    const noteFrontmatter = NoteFrontmatter.createFromYaml(`opengraph:
+      title: Testtitle
+      image: https://dummyimage.com/48.png
+      image:type: image/png
+    `)
+    expect(noteFrontmatter.opengraph.get('title')).toEqual('Testtitle')
+    expect(noteFrontmatter.opengraph.get('image')).toEqual('https://dummyimage.com/48.png')
+    expect(noteFrontmatter.opengraph.get('image:type')).toEqual('image/png')
+  })
+})

src/components/common/note-frontmatter/note-frontmatter.ts

@@ -0,0 +1,70 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+// import { RevealOptions } from 'reveal.js'
+import { load } from 'js-yaml'
+import { ISO6391, NoteTextDirection, NoteType, RawNoteFrontmatter } from './types'
+
+/**
+ * Class that represents the parsed frontmatter metadata of a note.
+ */
+export class NoteFrontmatter {
+  title: string
+  description: string
+  tags: string[]
+  deprecatedTagsSyntax: boolean
+  robots: string
+  lang: typeof ISO6391[number]
+  dir: NoteTextDirection
+  breaks: boolean
+  GA: string
+  disqus: string
+  type: NoteType
+  opengraph: Map<string, string>
+
+  /**
+   * Creates a new frontmatter metadata instance based on the given raw metadata properties.
+   * @param rawData A {@link RawNoteFrontmatter} object containing the properties of the parsed yaml frontmatter.
+   */
+  constructor(rawData: RawNoteFrontmatter) {
+    this.title = rawData.title ?? ''
+    this.description = rawData.description ?? ''
+    this.robots = rawData.robots ?? ''
+    this.breaks = rawData.breaks ?? true
+    this.GA = rawData.GA ?? ''
+    this.disqus = rawData.disqus ?? ''
+    this.lang = (rawData.lang ? ISO6391.find((lang) => lang === rawData.lang) : undefined) ?? 'en'
+    this.type =
+      (rawData.type ? Object.values(NoteType).find((type) => type === rawData.type) : undefined) ?? NoteType.DOCUMENT
+    this.dir =
+      (rawData.dir ? Object.values(NoteTextDirection).find((dir) => dir === rawData.dir) : undefined) ??
+      NoteTextDirection.LTR
+    if (typeof rawData?.tags === 'string') {
+      this.tags = rawData?.tags?.split(',').map((entry) => entry.trim()) ?? []
+      this.deprecatedTagsSyntax = true
+    } else if (typeof rawData?.tags === 'object') {
+      this.tags = rawData?.tags?.filter((tag) => tag !== null) ?? []
+      this.deprecatedTagsSyntax = false
+    } else {
+      this.tags = []
+      this.deprecatedTagsSyntax = false
+    }
+    this.opengraph = rawData?.opengraph
+      ? new Map<string, string>(Object.entries(rawData.opengraph))
+      : new Map<string, string>()
+  }
+
+  /**
+   * Creates a new frontmatter metadata instance based on a raw yaml string.
+   * @param rawYaml The frontmatter content in yaml format.
+   * @throws Error when the content string is invalid yaml.
+   * @return Frontmatter metadata instance containing the parsed properties from the yaml content.
+   */
+  static createFromYaml(rawYaml: string): NoteFrontmatter {
+    const rawNoteFrontmatter = load(rawYaml) as RawNoteFrontmatter
+    return new NoteFrontmatter(rawNoteFrontmatter)
+  }
+}

src/components/common/note-frontmatter/types.ts

@@ -4,7 +4,23 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-// import { RevealOptions } from 'reveal.js'
+export type FrontmatterExtractionResult = PresentFrontmatterExtractionResult | NonPresentFrontmatterExtractionResult
+
+export interface RendererFrontmatterInfo {
+  offsetLines: number
+  frontmatterInvalid: boolean
+  deprecatedSyntax: boolean
+}
+
+export interface PresentFrontmatterExtractionResult {
+  frontmatterPresent: true
+  rawFrontmatterText: string
+  frontmatterLines: number
+}
+
+interface NonPresentFrontmatterExtractionResult {
+  frontmatterPresent: false
+}
 
 export interface RawNoteFrontmatter {
   title: string | undefined
@@ -235,52 +251,3 @@ export enum NoteTextDirection {
   LTR = 'ltr',
   RTL = 'rtl'
 }
-
-export class NoteFrontmatter {
-  title: string
-  description: string
-  tags: string[]
-  deprecatedTagsSyntax: boolean
-  robots: string
-  lang: typeof ISO6391[number]
-  dir: NoteTextDirection
-  breaks: boolean
-  GA: string
-  disqus: string
-  type: NoteType
-  // slideOptions: RevealOptions
-  opengraph: Map<string, string>
-
-  constructor(rawData: RawNoteFrontmatter) {
-    this.title = rawData.title ?? ''
-    this.description = rawData.description ?? ''
-    this.robots = rawData.robots ?? ''
-    this.breaks = rawData.breaks ?? true
-    this.GA = rawData.GA ?? ''
-    this.disqus = rawData.disqus ?? ''
-    this.lang = (rawData.lang ? ISO6391.find((lang) => lang === rawData.lang) : undefined) ?? 'en'
-    this.type =
-      (rawData.type ? Object.values(NoteType).find((type) => type === rawData.type) : undefined) ?? NoteType.DOCUMENT
-    this.dir =
-      (rawData.dir ? Object.values(NoteTextDirection).find((dir) => dir === rawData.dir) : undefined) ??
-      NoteTextDirection.LTR
-
-    /* this.slideOptions = (rawData?.slideOptions as RevealOptions) ?? {
-     transition: 'none',
-     theme: 'white'
-     } */
-    if (typeof rawData?.tags === 'string') {
-      this.tags = rawData?.tags?.split(',').map((entry) => entry.trim()) ?? []
-      this.deprecatedTagsSyntax = true
-    } else if (typeof rawData?.tags === 'object') {
-      this.tags = rawData?.tags?.filter((tag) => tag !== null) ?? []
-      this.deprecatedTagsSyntax = false
-    } else {
-      this.tags = []
-      this.deprecatedTagsSyntax = false
-    }
-    this.opengraph = rawData?.opengraph
-      ? new Map<string, string>(Object.entries(rawData.opengraph))
-      : new Map<string, string>()
-  }
-}

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

@@ -10,7 +10,7 @@ import { useParams } from 'react-router'
 import { useApplyDarkMode } from '../../hooks/common/use-apply-dark-mode'
 import { useDocumentTitleWithNoteTitle } from '../../hooks/common/use-document-title-with-note-title'
 import { useNoteMarkdownContent } from '../../hooks/common/use-note-markdown-content'
-import { setNoteFrontmatter, updateNoteTitleByFirstHeading } from '../../redux/note-details/methods'
+import { updateNoteTitleByFirstHeading } from '../../redux/note-details/methods'
 import { MotdBanner } from '../common/motd-banner/motd-banner'
 import { ShowIf } from '../common/show-if/show-if'
 import { AppBar, AppBarMode } from '../editor-page/app-bar/app-bar'
@@ -32,7 +32,6 @@ export const DocumentReadOnlyPage: React.FC = () => {
   useDocumentTitleWithNoteTitle()
 
   const onFirstHeadingChange = useCallback(updateNoteTitleByFirstHeading, [])
-  const onFrontmatterChange = useCallback(setNoteFrontmatter, [])
   const [error, loading] = useLoadNoteFromServer()
   const markdownContent = useNoteMarkdownContent()
   const noteDetails = useApplicationState((state) => state.noteDetails)
@@ -60,7 +59,6 @@ export const DocumentReadOnlyPage: React.FC = () => {
             frameClasses={'flex-fill h-100 w-100'}
             markdownContent={markdownContent}
             onFirstHeadingChange={onFirstHeadingChange}
-            onFrontmatterChange={onFrontmatterChange}
             rendererType={RendererType.DOCUMENT}
           />
         </ShowIf>

src/components/editor-page/app-bar/app-bar.tsx

@@ -14,7 +14,7 @@ import { EditorViewMode } from './editor-view-mode'
 import { HelpButton } from './help-button/help-button'
 import { NavbarBranding } from './navbar-branding'
 import { SyncScrollButtons } from './sync-scroll-buttons/sync-scroll-buttons'
-import { NoteType } from '../note-frontmatter/note-frontmatter'
+import { NoteType } from '../../common/note-frontmatter/types'
 import { SlideModeButton } from './slide-mode-button'
 import { ReadOnlyModeButton } from './read-only-mode-button'
 import { NewNoteButton } from './new-note-button'

src/components/editor-page/document-bar/share/share-modal.tsx

@@ -13,7 +13,7 @@ import { CopyableField } from '../../../common/copyable/copyable-field/copyable-
 import { CommonModal } from '../../../common/modals/common-modal'
 import { ShowIf } from '../../../common/show-if/show-if'
 import { EditorPagePathParams } from '../../editor-page'
-import { NoteType } from '../../note-frontmatter/note-frontmatter'
+import { NoteType } from '../../../common/note-frontmatter/types'
 import { useApplicationState } from '../../../../hooks/common/use-application-state'
 
 export interface ShareModalProps {

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

@@ -11,8 +11,7 @@ import { useDocumentTitleWithNoteTitle } from '../../hooks/common/use-document-t
 import { useNoteMarkdownContent } from '../../hooks/common/use-note-markdown-content'
 import {
   setCheckboxInMarkdownContent,
-  setNoteFrontmatter,
-  setNoteMarkdownContent,
+  setNoteContent,
   updateNoteTitleByFirstHeading
 } from '../../redux/note-details/methods'
 import { MotdBanner } from '../common/motd-banner/motd-banner'
@@ -50,6 +49,7 @@ export const EditorPage: React.FC = () => {
   const markdownContent = useNoteMarkdownContent()
   const scrollSource = useRef<ScrollSource>(ScrollSource.EDITOR)
 
+  const documentContent = useApplicationState((state) => state.noteDetails.documentContent)
   const editorMode: EditorMode = useApplicationState((state) => state.editorConfig.editorMode)
   const editorSyncScroll: boolean = useApplicationState((state) => state.editorConfig.syncScroll)
 
@@ -98,14 +98,14 @@ export const EditorPage: React.FC = () => {
   const leftPane = useMemo(
     () => (
       <EditorPane
-        onContentChange={setNoteMarkdownContent}
-        content={markdownContent}
+        onContentChange={setNoteContent}
+        content={documentContent}
         scrollState={scrollState.editorScrollState}
         onScroll={onEditorScroll}
         onMakeScrollSource={setEditorToScrollSource}
       />
     ),
-    [markdownContent, onEditorScroll, scrollState.editorScrollState, setEditorToScrollSource]
+    [documentContent, onEditorScroll, scrollState.editorScrollState, setEditorToScrollSource]
   )
 
   const rightPane = useMemo(
@@ -116,7 +116,6 @@ export const EditorPage: React.FC = () => {
         onMakeScrollSource={setRendererToScrollSource}
         onFirstHeadingChange={updateNoteTitleByFirstHeading}
         onTaskCheckedChange={setCheckboxInMarkdownContent}
-        onFrontmatterChange={setNoteFrontmatter}
         onScroll={onMarkdownRendererScroll}
         scrollState={scrollState.rendererScrollState}
         rendererType={RendererType.DOCUMENT}

src/components/editor-page/note-frontmatter/note-frontmatter.test.ts

@@ -1,189 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-import yaml from 'js-yaml'
-import MarkdownIt from 'markdown-it'
-import frontmatter from 'markdown-it-front-matter'
-import { NoteFrontmatter, RawNoteFrontmatter } from './note-frontmatter'
-
-describe('yaml frontmatter', () => {
-  const testFrontmatter = (input: string): NoteFrontmatter => {
-    let processedFrontmatter: NoteFrontmatter | undefined = undefined
-    const md = new MarkdownIt('default', {
-      html: true,
-      breaks: true,
-      langPrefix: '',
-      typographer: true
-    })
-    md.use(frontmatter, (rawMeta: string) => {
-      const parsedFrontmatter = yaml.load(rawMeta) as RawNoteFrontmatter | undefined
-      expect(parsedFrontmatter).not.toBe(undefined)
-      if (parsedFrontmatter === undefined) {
-        fail('Parsed frontmatter is undefined')
-      }
-      processedFrontmatter = new NoteFrontmatter(parsedFrontmatter)
-    })
-
-    md.render(input)
-
-    if (processedFrontmatter === undefined) {
-      fail('NoteFrontmatter is undefined')
-    }
-
-    return processedFrontmatter
-  }
-
-  it('should parse "title"', () => {
-    const noteFrontmatter = testFrontmatter(`---
-    title: test
-    ___
-    `)
-
-    expect(noteFrontmatter.title).toEqual('test')
-  })
-
-  it('should parse "robots"', () => {
-    const noteFrontmatter = testFrontmatter(`---
-    robots: index, follow
-    ___
-    `)
-
-    expect(noteFrontmatter.robots).toEqual('index, follow')
-  })
-
-  it('should parse the deprecated tags syntax', () => {
-    const noteFrontmatter = testFrontmatter(`---
-    tags: test123, abc
-    ___
-    `)
-
-    expect(noteFrontmatter.tags).toEqual(['test123', 'abc'])
-    expect(noteFrontmatter.deprecatedTagsSyntax).toEqual(true)
-  })
-
-  it('should parse the tags list syntax', () => {
-    const noteFrontmatter = testFrontmatter(`---
-    tags:
-      - test123
-      - abc
-    ___
-    `)
-
-    expect(noteFrontmatter.tags).toEqual(['test123', 'abc'])
-    expect(noteFrontmatter.deprecatedTagsSyntax).toEqual(false)
-  })
-
-  it('should parse the tag inline-list syntax', () => {
-    const noteFrontmatter = testFrontmatter(`---
-    tags: ['test123', 'abc']
-    ___
-    `)
-
-    expect(noteFrontmatter.tags).toEqual(['test123', 'abc'])
-    expect(noteFrontmatter.deprecatedTagsSyntax).toEqual(false)
-  })
-
-  it('should parse "breaks"', () => {
-    const noteFrontmatter = testFrontmatter(`---
-    breaks: false
-    ___
-    `)
-
-    expect(noteFrontmatter.breaks).toEqual(false)
-  })
-
-  /*
-   it('slideOptions nothing', () => {
-   testFrontmatter(`---
-   slideOptions:
-   ___
-   `,
-   {
-   slideOptions: null
-   },
-   {
-   slideOptions: {
-   theme: 'white',
-   transition: 'none'
-   }
-   })
-   })
-
-   it('slideOptions.theme only', () => {
-   testFrontmatter(`---
-   slideOptions:
-   theme: sky
-   ___
-   `,
-   {
-   slideOptions: {
-   theme: 'sky',
-   transition: undefined
-   }
-   },
-   {
-   slideOptions: {
-   theme: 'sky',
-   transition: 'none'
-   }
-   })
-   })
-
-   it('slideOptions full', () => {
-   testFrontmatter(`---
-   slideOptions:
-   transition: zoom
-   theme: sky
-   ___
-   `,
-   {
-   slideOptions: {
-   theme: 'sky',
-   transition: 'zoom'
-   }
-   },
-   {
-   slideOptions: {
-   theme: 'sky',
-   transition: 'zoom'
-   }
-   })
-   })
-   */
-
-  it('should parse an empty opengraph object', () => {
-    const noteFrontmatter = testFrontmatter(`---
-    opengraph:
-    ___
-    `)
-
-    expect(noteFrontmatter.opengraph).toEqual(new Map<string, string>())
-  })
-
-  it('should parse an opengraph title', () => {
-    const noteFrontmatter = testFrontmatter(`---
-    opengraph:
-      title: Testtitle
-    ___
-    `)
-
-    expect(noteFrontmatter.opengraph.get('title')).toEqual('Testtitle')
-  })
-
-  it('should opengraph values', () => {
-    const noteFrontmatter = testFrontmatter(`---
-    opengraph:
-      title: Testtitle
-      image: https://dummyimage.com/48.png
-      image:type: image/png
-    ___
-    `)
-
-    expect(noteFrontmatter.opengraph.get('title')).toEqual('Testtitle')
-    expect(noteFrontmatter.opengraph.get('image')).toEqual('https://dummyimage.com/48.png')
-    expect(noteFrontmatter.opengraph.get('image:type')).toEqual('image/png')
-  })
-})

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

@@ -25,7 +25,6 @@ export interface RenderIframeProps extends RendererProps {
 export const RenderIframe: React.FC<RenderIframeProps> = ({
   markdownContent,
   onTaskCheckedChange,
-  onFrontmatterChange,
   scrollState,
   onFirstHeadingChange,
   onScroll,
@@ -39,6 +38,7 @@ export const RenderIframe: React.FC<RenderIframeProps> = ({
   const [lightboxDetails, setLightboxDetails] = useState<ImageDetails | undefined>(undefined)
 
   const frameReference = useRef<HTMLIFrameElement>(null)
+  const frontmatterInfo = useApplicationState((state) => state.noteDetails.frontmatterRendererInfo)
   const rendererOrigin = useApplicationState((state) => state.config.iframeCommunication.rendererOrigin)
   const renderPageUrl = `${rendererOrigin}render`
   const resetRendererReady = useCallback(() => setRendererStatus(false), [])
@@ -67,11 +67,6 @@ export const RenderIframe: React.FC<RenderIframeProps> = ({
     return () => iframeCommunicator.onFirstHeadingChange(undefined)
   }, [iframeCommunicator, onFirstHeadingChange])
 
-  useEffect(() => {
-    iframeCommunicator.onFrontmatterChange(onFrontmatterChange)
-    return () => iframeCommunicator.onFrontmatterChange(undefined)
-  }, [iframeCommunicator, onFrontmatterChange])
-
   useEffect(() => {
     iframeCommunicator.onSetScrollState(onScroll)
     return () => iframeCommunicator.onSetScrollState(undefined)
@@ -128,6 +123,12 @@ export const RenderIframe: React.FC<RenderIframeProps> = ({
     }
   }, [iframeCommunicator, markdownContent, rendererReady])
 
+  useEffect(() => {
+    if (rendererReady && frontmatterInfo !== undefined) {
+      iframeCommunicator.sendSetFrontmatterInfo(frontmatterInfo)
+    }
+  }, [iframeCommunicator, rendererReady, frontmatterInfo])
+
   return (
     <Fragment>
       <ShowOnPropChangeImageLightbox details={lightboxDetails} />

src/components/editor-page/renderer-pane/yaml-array-deprecation-alert.tsx

@@ -10,14 +10,13 @@ import { Trans, useTranslation } from 'react-i18next'
 import links from '../../../links.json'
 import { TranslatedExternalLink } from '../../common/links/translated-external-link'
 import { ShowIf } from '../../common/show-if/show-if'
-import { useApplicationState } from '../../../hooks/common/use-application-state'
+import { CommonModalProps } from '../../common/modals/common-modal'
 
-export const YamlArrayDeprecationAlert: React.FC = () => {
+export const YamlArrayDeprecationAlert: React.FC<Partial<CommonModalProps>> = ({ show }) => {
   useTranslation()
-  const yamlDeprecatedTags = useApplicationState((state) => state.noteDetails.frontmatter.deprecatedTagsSyntax)
 
   return (
-    <ShowIf condition={yamlDeprecatedTags}>
+    <ShowIf condition={!!show}>
       <Alert data-cy={'yamlArrayDeprecationAlert'} className={'text-wrap'} variant='warning' dir='auto'>
         <span className={'text-wrap'}>
           <span className={'text-wrap'}>

src/components/editor-page/sidebar/export-markdown-sidebar-entry.tsx

@@ -8,17 +8,17 @@ import React, { useCallback } from 'react'
 import sanitize from 'sanitize-filename'
 import { store } from '../../../redux'
 import { Trans, useTranslation } from 'react-i18next'
-import { useNoteMarkdownContent } from '../../../hooks/common/use-note-markdown-content'
 import { download } from '../../common/download/download'
 import { SidebarButton } from './sidebar-button'
+import { useApplicationState } from '../../../hooks/common/use-application-state'
 
 export const ExportMarkdownSidebarEntry: React.FC = () => {
   const { t } = useTranslation()
-  const markdownContent = useNoteMarkdownContent()
+  const documentContent = useApplicationState((state) => state.noteDetails.documentContent)
   const onClick = useCallback(() => {
     const sanitized = sanitize(store.getState().noteDetails.noteTitle)
-    download(markdownContent, `${sanitized !== '' ? sanitized : t('editor.untitledNote')}.md`, 'text/markdown')
-  }, [markdownContent, t])
+    download(documentContent, `${sanitized !== '' ? sanitized : t('editor.untitledNote')}.md`, 'text/markdown')
+  }, [documentContent, t])
 
   return (
     <SidebarButton data-cy={'menu-export-markdown'} onClick={onClick} icon={'file-text'}>

src/components/editor-page/sidebar/import-markdown-sidebar-entry.tsx

@@ -7,7 +7,7 @@
 import React, { Fragment, useCallback, useRef } from 'react'
 import { Trans, useTranslation } from 'react-i18next'
 import { useNoteMarkdownContent } from '../../../hooks/common/use-note-markdown-content'
-import { setNoteMarkdownContent } from '../../../redux/note-details/methods'
+import { setNoteContent } from '../../../redux/note-details/methods'
 import { SidebarButton } from './sidebar-button'
 import { UploadInput } from './upload-input'
 
@@ -21,7 +21,7 @@ export const ImportMarkdownSidebarEntry: React.FC = () => {
         const fileReader = new FileReader()
         fileReader.addEventListener('load', () => {
           const newContent = fileReader.result as string
-          setNoteMarkdownContent(markdownContent.length === 0 ? newContent : `${markdownContent}\n${newContent}`)
+          setNoteContent(markdownContent.length === 0 ? newContent : `${markdownContent}\n${newContent}`)
         })
         fileReader.addEventListener('loadend', () => {
           resolve()

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

@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import React, { Ref, useCallback, useMemo, useRef, useState } from 'react'
+import React, { Ref, useCallback, useMemo, useRef } from 'react'
 import { DocumentLengthLimitReachedAlert } from './document-length-limit-reached-alert'
 import { useConvertMarkdownToReactDom } from './hooks/use-convert-markdown-to-react-dom'
 import './markdown-renderer.scss'
@@ -12,7 +12,6 @@ import { ComponentReplacer } from './replace-components/ComponentReplacer'
 import { AdditionalMarkdownRendererProps, LineMarkerPosition } from './types'
 import { useComponentReplacers } from './hooks/use-component-replacers'
 import { useTranslation } from 'react-i18next'
-import { NoteFrontmatter, RawNoteFrontmatter } from '../editor-page/note-frontmatter/note-frontmatter'
 import { LineMarkers } from './replace-components/linemarker/line-number-marker'
 import { useCalculateLineMarkerPosition } from './utils/calculate-line-marker-positions'
 import { useExtractFirstHeadline } from './hooks/use-extract-first-headline'
@@ -20,7 +19,6 @@ import { TocAst } from 'markdown-it-toc-done-right'
 import { useOnRefChange } from './hooks/use-on-ref-change'
 import { BasicMarkdownItConfigurator } from './markdown-it-configurator/BasicMarkdownItConfigurator'
 import { ImageClickHandler } from './replace-components/image/image-replacer'
-import { InvalidYamlAlert } from './invalid-yaml-alert'
 import { useTrimmedContent } from './hooks/use-trimmed-content'
 
 export interface BasicMarkdownRendererProps {
@@ -29,79 +27,57 @@ export interface BasicMarkdownRendererProps {
   onAfterRendering?: () => void
   onFirstHeadingChange?: (firstHeading: string | undefined) => void
   onLineMarkerPositionChanged?: (lineMarkerPosition: LineMarkerPosition[]) => void
-  onFrontmatterChange?: (frontmatter: NoteFrontmatter | undefined) => void
   onTaskCheckedChange?: (lineInMarkdown: number, checked: boolean) => void
   onTocChange?: (ast?: TocAst) => void
   baseUrl?: string
   onImageClick?: ImageClickHandler
   outerContainerRef?: Ref<HTMLDivElement>
   useAlternativeBreaks?: boolean
+  frontmatterLineOffset?: number
 }
 
 export const BasicMarkdownRenderer: React.FC<BasicMarkdownRendererProps & AdditionalMarkdownRendererProps> = ({
   className,
   content,
   additionalReplacers,
-  onBeforeRendering,
-  onAfterRendering,
   onFirstHeadingChange,
   onLineMarkerPositionChanged,
-  onFrontmatterChange,
   onTaskCheckedChange,
   onTocChange,
   baseUrl,
   onImageClick,
   outerContainerRef,
-  useAlternativeBreaks
+  useAlternativeBreaks,
+  frontmatterLineOffset
 }) => {
-  const rawMetaRef = useRef<RawNoteFrontmatter>()
   const markdownBodyRef = useRef<HTMLDivElement>(null)
   const currentLineMarkers = useRef<LineMarkers[]>()
   const hasNewYamlError = useRef(false)
   const tocAst = useRef<TocAst>()
-  const [showYamlError, setShowYamlError] = useState(false)
   const [trimmedContent, contentExceedsLimit] = useTrimmedContent(content)
 
   const markdownIt = useMemo(
     () =>
       new BasicMarkdownItConfigurator({
-        useFrontmatter: !!onFrontmatterChange,
         onParseError: (errorState) => (hasNewYamlError.current = errorState),
-        onRawMetaChange: (rawMeta) => (rawMetaRef.current = rawMeta),
         onToc: (toc) => (tocAst.current = toc),
         onLineMarkers:
           onLineMarkerPositionChanged === undefined
             ? undefined
             : (lineMarkers) => (currentLineMarkers.current = lineMarkers),
-        useAlternativeBreaks
+        useAlternativeBreaks,
+        offsetLines: frontmatterLineOffset
       }).buildConfiguredMarkdownIt(),
-    [onFrontmatterChange, onLineMarkerPositionChanged, useAlternativeBreaks]
+    [onLineMarkerPositionChanged, useAlternativeBreaks, frontmatterLineOffset]
   )
 
-  const clearFrontmatter = useCallback(() => {
-    hasNewYamlError.current = false
-    rawMetaRef.current = undefined
-    onBeforeRendering?.()
-  }, [onBeforeRendering])
-
-  const checkYamlErrorState = useCallback(() => {
-    setShowYamlError(hasNewYamlError.current)
-    onAfterRendering?.()
-  }, [onAfterRendering])
-
-  const baseReplacers = useComponentReplacers(onTaskCheckedChange, onImageClick, baseUrl)
+  const baseReplacers = useComponentReplacers(onTaskCheckedChange, onImageClick, baseUrl, frontmatterLineOffset)
   const replacers = useCallback(
     () => baseReplacers().concat(additionalReplacers ? additionalReplacers() : []),
     [additionalReplacers, baseReplacers]
   )
 
-  const markdownReactDom = useConvertMarkdownToReactDom(
-    trimmedContent,
-    markdownIt,
-    replacers,
-    clearFrontmatter,
-    checkYamlErrorState
-  )
+  const markdownReactDom = useConvertMarkdownToReactDom(trimmedContent, markdownIt, replacers)
 
   useTranslation()
   useCalculateLineMarkerPosition(
@@ -112,17 +88,9 @@ export const BasicMarkdownRenderer: React.FC<BasicMarkdownRendererProps & Additi
   )
   useExtractFirstHeadline(markdownBodyRef, content, onFirstHeadingChange)
   useOnRefChange(tocAst, onTocChange)
-  useOnRefChange(rawMetaRef, (newValue) => {
-    if (!newValue) {
-      onFrontmatterChange?.(undefined)
-    } else {
-      onFrontmatterChange?.(new NoteFrontmatter(newValue))
-    }
-  })
 
   return (
     <div ref={outerContainerRef} className={'position-relative'}>
-      <InvalidYamlAlert show={showYamlError} />
       <DocumentLengthLimitReachedAlert show={contentExceedsLimit} />
       <div
         ref={markdownBodyRef}

src/components/markdown-renderer/hooks/use-component-replacers.ts

@@ -32,13 +32,15 @@ import { YoutubeReplacer } from '../replace-components/youtube/youtube-replacer'
  * @param onTaskCheckedChange A callback that gets executed if a task checkbox gets clicked
  * @param onImageClick A callback that should be executed if an image gets clicked
  * @param baseUrl The base url for relative links
+ * @param frontmatterLinesToSkip The number of lines of the frontmatter part to add this as offset to line-numbers.
  *
  * @return the created list
  */
 export const useComponentReplacers = (
   onTaskCheckedChange?: TaskCheckedChangeHandler,
   onImageClick?: ImageClickHandler,
-  baseUrl?: string
+  baseUrl?: string,
+  frontmatterLinesToSkip?: number
 ): (() => ComponentReplacer[]) =>
   useCallback(
     () => [
@@ -59,8 +61,8 @@ export const useComponentReplacers = (
       new HighlightedCodeReplacer(),
       new ColoredBlockquoteReplacer(),
       new KatexReplacer(),
-      new TaskListReplacer(onTaskCheckedChange),
+      new TaskListReplacer(onTaskCheckedChange, frontmatterLinesToSkip),
       new LinkReplacer(baseUrl)
     ],
-    [onImageClick, onTaskCheckedChange, baseUrl]
+    [onImageClick, onTaskCheckedChange, baseUrl, frontmatterLinesToSkip]
   )

src/components/markdown-renderer/markdown-it-configurator/BasicMarkdownItConfigurator.tsx

@@ -19,7 +19,6 @@ import { MarkdownItParserDebugger } from '../markdown-it-plugins/parser-debugger
 import { spoilerContainer } from '../markdown-it-plugins/spoiler-container'
 import { tasksLists } from '../markdown-it-plugins/tasks-lists'
 import { twitterEmojis } from '../markdown-it-plugins/twitter-emojis'
-import { RawNoteFrontmatter } from '../../editor-page/note-frontmatter/note-frontmatter'
 import { TocAst } from 'markdown-it-toc-done-right'
 import { LineMarkers, lineNumberMarker } from '../replace-components/linemarker/line-number-marker'
 import { plantumlWithError } from '../markdown-it-plugins/plantuml'
@@ -36,15 +35,13 @@ import { highlightedCode } from '../markdown-it-plugins/highlighted-code'
 import { quoteExtraColor } from '../markdown-it-plugins/quote-extra-color'
 import { quoteExtra } from '../markdown-it-plugins/quote-extra'
 import { documentTableOfContents } from '../markdown-it-plugins/document-table-of-contents'
-import { frontmatterExtract } from '../markdown-it-plugins/frontmatter'
 
 export interface ConfiguratorDetails {
-  useFrontmatter: boolean
   onParseError: (error: boolean) => void
-  onRawMetaChange: (rawMeta: RawNoteFrontmatter) => void
   onToc: (toc: TocAst) => void
   onLineMarkers?: (lineMarkers: LineMarkers[]) => void
   useAlternativeBreaks?: boolean
+  offsetLines?: number
 }
 
 export class BasicMarkdownItConfigurator<T extends ConfiguratorDetails> {
@@ -105,17 +102,8 @@ export class BasicMarkdownItConfigurator<T extends ConfiguratorDetails> {
       spoilerContainer
     )
 
-    if (this.options.useFrontmatter) {
-      this.configurations.push(
-        frontmatterExtract({
-          onParseError: this.options.onParseError,
-          onRawMetaChange: this.options.onRawMetaChange
-        })
-      )
-    }
-
     if (this.options.onLineMarkers) {
-      this.configurations.push(lineNumberMarker(this.options.onLineMarkers))
+      this.configurations.push(lineNumberMarker(this.options.onLineMarkers, this.options.offsetLines ?? 0))
     }
 
     this.postConfigurations.push(linkifyExtra, MarkdownItParserDebugger)

src/components/markdown-renderer/markdown-it-plugins/frontmatter.ts

@@ -1,30 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-import yaml from 'js-yaml'
-import MarkdownIt from 'markdown-it'
-import frontmatter from 'markdown-it-front-matter'
-import { RawNoteFrontmatter } from '../../editor-page/note-frontmatter/note-frontmatter'
-
-interface FrontmatterPluginOptions {
-  onParseError: (error: boolean) => void
-  onRawMetaChange: (rawMeta: RawNoteFrontmatter) => void
-}
-
-export const frontmatterExtract: (options: FrontmatterPluginOptions) => MarkdownIt.PluginSimple =
-  (options) => (markdownIt) => {
-    frontmatter(markdownIt, (rawMeta: string) => {
-      try {
-        const meta: RawNoteFrontmatter = yaml.load(rawMeta) as RawNoteFrontmatter
-        options.onParseError(false)
-        options.onRawMetaChange(meta)
-      } catch (e) {
-        console.error(e)
-        options.onParseError(true)
-        options.onRawMetaChange({} as RawNoteFrontmatter)
-      }
-    })
-  }

src/components/markdown-renderer/replace-components/linemarker/line-number-marker.ts

@@ -18,12 +18,13 @@ export type LineNumberMarkerOptions = (lineMarkers: LineMarkers[]) => void
  * This plugin adds markers to the dom, that are used to map line numbers to dom elements.
  * It also provides a list of line numbers for the top level dom elements.
  */
-export const lineNumberMarker: (options: LineNumberMarkerOptions) => MarkdownIt.PluginSimple =
-  (options) => (md: MarkdownIt) => {
+export const lineNumberMarker: (options: LineNumberMarkerOptions, offsetLines: number) => MarkdownIt.PluginSimple =
+  (options, offsetLines = 0) =>
+  (md: MarkdownIt) => {
     // add app_linemarker token before each opening or self-closing level-0 tag
     md.core.ruler.push('line_number_marker', (state) => {
       const lineMarkers: LineMarkers[] = []
-      tagTokens(state.tokens, lineMarkers)
+      tagTokens(state.tokens, lineMarkers, offsetLines)
       if (options) {
         options(lineMarkers)
       }
@@ -56,7 +57,7 @@ export const lineNumberMarker: (options: LineNumberMarkerOptions) => MarkdownIt.
       tokens.splice(tokenPosition, 0, startToken)
     }
 
-    const tagTokens = (tokens: Token[], lineMarkers: LineMarkers[]) => {
+    const tagTokens = (tokens: Token[], lineMarkers: LineMarkers[], offsetLines: number) => {
       for (let tokenPosition = 0; tokenPosition < tokens.length; tokenPosition++) {
         const token = tokens[tokenPosition]
         if (token.hidden) {
@@ -71,14 +72,14 @@ export const lineNumberMarker: (options: LineNumberMarkerOptions) => MarkdownIt.
         const endLineNumber = token.map[1] + 1
 
         if (token.level === 0) {
-          lineMarkers.push({ startLine: startLineNumber, endLine: endLineNumber })
+          lineMarkers.push({ startLine: startLineNumber + offsetLines, endLine: endLineNumber + offsetLines })
         }
 
         insertNewLineMarker(startLineNumber, endLineNumber, tokenPosition, token.level, tokens)
         tokenPosition += 1
 
         if (token.children) {
-          tagTokens(token.children, lineMarkers)
+          tagTokens(token.children, lineMarkers, offsetLines)
         }
       }
     }

src/components/markdown-renderer/replace-components/task-list/task-list-replacer.tsx

@@ -15,16 +15,18 @@ export type TaskCheckedChangeHandler = (lineInMarkdown: number, checked: boolean
  */
 export class TaskListReplacer extends ComponentReplacer {
   onTaskCheckedChange?: (lineInMarkdown: number, checked: boolean) => void
+  private readonly frontmatterLinesOffset
 
-  constructor(onTaskCheckedChange?: TaskCheckedChangeHandler) {
+  constructor(onTaskCheckedChange?: TaskCheckedChangeHandler, frontmatterLinesOffset?: number) {
     super()
     this.onTaskCheckedChange = onTaskCheckedChange
+    this.frontmatterLinesOffset = frontmatterLinesOffset ?? 0
   }
 
   handleCheckboxChange = (event: React.ChangeEvent<HTMLInputElement>): void => {
     const lineNum = Number(event.currentTarget.dataset.line)
     if (this.onTaskCheckedChange) {
-      this.onTaskCheckedChange(lineNum, event.currentTarget.checked)
+      this.onTaskCheckedChange(lineNum + this.frontmatterLinesOffset, event.currentTarget.checked)
     }
   }
 

src/components/render-page/iframe-editor-to-renderer-communicator.ts

@@ -3,8 +3,6 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-
-import { NoteFrontmatter } from '../editor-page/note-frontmatter/note-frontmatter'
 import { ScrollState } from '../editor-page/synced-scroll/scroll-props'
 import { IframeCommunicator } from './iframe-communicator'
 import {
@@ -14,6 +12,7 @@ import {
   RendererToEditorIframeMessage,
   RenderIframeMessageType
 } from './rendering-message'
+import { RendererFrontmatterInfo } from '../common/note-frontmatter/types'
 
 export class IframeEditorToRendererCommunicator extends IframeCommunicator<
   EditorToRendererIframeMessage,
@@ -22,7 +21,6 @@ export class IframeEditorToRendererCommunicator extends IframeCommunicator<
   private onSetScrollSourceToRendererHandler?: () => void
   private onTaskCheckboxChangeHandler?: (lineInMarkdown: number, checked: boolean) => void
   private onFirstHeadingChangeHandler?: (heading?: string) => void
-  private onFrontmatterChangeHandler?: (frontmatter?: NoteFrontmatter) => void
   private onSetScrollStateHandler?: (scrollState: ScrollState) => void
   private onRendererReadyHandler?: () => void
   private onImageClickedHandler?: (details: ImageDetails) => void
@@ -33,10 +31,6 @@ export class IframeEditorToRendererCommunicator extends IframeCommunicator<
     this.onHeightChangeHandler = handler
   }
 
-  public onFrontmatterChange(handler?: (frontmatter?: NoteFrontmatter) => void): void {
-    this.onFrontmatterChangeHandler = handler
-  }
-
   public onImageClicked(handler?: (details: ImageDetails) => void): void {
     this.onImageClickedHandler = handler
   }
@@ -102,6 +96,13 @@ export class IframeEditorToRendererCommunicator extends IframeCommunicator<
     })
   }
 
+  public sendSetFrontmatterInfo(frontmatterInfo: RendererFrontmatterInfo): void {
+    this.sendMessageToOtherSide({
+      type: RenderIframeMessageType.SET_FRONTMATTER_INFO,
+      frontmatterInfo: frontmatterInfo
+    })
+  }
+
   protected handleEvent(event: MessageEvent<RendererToEditorIframeMessage>): boolean | undefined {
     const renderMessage = event.data
     switch (renderMessage.type) {
@@ -121,9 +122,6 @@ export class IframeEditorToRendererCommunicator extends IframeCommunicator<
       case RenderIframeMessageType.ON_TASK_CHECKBOX_CHANGE:
         this.onTaskCheckboxChangeHandler?.(renderMessage.lineInMarkdown, renderMessage.checked)
         return false
-      case RenderIframeMessageType.ON_SET_FRONTMATTER:
-        this.onFrontmatterChangeHandler?.(renderMessage.frontmatter)
-        return false
       case RenderIframeMessageType.IMAGE_CLICKED:
         this.onImageClickedHandler?.(renderMessage.details)
         return false

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

@@ -8,18 +8,22 @@ import React, { useCallback, useEffect, useState } from 'react'
 import { ScrollState } from '../editor-page/synced-scroll/scroll-props'
 import { BaseConfiguration, RendererType } from './rendering-message'
 import { setDarkMode } from '../../redux/dark-mode/methods'
-import { NoteFrontmatter } from '../editor-page/note-frontmatter/note-frontmatter'
-import { setNoteFrontmatter } from '../../redux/note-details/methods'
 import { ImageClickHandler } from '../markdown-renderer/replace-components/image/image-replacer'
 import { useImageClickHandler } from './hooks/use-image-click-handler'
 import { MarkdownDocument } from './markdown-document'
 import { useIFrameRendererToEditorCommunicator } from '../editor-page/render-context/iframe-renderer-to-editor-communicator-context-provider'
 import { countWords } from './word-counter'
+import { RendererFrontmatterInfo } from '../common/note-frontmatter/types'
 
 export const IframeMarkdownRenderer: React.FC = () => {
   const [markdownContent, setMarkdownContent] = useState('')
   const [scrollState, setScrollState] = useState<ScrollState>({ firstLineInView: 1, scrolledPercentage: 0 })
   const [baseConfiguration, setBaseConfiguration] = useState<BaseConfiguration | undefined>(undefined)
+  const [frontmatterInfo, setFrontmatterInfo] = useState<RendererFrontmatterInfo>({
+    offsetLines: 0,
+    frontmatterInvalid: false,
+    deprecatedSyntax: false
+  })
 
   const iframeCommunicator = useIFrameRendererToEditorCommunicator()
 
@@ -37,6 +41,7 @@ export const IframeMarkdownRenderer: React.FC = () => {
   useEffect(() => iframeCommunicator.onSetMarkdownContent(setMarkdownContent), [iframeCommunicator])
   useEffect(() => iframeCommunicator.onSetDarkMode(setDarkMode), [iframeCommunicator])
   useEffect(() => iframeCommunicator.onSetScrollState(setScrollState), [iframeCommunicator, scrollState])
+  useEffect(() => iframeCommunicator.onSetFrontmatterInfo(setFrontmatterInfo), [iframeCommunicator, setFrontmatterInfo])
   useEffect(
     () => iframeCommunicator.onGetWordCount(countWordsInRenderedDocument),
     [iframeCommunicator, countWordsInRenderedDocument]
@@ -60,14 +65,6 @@ export const IframeMarkdownRenderer: React.FC = () => {
     iframeCommunicator.sendSetScrollSourceToRenderer()
   }, [iframeCommunicator])
 
-  const onFrontmatterChange = useCallback(
-    (frontmatter?: NoteFrontmatter) => {
-      setNoteFrontmatter(frontmatter)
-      iframeCommunicator.sendSetFrontmatter(frontmatter)
-    },
-    [iframeCommunicator]
-  )
-
   const onScroll = useCallback(
     (scrollState: ScrollState) => {
       iframeCommunicator.sendSetScrollState(scrollState)
@@ -97,11 +94,11 @@ export const IframeMarkdownRenderer: React.FC = () => {
           onTaskCheckedChange={onTaskCheckedChange}
           onFirstHeadingChange={onFirstHeadingChange}
           onMakeScrollSource={onMakeScrollSource}
-          onFrontmatterChange={onFrontmatterChange}
           scrollState={scrollState}
           onScroll={onScroll}
           baseUrl={baseConfiguration.baseUrl}
           onImageClick={onImageClick}
+          frontmatterInfo={frontmatterInfo}
         />
       )
     case RendererType.INTRO:

src/components/render-page/iframe-renderer-to-editor-communicator.ts

@@ -4,7 +4,6 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { NoteFrontmatter } from '../editor-page/note-frontmatter/note-frontmatter'
 import { ScrollState } from '../editor-page/synced-scroll/scroll-props'
 import { IframeCommunicator } from './iframe-communicator'
 import {
@@ -14,6 +13,7 @@ import {
   RendererToEditorIframeMessage,
   RenderIframeMessageType
 } from './rendering-message'
+import { RendererFrontmatterInfo } from '../common/note-frontmatter/types'
 
 export class IframeRendererToEditorCommunicator extends IframeCommunicator<
   RendererToEditorIframeMessage,
@@ -24,6 +24,7 @@ export class IframeRendererToEditorCommunicator extends IframeCommunicator<
   private onSetScrollStateHandler?: (scrollState: ScrollState) => void
   private onSetBaseConfigurationHandler?: (baseConfiguration: BaseConfiguration) => void
   private onGetWordCountHandler?: () => void
+  private onSetFrontmatterInfoHandler?: (frontmatterInfo: RendererFrontmatterInfo) => void
 
   public onSetBaseConfiguration(handler?: (baseConfiguration: BaseConfiguration) => void): void {
     this.onSetBaseConfigurationHandler = handler
@@ -45,6 +46,10 @@ export class IframeRendererToEditorCommunicator extends IframeCommunicator<
     this.onGetWordCountHandler = handler
   }
 
+  public onSetFrontmatterInfo(handler?: (frontmatterInfo: RendererFrontmatterInfo) => void): void {
+    this.onSetFrontmatterInfoHandler = handler
+  }
+
   public sendRendererReady(): void {
     this.enableCommunication()
     this.sendMessageToOtherSide({
@@ -73,13 +78,6 @@ export class IframeRendererToEditorCommunicator extends IframeCommunicator<
     })
   }
 
-  public sendSetFrontmatter(frontmatter: NoteFrontmatter | undefined): void {
-    this.sendMessageToOtherSide({
-      type: RenderIframeMessageType.ON_SET_FRONTMATTER,
-      frontmatter: frontmatter
-    })
-  }
-
   public sendSetScrollState(scrollState: ScrollState): void {
     this.sendMessageToOtherSide({
       type: RenderIframeMessageType.SET_SCROLL_STATE,
@@ -126,6 +124,9 @@ export class IframeRendererToEditorCommunicator extends IframeCommunicator<
       case RenderIframeMessageType.GET_WORD_COUNT:
         this.onGetWordCountHandler?.()
         return false
+      case RenderIframeMessageType.SET_FRONTMATTER_INFO:
+        this.onSetFrontmatterInfoHandler?.(renderMessage.frontmatterInfo)
+        return false
     }
   }
 }

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

@@ -7,7 +7,6 @@
 import { TocAst } from 'markdown-it-toc-done-right'
 import React, { MutableRefObject, useEffect, useMemo, useRef, useState } from 'react'
 import useResizeObserver from 'use-resize-observer'
-import { NoteFrontmatter } from '../editor-page/note-frontmatter/note-frontmatter'
 import { YamlArrayDeprecationAlert } from '../editor-page/renderer-pane/yaml-array-deprecation-alert'
 import { useSyncedScrolling } from '../editor-page/synced-scroll/hooks/use-synced-scrolling'
 import { ScrollProps } from '../editor-page/synced-scroll/scroll-props'
@@ -17,10 +16,11 @@ import './markdown-document.scss'
 import { WidthBasedTableOfContents } from './width-based-table-of-contents'
 import { ShowIf } from '../common/show-if/show-if'
 import { useApplicationState } from '../../hooks/common/use-application-state'
+import { RendererFrontmatterInfo } from '../common/note-frontmatter/types'
+import { InvalidYamlAlert } from '../markdown-renderer/invalid-yaml-alert'
 
 export interface RendererProps extends ScrollProps {
   onFirstHeadingChange?: (firstHeading: string | undefined) => void
-  onFrontmatterChange?: (frontmatter: NoteFrontmatter | undefined) => void
   onTaskCheckedChange?: (lineInMarkdown: number, checked: boolean) => void
   documentRenderPaneRef?: MutableRefObject<HTMLDivElement | null>
   markdownContent: string
@@ -33,13 +33,13 @@ export interface MarkdownDocumentProps extends RendererProps {
   additionalRendererClasses?: string
   disableToc?: boolean
   baseUrl: string
+  frontmatterInfo?: RendererFrontmatterInfo
 }
 
 export const MarkdownDocument: React.FC<MarkdownDocumentProps> = ({
   additionalOuterContainerClasses,
   additionalRendererClasses,
   onFirstHeadingChange,
-  onFrontmatterChange,
   onMakeScrollSource,
   onTaskCheckedChange,
   baseUrl,
@@ -48,7 +48,8 @@ export const MarkdownDocument: React.FC<MarkdownDocumentProps> = ({
   onScroll,
   scrollState,
   onHeightChange,
-  disableToc
+  disableToc,
+  frontmatterInfo
 }) => {
   const rendererRef = useRef<HTMLDivElement | null>(null)
   const rendererSize = useResizeObserver({ ref: rendererRef.current })
@@ -85,19 +86,20 @@ export const MarkdownDocument: React.FC<MarkdownDocumentProps> = ({
       onMouseEnter={onMakeScrollSource}>
       <div className={'markdown-document-side'} />
       <div className={'markdown-document-content'}>
-        <YamlArrayDeprecationAlert />
+        <InvalidYamlAlert show={!!frontmatterInfo?.frontmatterInvalid} />
+        <YamlArrayDeprecationAlert show={!!frontmatterInfo?.deprecatedSyntax} />
         <BasicMarkdownRenderer
           outerContainerRef={rendererRef}
           className={`mb-3 ${additionalRendererClasses ?? ''}`}
           content={markdownContent}
           onFirstHeadingChange={onFirstHeadingChange}
           onLineMarkerPositionChanged={onLineMarkerPositionChanged}
-          onFrontmatterChange={onFrontmatterChange}
           onTaskCheckedChange={onTaskCheckedChange}
           onTocChange={setTocAst}
           baseUrl={baseUrl}
           onImageClick={onImageClick}
           useAlternativeBreaks={useAlternativeBreaks}
+          frontmatterLineOffset={frontmatterInfo?.offsetLines}
         />
       </div>
       <div className={'markdown-document-side pt-4'}>

src/components/render-page/rendering-message.ts

@@ -3,8 +3,8 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import { NoteFrontmatter } from '../editor-page/note-frontmatter/note-frontmatter'
 import { ScrollState } from '../editor-page/synced-scroll/scroll-props'
+import { RendererFrontmatterInfo } from '../common/note-frontmatter/types'
 
 export enum RenderIframeMessageType {
   SET_MARKDOWN_CONTENT = 'SET_MARKDOWN_CONTENT',
@@ -14,12 +14,12 @@ export enum RenderIframeMessageType {
   ON_FIRST_HEADING_CHANGE = 'ON_FIRST_HEADING_CHANGE',
   SET_SCROLL_SOURCE_TO_RENDERER = 'SET_SCROLL_SOURCE_TO_RENDERER',
   SET_SCROLL_STATE = 'SET_SCROLL_STATE',
-  ON_SET_FRONTMATTER = 'ON_SET_FRONTMATTER',
   IMAGE_CLICKED = 'IMAGE_CLICKED',
   ON_HEIGHT_CHANGE = 'ON_HEIGHT_CHANGE',
   SET_BASE_CONFIGURATION = 'SET_BASE_CONFIGURATION',
   GET_WORD_COUNT = 'GET_WORD_COUNT',
-  ON_WORD_COUNT_CALCULATED = 'ON_WORD_COUNT_CALCULATED'
+  ON_WORD_COUNT_CALCULATED = 'ON_WORD_COUNT_CALCULATED',
+  SET_FRONTMATTER_INFO = 'SET_FRONTMATTER_INFO'
 }
 
 export interface RendererToEditorSimpleMessage {
@@ -72,9 +72,9 @@ export interface OnFirstHeadingChangeMessage {
   firstHeading: string | undefined
 }
 
-export interface OnFrontmatterChangeMessage {
-  type: RenderIframeMessageType.ON_SET_FRONTMATTER
-  frontmatter: NoteFrontmatter | undefined
+export interface SetFrontmatterInfoMessage {
+  type: RenderIframeMessageType.SET_FRONTMATTER_INFO
+  frontmatterInfo: RendererFrontmatterInfo
 }
 
 export interface OnHeightChangeMessage {
@@ -93,12 +93,12 @@ export type EditorToRendererIframeMessage =
   | SetScrollStateMessage
   | SetBaseUrlMessage
   | GetWordCountMessage
+  | SetFrontmatterInfoMessage
 
 export type RendererToEditorIframeMessage =
   | RendererToEditorSimpleMessage
   | OnFirstHeadingChangeMessage
   | OnTaskCheckboxChangeMessage
-  | OnFrontmatterChangeMessage
   | SetScrollStateMessage
   | ImageClickedMessage
   | OnHeightChangeMessage

src/redux/index.ts

@@ -15,7 +15,7 @@ import { DarkModeConfigReducer } from './dark-mode/reducers'
 import { DarkModeConfig } from './dark-mode/types'
 import { EditorConfigReducer } from './editor/reducers'
 import { EditorConfig } from './editor/types'
-import { NoteDetailsReducer } from './note-details/reducers'
+import { NoteDetailsReducer } from './note-details/reducer'
 import { NoteDetails } from './note-details/types'
 import { UserReducer } from './user/reducers'
 import { OptionalUserState } from './user/types'

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

@@ -0,0 +1,45 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { NoteDetails } from './types'
+import { DateTime } from 'luxon'
+import { NoteTextDirection, NoteType } from '../../components/common/note-frontmatter/types'
+
+export const initialState: NoteDetails = {
+  documentContent: '',
+  markdownContent: '',
+  rawFrontmatter: '',
+  frontmatterRendererInfo: {
+    frontmatterInvalid: false,
+    deprecatedSyntax: false,
+    offsetLines: 0
+  },
+  id: '',
+  createTime: DateTime.fromSeconds(0),
+  lastChange: {
+    timestamp: DateTime.fromSeconds(0),
+    userName: ''
+  },
+  alias: '',
+  viewCount: 0,
+  authorship: [],
+  noteTitle: '',
+  firstHeading: '',
+  frontmatter: {
+    title: '',
+    description: '',
+    tags: [],
+    deprecatedTagsSyntax: false,
+    robots: '',
+    lang: 'en',
+    dir: NoteTextDirection.LTR,
+    breaks: true,
+    GA: '',
+    disqus: '',
+    type: NoteType.DOCUMENT,
+    opengraph: new Map<string, string>()
+  }
+}

src/redux/note-details/methods.ts

@@ -6,31 +6,40 @@
 
 import { store } from '..'
 import { NoteDto } from '../../api/notes/types'
-import { NoteFrontmatter } from '../../components/editor-page/note-frontmatter/note-frontmatter'
-import { initialState } from './reducers'
 import {
   NoteDetailsActionType,
-  SetCheckboxInMarkdownContentAction,
-  SetNoteDetailsAction,
   SetNoteDetailsFromServerAction,
-  SetNoteFrontmatterFromRenderingAction,
-  UpdateNoteTitleByFirstHeadingAction
+  SetNoteDocumentContentAction,
+  UpdateNoteTitleByFirstHeadingAction,
+  UpdateTaskListCheckboxAction
 } from './types'
 
-export const setNoteMarkdownContent = (content: string): void => {
+/**
+ * Sets the content of the current note, extracts and parses the frontmatter and extracts the markdown content part.
+ * @param content The note content as it is written inside the editor pane.
+ */
+export const setNoteContent = (content: string): void => {
   store.dispatch({
     type: NoteDetailsActionType.SET_DOCUMENT_CONTENT,
-    content
-  } as SetNoteDetailsAction)
+    content: content
+  } as SetNoteDocumentContentAction)
 }
 
+/**
+ * Sets the note metadata for the current note from an API response DTO to the redux.
+ * @param apiResponse The NoteDTO received from the API to store into redux.
+ */
 export const setNoteDataFromServer = (apiResponse: NoteDto): void => {
   store.dispatch({
     type: NoteDetailsActionType.SET_NOTE_DATA_FROM_SERVER,
-    note: apiResponse
+    dto: apiResponse
   } as SetNoteDetailsFromServerAction)
 }
 
+/**
+ * Updates the note title in the redux by the first heading found in the markdown content.
+ * @param firstHeading The content of the first heading found in the markdown content.
+ */
 export const updateNoteTitleByFirstHeading = (firstHeading?: string): void => {
   store.dispatch({
     type: NoteDetailsActionType.UPDATE_NOTE_TITLE_BY_FIRST_HEADING,
@@ -38,20 +47,15 @@ export const updateNoteTitleByFirstHeading = (firstHeading?: string): void => {
   } as UpdateNoteTitleByFirstHeadingAction)
 }
 
-export const setNoteFrontmatter = (frontmatter: NoteFrontmatter | undefined): void => {
-  if (!frontmatter) {
-    frontmatter = initialState.frontmatter
-  }
+/**
+ * Changes a checkbox state in the note document content. Triggered when a checkbox in the rendering is clicked.
+ * @param lineInDocumentContent The line in the document content to change.
+ * @param checked true if the checkbox is checked, false otherwise.
+ */
+export const setCheckboxInMarkdownContent = (lineInDocumentContent: number, checked: boolean): void => {
   store.dispatch({
-    type: NoteDetailsActionType.SET_NOTE_FRONTMATTER,
-    frontmatter: frontmatter
-  } as SetNoteFrontmatterFromRenderingAction)
-}
-
-export const setCheckboxInMarkdownContent = (lineInMarkdown: number, checked: boolean): void => {
-  store.dispatch({
-    type: NoteDetailsActionType.SET_CHECKBOX_IN_MARKDOWN_CONTENT,
-    checked: checked,
-    lineInMarkdown: lineInMarkdown
-  } as SetCheckboxInMarkdownContentAction)
+    type: NoteDetailsActionType.UPDATE_TASK_LIST_CHECKBOX,
+    checkboxChecked: checked,
+    changedLine: lineInDocumentContent
+  } as UpdateTaskListCheckboxAction)
 }

src/redux/note-details/reducer.ts

@@ -0,0 +1,194 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { Reducer } from 'redux'
+import { PresentFrontmatterExtractionResult } from '../../components/common/note-frontmatter/types'
+import { NoteFrontmatter } from '../../components/common/note-frontmatter/note-frontmatter'
+import { NoteDetails, NoteDetailsActions, NoteDetailsActionType } from './types'
+import { extractFrontmatter } from '../../components/common/note-frontmatter/extract-frontmatter'
+import { NoteDto } from '../../api/notes/types'
+import { initialState } from './initial-state'
+import { DateTime } from 'luxon'
+
+export const NoteDetailsReducer: Reducer<NoteDetails, NoteDetailsActions> = (
+  state: NoteDetails = initialState,
+  action: NoteDetailsActions
+) => {
+  switch (action.type) {
+    case NoteDetailsActionType.SET_DOCUMENT_CONTENT:
+      return buildStateFromDocumentContentUpdate(state, action.content)
+    case NoteDetailsActionType.UPDATE_NOTE_TITLE_BY_FIRST_HEADING:
+      return buildStateFromFirstHeadingUpdate(state, action.firstHeading)
+    case NoteDetailsActionType.SET_NOTE_DATA_FROM_SERVER:
+      return buildStateFromServerDto(action.dto)
+    case NoteDetailsActionType.UPDATE_TASK_LIST_CHECKBOX:
+      return buildStateFromTaskListUpdate(state, action.changedLine, action.checkboxChecked)
+    default:
+      return state
+  }
+}
+
+const TASK_REGEX = /(\s*(?:[-*+]|\d+[.)]) )(\[[ xX]])( .*)/
+
+/**
+ * Builds a {@link NoteDetails} redux state from a DTO received as an API response.
+ * @param dto The first DTO received from the API containing the relevant information about the note.
+ * @return An updated {@link NoteDetails} redux state.
+ */
+const buildStateFromServerDto = (dto: NoteDto): NoteDetails => {
+  const newState = convertNoteDtoToNoteDetails(dto)
+  return buildStateFromDocumentContentUpdate(newState, newState.documentContent)
+}
+
+/**
+ * Builds a {@link NoteDetails} redux state where a checkbox in the markdown content either gets checked or unchecked.
+ * @param state The previous redux state.
+ * @param changedLine The number of the line in which the checkbox should be updated.
+ * @param checkboxChecked true if the checkbox should be checked, false otherwise.
+ * @return An updated {@link NoteDetails} redux state.
+ */
+const buildStateFromTaskListUpdate = (
+  state: NoteDetails,
+  changedLine: number,
+  checkboxChecked: boolean
+): NoteDetails => {
+  const lines = state.documentContent.split('\n')
+  const results = TASK_REGEX.exec(lines[changedLine])
+  if (results) {
+    const before = results[1]
+    const after = results[3]
+    lines[changedLine] = `${before}[${checkboxChecked ? 'x' : ' '}]${after}`
+    return buildStateFromDocumentContentUpdate(state, lines.join('\n'))
+  }
+  return state
+}
+
+/**
+ * Builds a {@link NoteDetails} redux state from a fresh document content.
+ * @param state The previous redux state.
+ * @param documentContent The fresh document content consisting of the frontmatter and markdown part.
+ * @return An updated {@link NoteDetails} redux state.
+ */
+const buildStateFromDocumentContentUpdate = (state: NoteDetails, documentContent: string): NoteDetails => {
+  const frontmatterExtraction = extractFrontmatter(documentContent)
+  if (!frontmatterExtraction.frontmatterPresent) {
+    return {
+      ...state,
+      documentContent: documentContent,
+      markdownContent: documentContent,
+      rawFrontmatter: '',
+      frontmatter: initialState.frontmatter,
+      frontmatterRendererInfo: initialState.frontmatterRendererInfo
+    }
+  }
+  return buildStateFromFrontmatterUpdate(
+    {
+      ...state,
+      documentContent: documentContent,
+      markdownContent: documentContent.split('\n').slice(frontmatterExtraction.frontmatterLines).join('\n')
+    },
+    frontmatterExtraction
+  )
+}
+
+/**
+ * Builds a {@link NoteDetails} redux state from extracted frontmatter data.
+ * @param state The previous redux state.
+ * @param frontmatterExtraction The result of the frontmatter extraction containing the raw data and the line offset.
+ * @return An updated {@link NoteDetails} redux state.
+ */
+const buildStateFromFrontmatterUpdate = (
+  state: NoteDetails,
+  frontmatterExtraction: PresentFrontmatterExtractionResult
+): NoteDetails => {
+  if (frontmatterExtraction.rawFrontmatterText === state.rawFrontmatter) {
+    return state
+  }
+  try {
+    const frontmatter = NoteFrontmatter.createFromYaml(frontmatterExtraction.rawFrontmatterText)
+    return {
+      ...state,
+      rawFrontmatter: frontmatterExtraction.rawFrontmatterText,
+      frontmatter: frontmatter,
+      noteTitle: generateNoteTitle(frontmatter),
+      frontmatterRendererInfo: {
+        offsetLines: frontmatterExtraction.frontmatterLines,
+        deprecatedSyntax: frontmatter.deprecatedTagsSyntax,
+        frontmatterInvalid: false
+      }
+    }
+  } catch (e) {
+    return {
+      ...state,
+      rawFrontmatter: frontmatterExtraction.rawFrontmatterText,
+      frontmatter: initialState.frontmatter,
+      frontmatterRendererInfo: {
+        offsetLines: frontmatterExtraction.frontmatterLines,
+        deprecatedSyntax: false,
+        frontmatterInvalid: true
+      }
+    }
+  }
+}
+
+/**
+ * Builds a {@link NoteDetails} redux state with an updated note title from frontmatter data and the first heading.
+ * @param state The previous redux state.
+ * @param firstHeading The first heading of the document. Should be {@code undefined} if there is no such heading.
+ * @return An updated {@link NoteDetails} redux state.
+ */
+const buildStateFromFirstHeadingUpdate = (state: NoteDetails, firstHeading?: string): NoteDetails => {
+  return {
+    ...state,
+    firstHeading: firstHeading,
+    noteTitle: generateNoteTitle(state.frontmatter, firstHeading)
+  }
+}
+
+const generateNoteTitle = (frontmatter: NoteFrontmatter, firstHeading?: string) => {
+  if (frontmatter?.title && frontmatter?.title !== '') {
+    return frontmatter.title.trim()
+  } else if (
+    frontmatter?.opengraph &&
+    frontmatter?.opengraph.get('title') &&
+    frontmatter?.opengraph.get('title') !== ''
+  ) {
+    return (frontmatter?.opengraph.get('title') ?? firstHeading ?? '').trim()
+  } else {
+    return (firstHeading ?? firstHeading ?? '').trim()
+  }
+}
+
+/**
+ * Converts a note DTO from the HTTP API to a {@link NoteDetails} object.
+ * Note that the documentContent will be set but the markdownContent and rawFrontmatterContent are yet to be processed.
+ * @param note The NoteDTO as defined in the backend.
+ * @return The NoteDetails object corresponding to the DTO.
+ */
+const convertNoteDtoToNoteDetails = (note: NoteDto): NoteDetails => {
+  return {
+    documentContent: note.content,
+    markdownContent: '',
+    rawFrontmatter: '',
+    frontmatterRendererInfo: {
+      frontmatterInvalid: false,
+      deprecatedSyntax: false,
+      offsetLines: 0
+    },
+    frontmatter: initialState.frontmatter,
+    id: note.metadata.id,
+    noteTitle: initialState.noteTitle,
+    createTime: DateTime.fromISO(note.metadata.createTime),
+    lastChange: {
+      userName: note.metadata.updateUser.userName,
+      timestamp: DateTime.fromISO(note.metadata.updateTime)
+    },
+    firstHeading: initialState.firstHeading,
+    viewCount: note.metadata.viewCount,
+    alias: note.metadata.alias,
+    authorship: note.metadata.editedBy
+  }
+}

src/redux/note-details/reducers.ts

@@ -1,105 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-import { DateTime } from 'luxon'
-import { Reducer } from 'redux'
-import {
-  NoteFrontmatter,
-  NoteTextDirection,
-  NoteType
-} from '../../components/editor-page/note-frontmatter/note-frontmatter'
-import { NoteDetails, NoteDetailsActions, NoteDetailsActionType } from './types'
-import { noteDtoToNoteDetails } from '../../api/notes/dto-methods'
-
-export const initialState: NoteDetails = {
-  markdownContent: '',
-  id: '',
-  createTime: DateTime.fromSeconds(0),
-  lastChange: {
-    timestamp: DateTime.fromSeconds(0),
-    userName: ''
-  },
-  alias: '',
-  viewCount: 0,
-  authorship: [],
-  noteTitle: '',
-  firstHeading: '',
-  frontmatter: {
-    title: '',
-    description: '',
-    tags: [],
-    deprecatedTagsSyntax: false,
-    robots: '',
-    lang: 'en',
-    dir: NoteTextDirection.LTR,
-    breaks: true,
-    GA: '',
-    disqus: '',
-    type: NoteType.DOCUMENT,
-    opengraph: new Map<string, string>()
-  }
-}
-
-export const NoteDetailsReducer: Reducer<NoteDetails, NoteDetailsActions> = (
-  state: NoteDetails = initialState,
-  action: NoteDetailsActions
-) => {
-  switch (action.type) {
-    case NoteDetailsActionType.SET_DOCUMENT_CONTENT:
-      return {
-        ...state,
-        markdownContent: action.content
-      }
-    case NoteDetailsActionType.UPDATE_NOTE_TITLE_BY_FIRST_HEADING:
-      return {
-        ...state,
-        firstHeading: action.firstHeading,
-        noteTitle: generateNoteTitle(state.frontmatter, action.firstHeading)
-      }
-    case NoteDetailsActionType.SET_NOTE_DATA_FROM_SERVER:
-      return noteDtoToNoteDetails(action.note)
-    case NoteDetailsActionType.SET_NOTE_FRONTMATTER:
-      return {
-        ...state,
-        frontmatter: action.frontmatter,
-        noteTitle: generateNoteTitle(action.frontmatter, state.firstHeading)
-      }
-    case NoteDetailsActionType.SET_CHECKBOX_IN_MARKDOWN_CONTENT:
-      return {
-        ...state,
-        markdownContent: setCheckboxInMarkdownContent(state.markdownContent, action.lineInMarkdown, action.checked)
-      }
-    default:
-      return state
-  }
-}
-
-const TASK_REGEX = /(\s*(?:[-*+]|\d+[.)]) )(\[[ xX]])( .*)/
-const setCheckboxInMarkdownContent = (markdownContent: string, lineInMarkdown: number, checked: boolean): string => {
-  const lines = markdownContent.split('\n')
-  const results = TASK_REGEX.exec(lines[lineInMarkdown])
-  if (results) {
-    const before = results[1]
-    const after = results[3]
-    lines[lineInMarkdown] = `${before}[${checked ? 'x' : ' '}]${after}`
-    return lines.join('\n')
-  }
-  return markdownContent
-}
-
-const generateNoteTitle = (frontmatter: NoteFrontmatter, firstHeading?: string) => {
-  if (frontmatter?.title && frontmatter?.title !== '') {
-    return frontmatter.title.trim()
-  } else if (
-    frontmatter?.opengraph &&
-    frontmatter?.opengraph.get('title') &&
-    frontmatter?.opengraph.get('title') !== ''
-  ) {
-    return (frontmatter?.opengraph.get('title') ?? firstHeading ?? '').trim()
-  } else {
-    return (firstHeading ?? firstHeading ?? '').trim()
-  }
-}

src/redux/note-details/types.ts

@@ -6,24 +6,30 @@
 
 import { DateTime } from 'luxon'
 import { Action } from 'redux'
-import { NoteFrontmatter } from '../../components/editor-page/note-frontmatter/note-frontmatter'
+import { NoteFrontmatter } from '../../components/common/note-frontmatter/note-frontmatter'
 import { NoteDto } from '../../api/notes/types'
+import { RendererFrontmatterInfo } from '../../components/common/note-frontmatter/types'
 
 export enum NoteDetailsActionType {
-  SET_DOCUMENT_CONTENT = 'note-details/set',
+  SET_DOCUMENT_CONTENT = 'note-details/content/set',
   SET_NOTE_DATA_FROM_SERVER = 'note-details/data/server/set',
-  SET_NOTE_FRONTMATTER = 'note-details/frontmatter/set',
   UPDATE_NOTE_TITLE_BY_FIRST_HEADING = 'note-details/update-note-title-by-first-heading',
-  SET_CHECKBOX_IN_MARKDOWN_CONTENT = 'note-details/toggle-checkbox-in-markdown-content'
+  UPDATE_TASK_LIST_CHECKBOX = 'note-details/update-task-list-checkbox'
 }
-
 interface LastChange {
   userName: string
   timestamp: DateTime
 }
 
+/**
+ * Redux state containing the currently loaded note with its content and metadata.
+ */
 export interface NoteDetails {
+  documentContent: string
   markdownContent: string
+  rawFrontmatter: string
+  frontmatter: NoteFrontmatter
+  frontmatterRendererInfo: RendererFrontmatterInfo
   id: string
   createTime: DateTime
   lastChange: LastChange
@@ -32,38 +38,43 @@ export interface NoteDetails {
   authorship: string[]
   noteTitle: string
   firstHeading?: string
-  frontmatter: NoteFrontmatter
 }
 
 export type NoteDetailsActions =
-  | SetNoteDetailsAction
+  | SetNoteDocumentContentAction
   | SetNoteDetailsFromServerAction
   | UpdateNoteTitleByFirstHeadingAction
-  | SetNoteFrontmatterFromRenderingAction
-  | SetCheckboxInMarkdownContentAction
+  | UpdateTaskListCheckboxAction
 
-export interface SetNoteDetailsAction extends Action<NoteDetailsActionType> {
+/**
+ * Action for updating the document content of the currently loaded note.
+ */
+export interface SetNoteDocumentContentAction extends Action<NoteDetailsActionType> {
   type: NoteDetailsActionType.SET_DOCUMENT_CONTENT
   content: string
 }
 
+/**
+ * Action for overwriting the current state with the data received from the API.
+ */
 export interface SetNoteDetailsFromServerAction extends Action<NoteDetailsActionType> {
   type: NoteDetailsActionType.SET_NOTE_DATA_FROM_SERVER
-  note: NoteDto
+  dto: NoteDto
 }
 
+/**
+ * Action for updating the note title of the currently loaded note by using frontmatter data or the first heading.
+ */
 export interface UpdateNoteTitleByFirstHeadingAction extends Action<NoteDetailsActionType> {
   type: NoteDetailsActionType.UPDATE_NOTE_TITLE_BY_FIRST_HEADING
   firstHeading?: string
 }
 
-export interface SetNoteFrontmatterFromRenderingAction extends Action<NoteDetailsActionType> {
-  type: NoteDetailsActionType.SET_NOTE_FRONTMATTER
-  frontmatter: NoteFrontmatter
-}
-
-export interface SetCheckboxInMarkdownContentAction extends Action<NoteDetailsActionType> {
-  type: NoteDetailsActionType.SET_CHECKBOX_IN_MARKDOWN_CONTENT
-  lineInMarkdown: number
-  checked: boolean
+/**
+ * Action for manipulating the document content of the currently loaded note by changing the checked state of a task list checkbox.
+ */
+export interface UpdateTaskListCheckboxAction extends Action<NoteDetailsActionType> {
+  type: NoteDetailsActionType.UPDATE_TASK_LIST_CHECKBOX
+  changedLine: number
+  checkboxChecked: boolean
 }

yarn.lock

@@ -9508,11 +9508,6 @@ markdown-it-footnote@3.0.3:
   resolved "https://registry.yarnpkg.com/markdown-it-footnote/-/markdown-it-footnote-3.0.3.tgz#e0e4c0d67390a4c5f0c75f73be605c7c190ca4d8"
   integrity sha512-YZMSuCGVZAjzKMn+xqIco9d1cLGxbELHZ9do/TSYVzraooV8ypsppKNmUJ0fVH5ljkCInQAtFpm8Rb3eXSrt5w==
 
-markdown-it-front-matter@0.2.3:
-  version "0.2.3"
-  resolved "https://registry.yarnpkg.com/markdown-it-front-matter/-/markdown-it-front-matter-0.2.3.tgz#d6fa0f4b362e02086dd4ce8219fadf3f4c9cfa37"
-  integrity sha512-s9+rcClLmZsZc3YL8Awjg/YO/VdphlE20LJ9Bx5a8RAFLI5a1vq6Mll8kOzG6w/wy8yhFLBupaa6Mfd60GATkA==
-
 markdown-it-imsize@2.0.1:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/markdown-it-imsize/-/markdown-it-imsize-2.0.1.tgz#cca0427905d05338a247cb9ca9d968c5cddd5170"