Restructure replacers (#266)

* Restructure replacers

Signed-off-by: Tilman Vatteroth <tilman.vatteroth@tu-dortmund.de>

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

@@ -34,36 +34,21 @@ import { replaceQuoteExtraColor } from './regex-plugins/replace-quote-extra-colo
 import { replaceQuoteExtraTime } from './regex-plugins/replace-quote-extra-time'
 import { replaceVimeoLink } from './regex-plugins/replace-vimeo-link'
 import { replaceYouTubeLink } from './regex-plugins/replace-youtube-link'
-import { getGistReplacement } from './replace-components/gist/gist-frame'
+import { ComponentReplacer, SubNodeConverter } from './replace-components/ComponentReplacer'
-import { getHighlightedFence } from './replace-components/highlighted-fence/highlighted-fence'
+import { GistReplacer } from './replace-components/gist/gist-replacer'
-import { getMathJaxReplacement } from './replace-components/mathjax/mathjax-replacer'
+import { HighlightedCodeReplacer } from './replace-components/highlighted-fence/highlighted-fence-replacer'
-import { getPDFReplacement } from './replace-components/pdf/pdf-frame'
+import { MathjaxReplacer } from './replace-components/mathjax/mathjax-replacer'
-import { getQuoteOptionsReplacement } from './replace-components/quote-options/quote-options'
+import { PdfReplacer } from './replace-components/pdf/pdf-replacer'
-import { getTOCReplacement } from './replace-components/toc/toc-replacer'
+import { QuoteOptionsReplacer } from './replace-components/quote-options/quote-options-replacer'
-import { getVimeoReplacement } from './replace-components/vimeo/vimeo-frame'
+import { TocReplacer } from './replace-components/toc/toc-replacer'
-import { getYouTubeReplacement } from './replace-components/youtube/youtube-frame'
+import { VimeoReplacer } from './replace-components/vimeo/vimeo-replacer'
+import { YoutubeReplacer } from './replace-components/youtube/youtube-replacer'
 
 export interface MarkdownPreviewProps {
   content: string
 }
 
-export type SubNodeConverter = (node: DomElement, index: number) => ReactElement
+const createMarkdownIt = ():MarkdownIt => {
-export type ComponentReplacer = (node: DomElement, index: number, counterMap: Map<string, number>, nodeConverter: SubNodeConverter) => (ReactElement | undefined);
-type ComponentReplacer2Identifier2CounterMap = Map<ComponentReplacer, Map<string, number>>
-
-const allComponentReplacers: ComponentReplacer[] = [getYouTubeReplacement, getVimeoReplacement, getGistReplacement, getPDFReplacement, getTOCReplacement, getHighlightedFence, getQuoteOptionsReplacement, getMathJaxReplacement]
-
-const tryToReplaceNode = (node: DomElement, index:number, componentReplacer2Identifier2CounterMap: ComponentReplacer2Identifier2CounterMap, nodeConverter: SubNodeConverter) => {
-  return allComponentReplacers
-    .map((componentReplacer) => {
-      const identifier2CounterMap = componentReplacer2Identifier2CounterMap.get(componentReplacer) || new Map<string, number>()
-      return componentReplacer(node, index, identifier2CounterMap, nodeConverter)
-    })
-    .find((replacement) => !!replacement)
-}
-
-const MarkdownRenderer: React.FC<MarkdownPreviewProps> = ({ content }) => {
-  const markdownIt = useMemo(() => {
   const md = new MarkdownIt('default', {
     html: true,
     breaks: true,
@@ -119,15 +104,32 @@ const MarkdownRenderer: React.FC<MarkdownPreviewProps> = ({ content }) => {
   })
 
   return md
-  }, [])
+}
+
+const tryToReplaceNode = (node: DomElement, index: number, allReplacers: ComponentReplacer[], nodeConverter: SubNodeConverter) => {
+  return allReplacers
+    .map((componentReplacer) => componentReplacer.getReplacement(node, index, nodeConverter))
+    .find((replacement) => !!replacement)
+}
+
+const MarkdownRenderer: React.FC<MarkdownPreviewProps> = ({ content }) => {
+  const markdownIt = useMemo(createMarkdownIt, [])
 
   const result: ReactElement[] = useMemo(() => {
-    const componentReplacer2Identifier2CounterMap = new Map<ComponentReplacer, Map<string, number>>()
+    const allReplacers: ComponentReplacer[] = [
+      new GistReplacer(),
+      new YoutubeReplacer(),
+      new VimeoReplacer(),
+      new PdfReplacer(),
+      new TocReplacer(),
+      new HighlightedCodeReplacer(),
+      new QuoteOptionsReplacer(),
+      new MathjaxReplacer()
+    ]
     const html: string = markdownIt.render(content)
     const transform: Transform = (node, index) => {
-      const maybeReplacement = tryToReplaceNode(node, index, componentReplacer2Identifier2CounterMap,
+      const subNodeConverter = (subNode: DomElement, subIndex: number) => convertNodeToElement(subNode, subIndex, transform)
-        (subNode, subIndex) => convertNodeToElement(subNode, subIndex, transform))
+      return tryToReplaceNode(node, index, allReplacers, subNodeConverter) || convertNodeToElement(node, index, transform)
-      return maybeReplacement || convertNodeToElement(node, index, transform)
     }
     return ReactHtmlParser(html, { transform: transform })
   }, [content, markdownIt])

src/components/editor/markdown-renderer/replace-components/ComponentReplacer.ts

@@ -0,0 +1,8 @@
+import { DomElement } from 'domhandler'
+import { ReactElement } from 'react'
+
+export type SubNodeConverter = (node: DomElement, index: number) => ReactElement
+
+export interface ComponentReplacer {
+  getReplacement: (node: DomElement, index:number, subNodeConverter: SubNodeConverter) => (ReactElement|undefined)
+}

src/components/editor/markdown-renderer/replace-components/gist/gist-frame.tsx

@@ -1,9 +1,5 @@
 import React, { useCallback, useEffect, useMemo, useState } from 'react'
-import { ComponentReplacer } from '../../markdown-renderer'
-import { getAttributesFromCodiMdTag } from '../codi-md-tag-utils'
-import { OneClickEmbedding } from '../one-click-frame/one-click-embedding'
 import './gist-frame.scss'
-import preview from './gist-preview.png'
 
 export interface GistFrameProps {
   id: string
@@ -14,20 +10,6 @@ interface resizeEvent {
   id: string
 }
 
-const getElementReplacement:ComponentReplacer = (node, index:number, counterMap) => {
-  const attributes = getAttributesFromCodiMdTag(node, 'gist')
-  if (attributes && attributes.id) {
-    const gistId = attributes.id
-    const count = (counterMap.get(gistId) || 0) + 1
-    counterMap.set(gistId, count)
-    return (
-      <OneClickEmbedding previewContainerClassName={'gist-frame'} key={`gist_${gistId}_${count}`} loadingImageUrl={preview} hoverIcon={'github'} tooltip={'click to load gist'}>
-        <GistFrame id={gistId}/>
-      </OneClickEmbedding>
-    )
-  }
-}
-
 export const GistFrame: React.FC<GistFrameProps> = ({ id }) => {
   const iframeHtml = useMemo(() => {
     return (`
@@ -85,5 +67,3 @@ export const GistFrame: React.FC<GistFrameProps> = ({ id }) => {
       src={`data:text/html;base64,${btoa(iframeHtml)}`}/>
   )
 }
-
-export { getElementReplacement as getGistReplacement }

src/components/editor/markdown-renderer/replace-components/gist/gist-replacer.tsx

@@ -0,0 +1,25 @@
+import { DomElement } from 'domhandler'
+import React from 'react'
+import { getAttributesFromCodiMdTag } from '../codi-md-tag-utils'
+import { ComponentReplacer } from '../ComponentReplacer'
+import { OneClickEmbedding } from '../one-click-frame/one-click-embedding'
+import { GistFrame } from './gist-frame'
+import preview from './gist-preview.png'
+
+export class GistReplacer implements ComponentReplacer {
+  private counterMap: Map<string, number> = new Map<string, number>()
+
+  getReplacement (node: DomElement): React.ReactElement | undefined {
+    const attributes = getAttributesFromCodiMdTag(node, 'gist')
+    if (attributes && attributes.id) {
+      const gistId = attributes.id
+      const count = (this.counterMap.get(gistId) || 0) + 1
+      this.counterMap.set(gistId, count)
+      return (
+        <OneClickEmbedding previewContainerClassName={'gist-frame'} key={`gist_${gistId}_${count}`} loadingImageUrl={preview} hoverIcon={'github'} tooltip={'click to load gist'}>
+          <GistFrame id={gistId}/>
+        </OneClickEmbedding>
+      )
+    }
+  }
+}

src/components/editor/markdown-renderer/replace-components/highlighted-fence/highlighted-fence-replacer.tsx

@@ -0,0 +1,18 @@
+import { DomElement } from 'domhandler'
+import React from 'react'
+import { HighlightedCode } from '../../../../common/highlighted-code/highlighted-code'
+import { ComponentReplacer, SubNodeConverter } from '../ComponentReplacer'
+
+export class HighlightedCodeReplacer implements ComponentReplacer {
+  getReplacement (codeNode: DomElement, index: number, subNodeConverter: SubNodeConverter): React.ReactElement | undefined {
+    if (codeNode.name !== 'code' || !codeNode.attribs || !codeNode.attribs['data-highlight-language'] || !codeNode.children || !codeNode.children[0]) {
+      return
+    }
+
+    const language = codeNode.attribs['data-highlight-language']
+    const showGutter = codeNode.attribs['data-show-gutter'] !== undefined
+    const wrapLines = codeNode.attribs['data-wrap-lines'] !== undefined
+
+    return <HighlightedCode key={index} language={language} showGutter={showGutter} wrapLines={wrapLines} code={codeNode.children[0].data as string}/>
+  }
+}

src/components/editor/markdown-renderer/replace-components/highlighted-fence/highlighted-fence.tsx

@@ -1,16 +0,0 @@
-import { DomElement } from 'domhandler'
-import React, { ReactElement } from 'react'
-import { HighlightedCode } from '../../../../common/highlighted-code/highlighted-code'
-
-const getElementReplacement = (codeNode: DomElement, index: number, counterMap: Map<string, number>): (ReactElement | undefined) => {
-  if (codeNode.name !== 'code' || !codeNode.attribs || !codeNode.attribs['data-highlight-language'] || !codeNode.children || !codeNode.children[0]) {
-    return
-  }
-
-  const language = codeNode.attribs['data-highlight-language']
-  const showGutter = codeNode.attribs['data-show-gutter'] !== undefined
-  const wrapLines = codeNode.attribs['data-wrap-lines'] !== undefined
-  return <HighlightedCode key={index} language={language} showGutter={showGutter} wrapLines={wrapLines} code={codeNode.children[0].data as string}/>
-}
-
-export { getElementReplacement as getHighlightedFence }

src/components/editor/markdown-renderer/replace-components/mathjax/mathjax-replacer.tsx

@@ -1,7 +1,7 @@
-import React from 'react'
 import { DomElement } from 'domhandler'
-import { ComponentReplacer } from '../../markdown-renderer'
+import React from 'react'
 import MathJax from 'react-mathjax'
+import { ComponentReplacer, SubNodeConverter } from '../ComponentReplacer'
 
 const getNodeIfMathJaxBlock = (node: DomElement): (DomElement|undefined) => {
   if (node.name !== 'p' || !node.children || node.children.length !== 1) {
@@ -15,13 +15,13 @@ const getNodeIfInlineMathJax = (node: DomElement): (DomElement|undefined) => {
   return (node.name === 'codimd-mathjax' && node.attribs?.inline !== undefined) ? node : undefined
 }
 
-const getElementReplacement: ComponentReplacer = (node, index: number, counterMap) => {
+export class MathjaxReplacer implements ComponentReplacer {
+  getReplacement (node: DomElement, index: number, subNodeConverter: SubNodeConverter): React.ReactElement | undefined {
     const mathJax = getNodeIfMathJaxBlock(node) || getNodeIfInlineMathJax(node)
     if (mathJax?.children && mathJax.children[0]) {
       const mathJaxContent = mathJax.children[0]?.data as string
       const isInline = (mathJax.attribs?.inline) !== undefined
       return <MathJax.Node key={index} inline={isInline} formula={mathJaxContent}/>
     }
+  }
 }
-
-export { getElementReplacement as getMathJaxReplacement }

src/components/editor/markdown-renderer/replace-components/pdf/pdf-frame.tsx

@@ -1,20 +1,8 @@
-import { DomElement } from 'domhandler'
+import React from 'react'
-import React, { ReactElement } from 'react'
 import { ExternalLink } from '../../../../common/links/external-link'
-import { getAttributesFromCodiMdTag } from '../codi-md-tag-utils'
 import { OneClickEmbedding } from '../one-click-frame/one-click-embedding'
 import './pdf-frame.scss'
 
-const getElementReplacement = (node: DomElement, index:number, counterMap: Map<string, number>): (ReactElement | undefined) => {
-  const attributes = getAttributesFromCodiMdTag(node, 'pdf')
-  if (attributes && attributes.url) {
-    const pdfUrl = attributes.url
-    const count = (counterMap.get(pdfUrl) || 0) + 1
-    counterMap.set(pdfUrl, count)
-    return <PdfFrame key={`pdf_${pdfUrl}_${count}`} url={pdfUrl}/>
-  }
-}
-
 export interface PdfFrameProps {
   url: string
 }
@@ -30,5 +18,3 @@ export const PdfFrame: React.FC<PdfFrameProps> = ({ url }) => {
     </OneClickEmbedding>
   )
 }
-
-export { getElementReplacement as getPDFReplacement }

src/components/editor/markdown-renderer/replace-components/pdf/pdf-replacer.tsx

@@ -0,0 +1,19 @@
+import { DomElement } from 'domhandler'
+import React from 'react'
+import { getAttributesFromCodiMdTag } from '../codi-md-tag-utils'
+import { ComponentReplacer, SubNodeConverter } from '../ComponentReplacer'
+import { PdfFrame } from './pdf-frame'
+
+export class PdfReplacer implements ComponentReplacer {
+  private counterMap: Map<string, number> = new Map<string, number>()
+
+  getReplacement (node: DomElement, index: number, subNodeConverter: SubNodeConverter): React.ReactElement | undefined {
+    const attributes = getAttributesFromCodiMdTag(node, 'pdf')
+    if (attributes && attributes.url) {
+      const pdfUrl = attributes.url
+      const count = (this.counterMap.get(pdfUrl) || 0) + 1
+      this.counterMap.set(pdfUrl, count)
+      return <PdfFrame key={`pdf_${pdfUrl}_${count}`} url={pdfUrl}/>
+    }
+  }
+}

src/components/editor/markdown-renderer/replace-components/quote-options/quote-options-replacer.tsx

@@ -0,0 +1,42 @@
+import { DomElement } from 'domhandler'
+import { ComponentReplacer, SubNodeConverter } from '../ComponentReplacer'
+
+const isColorExtraElement = (node: DomElement | undefined): boolean => {
+  if (!node || !node.attribs || !node.attribs.class || !node.attribs['data-color']) {
+    return false
+  }
+  return (node.name === 'span' && node.attribs.class === 'quote-extra')
+}
+
+const findQuoteOptionsParent = (nodes: DomElement[]): DomElement | undefined => {
+  return nodes.find((child) => {
+    if (child.name !== 'p' || !child.children || child.children.length < 1) {
+      return false
+    }
+    return child.children.find(isColorExtraElement) !== undefined
+  })
+}
+
+export class QuoteOptionsReplacer implements ComponentReplacer {
+  getReplacement (node: DomElement, index: number, subNodeConverter: SubNodeConverter): React.ReactElement | undefined {
+    if (node.name !== 'blockquote' || !node.children || node.children.length < 1) {
+      return
+    }
+    const paragraph = findQuoteOptionsParent(node.children)
+    if (!paragraph) {
+      return
+    }
+    const childElements = paragraph.children || []
+    const optionsTag = childElements.find(isColorExtraElement)
+    if (!optionsTag) {
+      return
+    }
+    paragraph.children = childElements.filter(elem => !isColorExtraElement(elem))
+    const attributes = optionsTag.attribs
+    if (!attributes || !attributes['data-color']) {
+      return
+    }
+    node.attribs = Object.assign(node.attribs || {}, { style: `border-left-color: ${attributes['data-color']};` })
+    return subNodeConverter(node, index)
+  }
+}

src/components/editor/markdown-renderer/replace-components/quote-options/quote-options.tsx

@@ -1,43 +0,0 @@
-import { DomElement } from 'domhandler'
-import { ReactElement } from 'react'
-import { SubNodeConverter } from '../../markdown-renderer'
-
-const isColorExtraElement = (node: DomElement | undefined): boolean => {
-  if (!node || !node.attribs || !node.attribs.class || !node.attribs['data-color']) {
-    return false
-  }
-  return (node.name === 'span' && node.attribs.class === 'quote-extra')
-}
-
-const findQuoteOptionsParent = (nodes: DomElement[]): DomElement | undefined => {
-  return nodes.find((child) => {
-    if (child.name !== 'p' || !child.children || child.children.length < 1) {
-      return false
-    }
-    return child.children.find(isColorExtraElement) !== undefined
-  })
-}
-
-const getElementReplacement = (node: DomElement, index: number, counterMap: Map<string, number>, nodeConverter: SubNodeConverter): (ReactElement | undefined) => {
-  if (node.name !== 'blockquote' || !node.children || node.children.length < 1) {
-    return
-  }
-  const paragraph = findQuoteOptionsParent(node.children)
-  if (!paragraph) {
-    return
-  }
-  const childElements = paragraph.children || []
-  const optionsTag = childElements.find(isColorExtraElement)
-  if (!optionsTag) {
-    return
-  }
-  paragraph.children = childElements.filter(elem => !isColorExtraElement(elem))
-  const attributes = optionsTag.attribs
-  if (!attributes || !attributes['data-color']) {
-    return
-  }
-  node.attribs = Object.assign(node.attribs || {}, { style: `border-left-color: ${attributes['data-color']};` })
-  return nodeConverter(node, index)
-}
-
-export { getElementReplacement as getQuoteOptionsReplacement }

src/components/editor/markdown-renderer/replace-components/toc/toc-replacer.tsx

@@ -1,17 +1,17 @@
 import { DomElement } from 'domhandler'
-import { ReactElement } from 'react'
+import { ComponentReplacer, SubNodeConverter } from '../ComponentReplacer'
-import { SubNodeConverter } from '../../markdown-renderer'
 
-const getElementReplacement = (node: DomElement, index: number, counterMap: Map<string, number>, nodeConverter: SubNodeConverter): (ReactElement | undefined) => {
+export class TocReplacer implements ComponentReplacer {
-  if (node.name === 'p' && node.children && node.children.length === 1) {
+  getReplacement (node: DomElement, index: number, subNodeConverter: SubNodeConverter): React.ReactElement | undefined {
+    if (node.name !== 'p' || node.children?.length !== 1) {
+      return
+    }
     const possibleTocDiv = node.children[0]
     if (possibleTocDiv.name === 'div' && possibleTocDiv.attribs && possibleTocDiv.attribs.class &&
         possibleTocDiv.attribs.class === 'table-of-contents' && possibleTocDiv.children && possibleTocDiv.children.length === 1) {
       const listElement = possibleTocDiv.children[0]
       listElement.attribs = Object.assign(listElement.attribs || {}, { class: 'table-of-contents' })
-      return nodeConverter(listElement, index)
+      return subNodeConverter(listElement, index)
     }
   }
 }
-
-export { getElementReplacement as getTOCReplacement }

src/components/editor/markdown-renderer/replace-components/vimeo/vimeo-frame.tsx

@@ -1,18 +1,6 @@
 import React, { useCallback } from 'react'
-import { ComponentReplacer } from '../../markdown-renderer'
-import { getAttributesFromCodiMdTag } from '../codi-md-tag-utils'
 import { OneClickEmbedding } from '../one-click-frame/one-click-embedding'
 
-const getElementReplacement:ComponentReplacer = (node, index:number, counterMap) => {
-  const attributes = getAttributesFromCodiMdTag(node, 'vimeo')
-  if (attributes && attributes.id) {
-    const videoId = attributes.id
-    const count = (counterMap.get(videoId) || 0) + 1
-    counterMap.set(videoId, count)
-    return <VimeoFrame key={`vimeo_${videoId}_${count}`} id={videoId}/>
-  }
-}
-
 interface VimeoApiResponse {
   // Vimeo uses strange names for their fields. ESLint doesn't like that.
   // eslint-disable-next-line camelcase
@@ -50,5 +38,3 @@ export const VimeoFrame: React.FC<VimeoFrameProps> = ({ id }) => {
     </OneClickEmbedding>
   )
 }
-
-export { getElementReplacement as getVimeoReplacement }

src/components/editor/markdown-renderer/replace-components/vimeo/vimeo-replacer.tsx

@@ -0,0 +1,19 @@
+import { DomElement } from 'domhandler'
+import React from 'react'
+import { getAttributesFromCodiMdTag } from '../codi-md-tag-utils'
+import { ComponentReplacer } from '../ComponentReplacer'
+import { VimeoFrame } from './vimeo-frame'
+
+export class VimeoReplacer implements ComponentReplacer {
+  private counterMap: Map<string, number> = new Map<string, number>()
+
+  getReplacement (node: DomElement): React.ReactElement | undefined {
+    const attributes = getAttributesFromCodiMdTag(node, 'vimeo')
+    if (attributes && attributes.id) {
+      const videoId = attributes.id
+      const count = (this.counterMap.get(videoId) || 0) + 1
+      this.counterMap.set(videoId, count)
+      return <VimeoFrame key={`vimeo_${videoId}_${count}`} id={videoId}/>
+    }
+  }
+}

src/components/editor/markdown-renderer/replace-components/youtube/youtube-frame.tsx

@@ -1,18 +1,6 @@
 import React from 'react'
-import { ComponentReplacer } from '../../markdown-renderer'
-import { getAttributesFromCodiMdTag } from '../codi-md-tag-utils'
 import { OneClickEmbedding } from '../one-click-frame/one-click-embedding'
 
-const getElementReplacement: ComponentReplacer = (node, index:number, counterMap) => {
-  const attributes = getAttributesFromCodiMdTag(node, 'youtube')
-  if (attributes && attributes.id) {
-    const videoId = attributes.id
-    const count = (counterMap.get(videoId) || 0) + 1
-    counterMap.set(videoId, count)
-    return <YouTubeFrame key={`youtube_${videoId}_${count}`} id={videoId}/>
-  }
-}
-
 export interface YouTubeFrameProps {
   id: string
 }
@@ -28,5 +16,3 @@ export const YouTubeFrame: React.FC<YouTubeFrameProps> = ({ id }) => {
     </OneClickEmbedding>
   )
 }
-
-export { getElementReplacement as getYouTubeReplacement }

src/components/editor/markdown-renderer/replace-components/youtube/youtube-replacer.tsx

@@ -0,0 +1,19 @@
+import { DomElement } from 'domhandler'
+import React from 'react'
+import { getAttributesFromCodiMdTag } from '../codi-md-tag-utils'
+import { ComponentReplacer } from '../ComponentReplacer'
+import { YouTubeFrame } from './youtube-frame'
+
+export class YoutubeReplacer implements ComponentReplacer {
+  private counterMap: Map<string, number> = new Map<string, number>()
+
+  getReplacement (node: DomElement): React.ReactElement | undefined {
+    const attributes = getAttributesFromCodiMdTag(node, 'youtube')
+    if (attributes && attributes.id) {
+      const videoId = attributes.id
+      const count = (this.counterMap.get(videoId) || 0) + 1
+      this.counterMap.set(videoId, count)
+      return <YouTubeFrame key={`youtube_${videoId}_${count}`} id={videoId}/>
+    }
+  }
+}