feat(layout): add afterBody

Jacky Zhao

2024-07-10 247625c4f538a113617e553e1ed3c74d94545e62

 quartz/plugins/transformers/ofm.ts

@@ -2,13 +2,15 @@
import { Root, Html, BlockContent, DefinitionContent, Paragraph, Code } from "mdast"
import { Element, Literal, Root as HtmlRoot } from "hast"
import { ReplaceFunction, findAndReplace as mdastFindReplace } from "mdast-util-find-and-replace"
import { slug as slugAnchor } from "github-slugger"
import rehypeRaw from "rehype-raw"
import { visit } from "unist-util-visit"
import { SKIP, visit } from "unist-util-visit"
import path from "path"
import { splitAnchor } from "../../util/path"
import { JSResource } from "../../util/resources"
// @ts-ignore
import calloutScript from "../../components/scripts/callout.inline.ts"
// @ts-ignore
import checkboxScript from "../../components/scripts/checkbox.inline.ts"
import { FilePath, pathToRoot, slugTag, slugifyFilePath } from "../../util/path"
import { toHast } from "mdast-util-to-hast"
import { toHtml } from "hast-util-to-html"
@@ -23,8 +25,12 @@
  callouts: boolean
  mermaid: boolean
  parseTags: boolean
  parseArrows: boolean
  parseBlockReferences: boolean
  enableInHtmlEmbed: boolean
  enableYouTubeEmbed: boolean
  enableVideoEmbed: boolean
  enableCheckbox: boolean
}

const defaultOptions: Options = {
@@ -34,43 +40,15 @@
  callouts: true,
  mermaid: true,
  parseTags: true,
  parseArrows: true,
  parseBlockReferences: true,
  enableInHtmlEmbed: false,
  enableYouTubeEmbed: true,
  enableVideoEmbed: true,
  enableCheckbox: false,
}

const icons = {
  infoIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="10"></circle><line x1="12" y1="16" x2="12" y2="12"></line><line x1="12" y1="8" x2="12.01" y2="8"></line></svg>`,
  pencilIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><line x1="18" y1="2" x2="22" y2="6"></line><path d="M7.5 20.5 19 9l-4-4L3.5 16.5 2 22z"></path></svg>`,
  clipboardListIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><rect x="8" y="2" width="8" height="4" rx="1" ry="1"></rect><path d="M16 4h2a2 2 0 0 1 2 2v14a2 2 0 0 1-2 2H6a2 2 0 0 1-2-2V6a2 2 0 0 1 2-2h2"></path><path d="M12 11h4"></path><path d="M12 16h4"></path><path d="M8 11h.01"></path><path d="M8 16h.01"></path></svg>`,
  checkCircleIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M12 22c5.523 0 10-4.477 10-10S17.523 2 12 2 2 6.477 2 12s4.477 10 10 10z"></path><path d="m9 12 2 2 4-4"></path></svg>`,
  flameIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M8.5 14.5A2.5 2.5 0 0 0 11 12c0-1.38-.5-2-1-3-1.072-2.143-.224-4.054 2-6 .5 2.5 2 4.9 4 6.5 2 1.6 3 3.5 3 5.5a7 7 0 1 1-14 0c0-1.153.433-2.294 1-3a2.5 2.5 0 0 0 2.5 2.5z"></path></svg>`,
  checkIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polyline points="20 6 9 17 4 12"></polyline></svg>`,
  helpCircleIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="10"></circle><path d="M9.09 9a3 3 0 0 1 5.83 1c0 2-3 3-3 3"></path><line x1="12" y1="17" x2="12.01" y2="17"></line></svg>`,
  alertTriangleIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="m21.73 18-8-14a2 2 0 0 0-3.48 0l-8 14A2 2 0 0 0 4 21h16a2 2 0 0 0 1.73-3Z"></path><line x1="12" y1="9" x2="12" y2="13"></line><line x1="12" y1="17" x2="12.01" y2="17"></line></svg>`,
  xIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><line x1="18" y1="6" x2="6" y2="18"></line><line x1="6" y1="6" x2="18" y2="18"></line></svg>`,
  zapIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polygon points="13 2 3 14 12 14 11 22 21 10 12 10 13 2"></polygon></svg>`,
  bugIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><rect width="8" height="14" x="8" y="6" rx="4"></rect><path d="m19 7-3 2"></path><path d="m5 7 3 2"></path><path d="m19 19-3-2"></path><path d="m5 19 3-2"></path><path d="M20 13h-4"></path><path d="M4 13h4"></path><path d="m10 4 1 2"></path><path d="m14 4-1 2"></path></svg>`,
  listIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><line x1="8" y1="6" x2="21" y2="6"></line><line x1="8" y1="12" x2="21" y2="12"></line><line x1="8" y1="18" x2="21" y2="18"></line><line x1="3" y1="6" x2="3.01" y2="6"></line><line x1="3" y1="12" x2="3.01" y2="12"></line><line x1="3" y1="18" x2="3.01" y2="18"></line></svg>`,
  quoteIcon: `<svg xmlns="http://www.w3.org/2000/svg" width="100%" height="100%" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M3 21c3 0 7-1 7-8V5c0-1.25-.756-2.017-2-2H4c-1.25 0-2 .75-2 1.972V11c0 1.25.75 2 2 2 1 0 1 0 1 1v1c0 1-1 2-2 2s-1 .008-1 1.031V20c0 1 0 1 1 1z"></path><path d="M15 21c3 0 7-1 7-8V5c0-1.25-.757-2.017-2-2h-4c-1.25 0-2 .75-2 1.972V11c0 1.25.75 2 2 2h.75c0 2.25.25 4-2.75 4v3c0 1 0 1 1 1z"></path></svg>`,
}

const callouts = {
  note: icons.pencilIcon,
  abstract: icons.clipboardListIcon,
  info: icons.infoIcon,
  todo: icons.checkCircleIcon,
  tip: icons.flameIcon,
  success: icons.checkIcon,
  question: icons.helpCircleIcon,
  warning: icons.alertTriangleIcon,
  failure: icons.xIcon,
  danger: icons.zapIcon,
  bug: icons.bugIcon,
  example: icons.listIcon,
  quote: icons.quoteIcon,
}

const calloutMapping: Record<string, keyof typeof callouts> = {
const calloutMapping = {
  note: "note",
  abstract: "abstract",
  summary: "abstract",
@@ -98,35 +76,65 @@
  example: "example",
  quote: "quote",
  cite: "quote",
} as const

const arrowMapping: Record<string, string> = {
  "->": "&rarr;",
  "-->": "&rArr;",
  "=>": "&rArr;",
  "==>": "&rArr;",
  "<-": "&larr;",
  "<--": "&lArr;",
  "<=": "&lArr;",
  "<==": "&lArr;",
}

function canonicalizeCallout(calloutName: string): keyof typeof callouts {
  let callout = calloutName.toLowerCase() as keyof typeof calloutMapping
  return calloutMapping[callout] ?? "note"
function canonicalizeCallout(calloutName: string): keyof typeof calloutMapping {
  const normalizedCallout = calloutName.toLowerCase() as keyof typeof calloutMapping
  // if callout is not recognized, make it a custom one
  return calloutMapping[normalizedCallout] ?? calloutName
}

export const externalLinkRegex = /^https?:\/\//i

// !?               -> optional embedding
// \[\[             -> open brace
// ([^\[\]\|\#]+)   -> one or more non-special characters ([,],|, or #) (name)
// (#[^\[\]\|\#]+)? -> # then one or more non-special characters (heading link)
// (|[^\[\]\|\#]+)? -> | then one or more non-special characters (alias)
export const arrowRegex = new RegExp(/(-{1,2}>|={1,2}>|<-{1,2}|<={1,2})/g)

// !?                 -> optional embedding
// \[\[               -> open brace
// ([^\[\]\|\#]+)     -> one or more non-special characters ([,],|, or #) (name)
// (#[^\[\]\|\#]+)?   -> # then one or more non-special characters (heading link)
// (\\?\|[^\[\]\#]+)? -> optional escape \ then | then one or more non-special characters (alias)
export const wikilinkRegex = new RegExp(
  /!?\[\[([^\[\]\|\#]+)?(#+[^\[\]\|\#]+)?(\|[^\[\]\|\#]+)?\]\]/,
  "g",
  /!?\[\[([^\[\]\|\#\\]+)?(#+[^\[\]\|\#\\]+)?(\\?\|[^\[\]\#]+)?\]\]/g,
)
const highlightRegex = new RegExp(/==([^=]+)==/, "g")
const commentRegex = new RegExp(/%%(.+)%%/, "g")

// ^\|([^\n])+\|\n(\|) -> matches the header row
// ( ?:?-{3,}:? ?\|)+  -> matches the header row separator
// (\|([^\n])+\|\n)+   -> matches the body rows
export const tableRegex = new RegExp(/^\|([^\n])+\|\n(\|)( ?:?-{3,}:? ?\|)+\n(\|([^\n])+\|\n?)+/gm)

// matches any wikilink, only used for escaping wikilinks inside tables
export const tableWikilinkRegex = new RegExp(/(!?\[\[[^\]]*?\]\])/g)

const highlightRegex = new RegExp(/==([^=]+)==/g)
const commentRegex = new RegExp(/%%[\s\S]*?%%/g)
// from https://github.com/escwxyz/remark-obsidian-callout/blob/main/src/index.ts
const calloutRegex = new RegExp(/^\[\!(\w+)\]([+-]?)/)
const calloutLineRegex = new RegExp(/^> *\[\!\w+\][+-]?.*$/, "gm")
const calloutRegex = new RegExp(/^\[\!(\w+)\|?(.+?)?\]([+-]?)/)
const calloutLineRegex = new RegExp(/^> *\[\!\w+\|?.*?\][+-]?.*$/gm)
// (?:^| )              -> non-capturing group, tag should start be separated by a space or be the start of the line
// #(...)               -> capturing group, tag itself must start with #
// (?:[-_\p{L}\d\p{Z}])+       -> non-capturing group, non-empty string of (Unicode-aware) alpha-numeric characters and symbols, hyphens and/or underscores
// (?:\/[-_\p{L}\d\p{Z}]+)*)   -> non-capturing group, matches an arbitrary number of tag strings separated by "/"
const tagRegex = new RegExp(/(?:^| )#((?:[-_\p{L}\p{Emoji}\d])+(?:\/[-_\p{L}\p{Emoji}\d]+)*)/, "gu")
const blockReferenceRegex = new RegExp(/\^([A-Za-z0-9]+)$/, "g")
const tagRegex = new RegExp(
  /(?:^| )#((?:[-_\p{L}\p{Emoji}\p{M}\d])+(?:\/[-_\p{L}\p{Emoji}\p{M}\d]+)*)/gu,
)
const blockReferenceRegex = new RegExp(/\^([-_A-Za-z0-9]+)$/g)
const ytLinkRegex = /^.*(youtu.be\/|v\/|u\/\w\/|embed\/|watch\?v=|\&v=)([^#\&\?]*).*/
const ytPlaylistLinkRegex = /[?&]list=([^#?&]*)/
const videoExtensionRegex = new RegExp(/\.(mp4|webm|ogg|avi|mov|flv|wmv|mkv|mpg|mpeg|3gp|m4v)$/)
const wikilinkImageEmbedRegex = new RegExp(
  /^(?<alt>(?!^\d*x?\d*$).*?)?(\|?\s*?(?<width>\d+)(x(?<height>\d+))?)?$/,
)

export const ObsidianFlavoredMarkdown: QuartzTransformerPlugin<Partial<Options> | undefined> = (
  userOpts,
@@ -141,13 +149,22 @@
  return {
    name: "ObsidianFlavoredMarkdown",
    textTransform(_ctx, src) {
      // do comments at text level
      if (opts.comments) {
        if (src instanceof Buffer) {
          src = src.toString()
        }

        src = src.replace(commentRegex, "")
      }

      // pre-transform blockquotes
      if (opts.callouts) {
        if (src instanceof Buffer) {
          src = src.toString()
        }

        src = src.replaceAll(calloutLineRegex, (value) => {
        src = src.replace(calloutLineRegex, (value) => {
          // force newline after title of callout
          return value + "\n> "
        })
@@ -159,13 +176,27 @@
          src = src.toString()
        }

        src = src.replaceAll(wikilinkRegex, (value, ...capture) => {
        // replace all wikilinks inside a table first
        src = src.replace(tableRegex, (value) => {
          // escape all aliases and headers in wikilinks inside a table
          return value.replace(tableWikilinkRegex, (_value, raw) => {
            // const [raw]: (string | undefined)[] = capture
            let escaped = raw ?? ""
            escaped = escaped.replace("#", "\\#")
            // escape pipe characters if they are not already escaped
            escaped = escaped.replace(/((^|[^\\])(\\\\)*)\|/g, "$1\\|")

            return escaped
          })
        })

        // replace all other wikilinks
        src = src.replace(wikilinkRegex, (value, ...capture) => {
          const [rawFp, rawHeader, rawAlias]: (string | undefined)[] = capture

          const fp = rawFp ?? ""
          const anchor = rawHeader?.trim().replace(/^#+/, "")
          const [fp, anchor] = splitAnchor(`${rawFp ?? ""}${rawHeader ?? ""}`)
          const blockRef = Boolean(anchor?.startsWith("^")) ? "^" : ""
          const displayAnchor = anchor ? `#${blockRef}${slugAnchor(anchor)}` : ""
          const displayAnchor = anchor ? `#${blockRef}${anchor.trim().replace(/^#+/, "")}` : ""
          const displayAlias = rawAlias ?? rawHeader?.replace("#", "|") ?? ""
          const embedDisplay = value.startsWith("!") ? "!" : ""

@@ -179,7 +210,7 @@

      return src
    },
    markdownPlugins() {
    markdownPlugins(_ctx) {
      const plugins: PluggableList = []

      // regex replacements
@@ -202,10 +233,10 @@
                  const ext: string = path.extname(fp).toLowerCase()
                  const url = slugifyFilePath(fp as FilePath)
                  if ([".png", ".jpg", ".jpeg", ".gif", ".bmp", ".svg", ".webp"].includes(ext)) {
                    const dims = alias ?? ""
                    let [width, height] = dims.split("x", 2)
                    width ||= "auto"
                    height ||= "auto"
                    const match = wikilinkImageEmbedRegex.exec(alias ?? "")
                    const alt = match?.groups?.alt ?? ""
                    const width = match?.groups?.width ?? "auto"
                    const height = match?.groups?.height ?? "auto"
                    return {
                      type: "image",
                      url,
@@ -213,6 +244,7 @@
                        hProperties: {
                          width,
                          height,
                          alt,
                        },
                      },
                    }
@@ -233,12 +265,12 @@
                      type: "html",
                      value: `<iframe src="${url}"></iframe>`,
                    }
                  } else if (ext === "") {
                  } else {
                    const block = anchor
                    return {
                      type: "html",
                      data: { hProperties: { transclude: true } },
                      value: `<blockquote class="transclude" data-url="${url}" data-block="${block}"><a href="${
                      value: `<blockquote class="transclude" data-url="${url}" data-block="${block}" data-embed-alias="${alias}"><a href="${
                        url + anchor
                      }" class="transclude-inner">Transclude of ${url}${block}</a></blockquote>`,
                    }
@@ -276,13 +308,15 @@
            ])
          }

          if (opts.comments) {
          if (opts.parseArrows) {
            replacements.push([
              commentRegex,
              (_value: string, ..._capture: string[]) => {
              arrowRegex,
              (value: string, ..._capture: string[]) => {
                const maybeArrow = arrowMapping[value]
                if (maybeArrow === undefined) return SKIP
                return {
                  type: "text",
                  value: "",
                  type: "html",
                  value: `<span>${maybeArrow}</span>`,
                }
              },
            ])
@@ -298,8 +332,9 @@
                }

                tag = slugTag(tag)
                if (file.data.frontmatter && !file.data.frontmatter.tags.includes(tag)) {
                  file.data.frontmatter.tags.push(tag)
                if (file.data.frontmatter) {
                  const noteTags = file.data.frontmatter.tags ?? []
                  file.data.frontmatter.tags = [...new Set([...noteTags, tag])]
                }

                return {
@@ -313,7 +348,7 @@
                  children: [
                    {
                      type: "text",
                      value: `#${tag}`,
                      value: tag,
                    },
                  ],
                }
@@ -327,7 +362,7 @@
                if (typeof replace === "string") {
                  node.value = node.value.replace(regex, replace)
                } else {
                  node.value = node.value.replaceAll(regex, (substring: string, ...args) => {
                  node.value = node.value.replace(regex, (substring: string, ...args) => {
                    const replaceValue = replace(substring, ...args)
                    if (typeof replaceValue === "string") {
                      return replaceValue
@@ -343,11 +378,28 @@
              }
            })
          }

          mdastFindReplace(tree, replacements)
        }
      })

      if (opts.enableVideoEmbed) {
        plugins.push(() => {
          return (tree: Root, _file) => {
            visit(tree, "image", (node, index, parent) => {
              if (parent && index != undefined && videoExtensionRegex.test(node.url)) {
                const newNode: Html = {
                  type: "html",
                  value: `<video controls src="${node.url}"></video>`,
                }

                parent.children.splice(index, 1, newNode)
                return SKIP
              }
            })
          }
        })
      }

      if (opts.callouts) {
        plugins.push(() => {
          return (tree: Root, _file) => {
@@ -356,43 +408,45 @@
                return
              }

              // find first line
              const firstChild = node.children[0]
              // find first line and callout content
              const [firstChild, ...calloutContent] = node.children
              if (firstChild.type !== "paragraph" || firstChild.children[0]?.type !== "text") {
                return
              }

              const text = firstChild.children[0].value
              const restChildren = firstChild.children.slice(1)
              const restOfTitle = firstChild.children.slice(1)
              const [firstLine, ...remainingLines] = text.split("\n")
              const remainingText = remainingLines.join("\n")

              const match = firstLine.match(calloutRegex)
              if (match && match.input) {
                const [calloutDirective, typeString, collapseChar] = match
                const calloutType = canonicalizeCallout(
                  typeString.toLowerCase() as keyof typeof calloutMapping,
                )
                const [calloutDirective, typeString, calloutMetaData, collapseChar] = match
                const calloutType = canonicalizeCallout(typeString.toLowerCase())
                const collapse = collapseChar === "+" || collapseChar === "-"
                const defaultState = collapseChar === "-" ? "collapsed" : "expanded"
                const titleContent =
                  match.input.slice(calloutDirective.length).trim() || capitalize(calloutType)
                const titleContent = match.input.slice(calloutDirective.length).trim()
                const useDefaultTitle = titleContent === "" && restOfTitle.length === 0
                const titleNode: Paragraph = {
                  type: "paragraph",
                  children: [{ type: "text", value: titleContent + " " }, ...restChildren],
                  children: [
                    {
                      type: "text",
                      value: useDefaultTitle ? capitalize(typeString) : titleContent + " ",
                    },
                    ...restOfTitle,
                  ],
                }
                const title = mdastToHtml(titleNode)

                const toggleIcon = `<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="fold">
                  <polyline points="6 9 12 15 18 9"></polyline>
                </svg>`
                const toggleIcon = `<div class="fold-callout-icon"></div>`

                const titleHtml: Html = {
                  type: "html",
                  value: `<div
                  class="callout-title"
                >
                  <div class="callout-icon">${callouts[calloutType]}</div>
                  <div class="callout-icon"></div>
                  <div class="callout-title-inner">${title}</div>
                  ${collapse ? toggleIcon : ""}
                </div>`,
@@ -414,17 +468,39 @@
                // replace first line of blockquote with title and rest of the paragraph text
                node.children.splice(0, 1, ...blockquoteContent)

                const classNames = ["callout", calloutType]
                if (collapse) {
                  classNames.push("is-collapsible")
                }
                if (defaultState === "collapsed") {
                  classNames.push("is-collapsed")
                }

                // add properties to base blockquote
                node.data = {
                  hProperties: {
                    ...(node.data?.hProperties ?? {}),
                    className: `callout ${collapse ? "is-collapsible" : ""} ${
                      defaultState === "collapsed" ? "is-collapsed" : ""
                    }`,
                    className: classNames.join(" "),
                    "data-callout": calloutType,
                    "data-callout-fold": collapse,
                    "data-callout-metadata": calloutMetaData,
                  },
                }

                // Add callout-content class to callout body if it has one.
                if (calloutContent.length > 0) {
                  const contentData: BlockContent | DefinitionContent = {
                    data: {
                      hProperties: {
                        className: "callout-content",
                      },
                      hName: "div",
                    },
                    type: "blockquote",
                    children: [...calloutContent],
                  }
                  node.children = [node.children[0], contentData]
                }
              }
            })
          }
@@ -488,12 +564,35 @@
                    last.value = last.value.slice(0, -matches[0].length)
                    const block = matches[0].slice(1)

                    if (!Object.keys(file.data.blocks!).includes(block)) {
                      node.properties = {
                        ...node.properties,
                        id: block,
                    if (last.value === "") {
                      // this is an inline block ref but the actual block
                      // is the previous element above it
                      let idx = (index ?? 1) - 1
                      while (idx >= 0) {
                        const element = parent?.children.at(idx)
                        if (!element) break
                        if (element.type !== "element") {
                          idx -= 1
                        } else {
                          if (!Object.keys(file.data.blocks!).includes(block)) {
                            element.properties = {
                              ...element.properties,
                              id: block,
                            }
                            file.data.blocks![block] = element
                          }
                          return
                        }
                      }
                      file.data.blocks![block] = node
                    } else {
                      // normal paragraph transclude
                      if (!Object.keys(file.data.blocks!).includes(block)) {
                        node.properties = {
                          ...node.properties,
                          id: block,
                        }
                        file.data.blocks![block] = node
                      }
                    }
                  }
                }
@@ -505,11 +604,76 @@
        })
      }

      if (opts.enableYouTubeEmbed) {
        plugins.push(() => {
          return (tree: HtmlRoot) => {
            visit(tree, "element", (node) => {
              if (node.tagName === "img" && typeof node.properties.src === "string") {
                const match = node.properties.src.match(ytLinkRegex)
                const videoId = match && match[2].length == 11 ? match[2] : null
                const playlistId = node.properties.src.match(ytPlaylistLinkRegex)?.[1]
                if (videoId) {
                  // YouTube video (with optional playlist)
                  node.tagName = "iframe"
                  node.properties = {
                    class: "external-embed",
                    allow: "fullscreen",
                    frameborder: 0,
                    width: "600px",
                    height: "350px",
                    src: playlistId
                      ? `https://www.youtube.com/embed/${videoId}?list=${playlistId}`
                      : `https://www.youtube.com/embed/${videoId}`,
                  }
                } else if (playlistId) {
                  // YouTube playlist only.
                  node.tagName = "iframe"
                  node.properties = {
                    class: "external-embed",
                    allow: "fullscreen",
                    frameborder: 0,
                    width: "600px",
                    height: "350px",
                    src: `https://www.youtube.com/embed/videoseries?list=${playlistId}`,
                  }
                }
              }
            })
          }
        })
      }

      if (opts.enableCheckbox) {
        plugins.push(() => {
          return (tree: HtmlRoot, _file) => {
            visit(tree, "element", (node) => {
              if (node.tagName === "input" && node.properties.type === "checkbox") {
                const isChecked = node.properties?.checked ?? false
                node.properties = {
                  type: "checkbox",
                  disabled: false,
                  checked: isChecked,
                  class: "checkbox-toggle",
                }
              }
            })
          }
        })
      }

      return plugins
    },
    externalResources() {
      const js: JSResource[] = []

      if (opts.enableCheckbox) {
        js.push({
          script: checkboxScript,
          loadTime: "afterDOMReady",
          contentType: "inline",
        })
      }

      if (opts.callouts) {
        js.push({
          script: calloutScript,
@@ -521,17 +685,22 @@
      if (opts.mermaid) {
        js.push({
          script: `
          import mermaid from 'https://cdn.jsdelivr.net/npm/mermaid/dist/mermaid.esm.min.mjs';
          const darkMode = document.documentElement.getAttribute('saved-theme') === 'dark'
          mermaid.initialize({
            startOnLoad: false,
            securityLevel: 'loose',
            theme: darkMode ? 'dark' : 'default'
          });
          let mermaidImport = undefined
          document.addEventListener('nav', async () => {
            await mermaid.run({
              querySelector: '.mermaid'
            })
            if (document.querySelector("code.mermaid")) {
              mermaidImport ||= await import('https://cdnjs.cloudflare.com/ajax/libs/mermaid/10.7.0/mermaid.esm.min.mjs')
              const mermaid = mermaidImport.default
              const darkMode = document.documentElement.getAttribute('saved-theme') === 'dark'
              mermaid.initialize({
                startOnLoad: false,
                securityLevel: 'loose',
                theme: darkMode ? 'dark' : 'default'
              })

              await mermaid.run({
                querySelector: '.mermaid'
              })
            }
          });
          `,
          loadTime: "afterDOMReady",