76 lines
2.0 KiB
TypeScript
76 lines
2.0 KiB
TypeScript
import { QuartzTransformerPlugin } from "../types"
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import { Root } from "mdast"
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import { visit } from "unist-util-visit"
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import { toString } from "mdast-util-to-string"
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import Slugger from "github-slugger"
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export interface Options {
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maxDepth: 1 | 2 | 3 | 4 | 5 | 6
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minEntries: number
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showByDefault: boolean
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collapseByDefault: boolean
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}
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const defaultOptions: Options = {
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maxDepth: 3,
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minEntries: 1,
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showByDefault: true,
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collapseByDefault: false,
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}
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interface TocEntry {
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depth: number
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text: string
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slug: string // this is just the anchor (#some-slug), not the canonical slug
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}
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const slugAnchor = new Slugger()
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export const TableOfContents: QuartzTransformerPlugin<Partial<Options> | undefined> = (
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userOpts,
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) => {
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const opts = { ...defaultOptions, ...userOpts }
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return {
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name: "TableOfContents",
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markdownPlugins() {
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return [
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() => {
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return async (tree: Root, file) => {
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const display = file.data.frontmatter?.enableToc ?? opts.showByDefault
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if (display) {
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slugAnchor.reset()
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const toc: TocEntry[] = []
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let highestDepth: number = opts.maxDepth
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visit(tree, "heading", (node) => {
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if (node.depth <= opts.maxDepth) {
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const text = toString(node)
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highestDepth = Math.min(highestDepth, node.depth)
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toc.push({
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depth: node.depth,
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text,
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slug: slugAnchor.slug(text),
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})
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}
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})
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if (toc.length > 0 && toc.length > opts.minEntries) {
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file.data.toc = toc.map((entry) => ({
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...entry,
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depth: entry.depth - highestDepth,
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}))
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file.data.collapseToc = opts.collapseByDefault
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}
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}
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}
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},
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]
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},
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}
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}
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declare module "vfile" {
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interface DataMap {
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toc: TocEntry[]
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collapseToc: boolean
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}
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}
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