Initial commit

quartz/plugins/transformers/links.ts

@@ -0,0 +1,171 @@
+import { QuartzTransformerPlugin } from "../types"
+import {
+  FullSlug,
+  RelativeURL,
+  SimpleSlug,
+  TransformOptions,
+  stripSlashes,
+  simplifySlug,
+  splitAnchor,
+  transformLink,
+  joinSegments,
+} from "../../util/path"
+import path from "path"
+import { visit } from "unist-util-visit"
+import isAbsoluteUrl from "is-absolute-url"
+import { Root } from "hast"
+
+interface Options {
+  /** How to resolve Markdown paths */
+  markdownLinkResolution: TransformOptions["strategy"]
+  /** Strips folders from a link so that it looks nice */
+  prettyLinks: boolean
+  openLinksInNewTab: boolean
+  lazyLoad: boolean
+  externalLinkIcon: boolean
+}
+
+const defaultOptions: Options = {
+  markdownLinkResolution: "absolute",
+  prettyLinks: true,
+  openLinksInNewTab: false,
+  lazyLoad: false,
+  externalLinkIcon: true,
+}
+
+export const CrawlLinks: QuartzTransformerPlugin<Partial<Options> | undefined> = (userOpts) => {
+  const opts = { ...defaultOptions, ...userOpts }
+  return {
+    name: "LinkProcessing",
+    htmlPlugins(ctx) {
+      return [
+        () => {
+          return (tree: Root, file) => {
+            const curSlug = simplifySlug(file.data.slug!)
+            const outgoing: Set<SimpleSlug> = new Set()
+
+            const transformOptions: TransformOptions = {
+              strategy: opts.markdownLinkResolution,
+              allSlugs: ctx.allSlugs,
+            }
+
+            visit(tree, "element", (node, _index, _parent) => {
+              // rewrite all links
+              if (
+                node.tagName === "a" &&
+                node.properties &&
+                typeof node.properties.href === "string"
+              ) {
+                let dest = node.properties.href as RelativeURL
+                const classes = (node.properties.className ?? []) as string[]
+                const isExternal = isAbsoluteUrl(dest)
+                classes.push(isExternal ? "external" : "internal")
+
+                if (isExternal && opts.externalLinkIcon) {
+                  node.children.push({
+                    type: "element",
+                    tagName: "svg",
+                    properties: {
+                      class: "external-icon",
+                      viewBox: "0 0 512 512",
+                    },
+                    children: [
+                      {
+                        type: "element",
+                        tagName: "path",
+                        properties: {
+                          d: "M320 0H288V64h32 82.7L201.4 265.4 178.7 288 224 333.3l22.6-22.6L448 109.3V192v32h64V192 32 0H480 320zM32 32H0V64 480v32H32 456h32V480 352 320H424v32 96H64V96h96 32V32H160 32z",
+                        },
+                        children: [],
+                      },
+                    ],
+                  })
+                }
+
+                // Check if the link has alias text
+                if (
+                  node.children.length === 1 &&
+                  node.children[0].type === "text" &&
+                  node.children[0].value !== dest
+                ) {
+                  // Add the 'alias' class if the text content is not the same as the href
+                  classes.push("alias")
+                }
+                node.properties.className = classes
+
+                if (opts.openLinksInNewTab) {
+                  node.properties.target = "_blank"
+                }
+
+                // don't process external links or intra-document anchors
+                const isInternal = !(isAbsoluteUrl(dest) || dest.startsWith("#"))
+                if (isInternal) {
+                  dest = node.properties.href = transformLink(
+                    file.data.slug!,
+                    dest,
+                    transformOptions,
+                  )
+
+                  // url.resolve is considered legacy
+                  // WHATWG equivalent https://nodejs.dev/en/api/v18/url/#urlresolvefrom-to
+                  const url = new URL(dest, "https://base.com/" + stripSlashes(curSlug, true))
+                  const canonicalDest = url.pathname
+                  let [destCanonical, _destAnchor] = splitAnchor(canonicalDest)
+                  if (destCanonical.endsWith("/")) {
+                    destCanonical += "index"
+                  }
+
+                  // need to decodeURIComponent here as WHATWG URL percent-encodes everything
+                  const full = decodeURIComponent(stripSlashes(destCanonical, true)) as FullSlug
+                  const simple = simplifySlug(full)
+                  outgoing.add(simple)
+                  node.properties["data-slug"] = full
+                }
+
+                // rewrite link internals if prettylinks is on
+                if (
+                  opts.prettyLinks &&
+                  isInternal &&
+                  node.children.length === 1 &&
+                  node.children[0].type === "text" &&
+                  !node.children[0].value.startsWith("#")
+                ) {
+                  node.children[0].value = path.basename(node.children[0].value)
+                }
+              }
+
+              // transform all other resources that may use links
+              if (
+                ["img", "video", "audio", "iframe"].includes(node.tagName) &&
+                node.properties &&
+                typeof node.properties.src === "string"
+              ) {
+                if (opts.lazyLoad) {
+                  node.properties.loading = "lazy"
+                }
+
+                if (!isAbsoluteUrl(node.properties.src)) {
+                  let dest = node.properties.src as RelativeURL
+                  dest = node.properties.src = transformLink(
+                    file.data.slug!,
+                    dest,
+                    transformOptions,
+                  )
+                  node.properties.src = dest
+                }
+              }
+            })
+
+            file.data.links = [...outgoing]
+          }
+        },
+      ]
+    },
+  }
+}
+
+declare module "vfile" {
+  interface DataMap {
+    links: SimpleSlug[]
+  }
+}