From 405f6f510386825040a6f50526aaf9b026a2dd74 Mon Sep 17 00:00:00 2001
From: Thomas Hack <thomas.hack9@gmail.com>
Date: Thu, 15 Aug 2024 15:48:14 +0200
Subject: [PATCH] feat: add subfolders to folder page

---
 quartz/components/FolderList.tsx          | 38 +++++++++++++++++++++
 quartz/components/pages/FolderContent.tsx | 41 ++++++++++++++++++++---
 2 files changed, 74 insertions(+), 5 deletions(-)
 create mode 100644 quartz/components/FolderList.tsx

diff --git a/quartz/components/FolderList.tsx b/quartz/components/FolderList.tsx
new file mode 100644
index 000000000..7a81e2600
--- /dev/null
+++ b/quartz/components/FolderList.tsx
@@ -0,0 +1,38 @@
+import path from "path"
+import { resolveRelative, SimpleSlug } from "../util/path"
+import { QuartzComponent, QuartzComponentProps } from "./types"
+
+type Props = {
+  limit?: number
+} & QuartzComponentProps
+
+export const FolderList: QuartzComponent = ({ cfg, fileData, allFolders, limit }: Props) => {
+  let list: SimpleSlug[] = allFolders.sort(_alphabetical)
+  if (limit) {
+    list = list.slice(0, limit)
+  }
+
+  return (
+    <ul>
+      {list.map((folderSlug) => {
+        const title = _getTitle(folderSlug)
+
+        return (
+          <li>
+            <a href={resolveRelative(fileData.slug!, folderSlug!)}>{title}</a>
+          </li>
+        )
+      })}
+    </ul>
+  )
+}
+
+function _alphabetical(f1: SimpleSlug, f2: SimpleSlug): number {
+  const f1Title = _getTitle(f1)
+  const f2Title = _getTitle(f2)
+  return f1Title.localeCompare(f2Title)
+}
+
+function _getTitle(folderSlug: SimpleSlug): string {
+  return folderSlug.split(path.posix.sep).at(-1)!
+}
diff --git a/quartz/components/pages/FolderContent.tsx b/quartz/components/pages/FolderContent.tsx
index dc216cde7..90f981f1e 100644
--- a/quartz/components/pages/FolderContent.tsx
+++ b/quartz/components/pages/FolderContent.tsx
@@ -3,21 +3,25 @@ import path from "path"
 
 import style from "../styles/listPage.scss"
 import { PageList, SortFn } from "../PageList"
-import { stripSlashes, simplifySlug } from "../../util/path"
+import { FolderList } from "../FolderList"
+import { stripSlashes, simplifySlug, SimpleSlug, joinSegments } from "../../util/path"
 import { Root } from "hast"
 import { htmlToJsx } from "../../util/jsx"
 import { i18n } from "../../i18n"
+import { QuartzPluginData } from "../../plugins/vfile"
 
 interface FolderContentOptions {
   /**
    * Whether to display number of folders
    */
   showFolderCount: boolean
+  showSubfolders: boolean
   sort?: SortFn
 }
 
 const defaultOptions: FolderContentOptions = {
   showFolderCount: true,
+  showSubfolders: true,
 }
 
 export default ((opts?: Partial<FolderContentOptions>) => {
@@ -26,21 +30,40 @@ export default ((opts?: Partial<FolderContentOptions>) => {
   const FolderContent: QuartzComponent = (props: QuartzComponentProps) => {
     const { tree, fileData, allFiles, cfg } = props
     const folderSlug = stripSlashes(simplifySlug(fileData.slug!))
-    const allPagesInFolder = allFiles.filter((file) => {
+
+    const allPagesInFolder: QuartzPluginData[] = []
+    const allSubfolders: Set<SimpleSlug> = new Set()
+
+    allFiles.forEach((file) => {
       const fileSlug = stripSlashes(simplifySlug(file.slug!))
       const prefixed = fileSlug.startsWith(folderSlug) && fileSlug !== folderSlug
       const folderParts = folderSlug.split(path.posix.sep)
       const fileParts = fileSlug.split(path.posix.sep)
       const isDirectChild = fileParts.length === folderParts.length + 1
-      return prefixed && isDirectChild
+
+      if (!prefixed) {
+        return
+      }
+
+      if (isDirectChild) {
+        allPagesInFolder.push(file)
+      } else {
+        const folderSlug = joinSegments(...fileParts.slice(0, folderParts.length + 1))
+        allSubfolders.add(folderSlug as SimpleSlug)
+      }
     })
+
     const cssClasses: string[] = fileData.frontmatter?.cssclasses ?? []
     const classes = ["popover-hint", ...cssClasses].join(" ")
-    const listProps = {
+    const pageListProps = {
       ...props,
       sort: options.sort,
       allFiles: allPagesInFolder,
     }
+    const folderListProps = {
+      ...props,
+      allFolders: Array.from(allSubfolders.values()),
+    }
 
     const content =
       (tree as Root).children.length === 0
@@ -59,7 +82,15 @@ export default ((opts?: Partial<FolderContentOptions>) => {
             </p>
           )}
           <div>
-            <PageList {...listProps} />
+            <PageList {...pageListProps} />
+          </div>
+        </div>
+        <div class="page-listing">
+          {options.showSubfolders && (
+            <p>{allSubfolders.size === 1 ? "1 subfolder." : `${allSubfolders.size} subfolders.`}</p>
+          )}
+          <div>
+            <FolderList {...folderListProps} />
           </div>
         </div>
       </div>