build: add pagetree build, build guide pagetree

lib/buildPageTree.js

@@ -0,0 +1,112 @@
+const fs = require("fs");
+const path = require("path");
+const matter = require("gray-matter");
+const toml = require("@iarna/toml");
+
+// node ./buildPageTree.js [directory] [sort]
+// eg. node ./buildPageTree docs weight
+// will produce docs.json in the cache folder.
+
+const options = {
+  engines: {
+    toml: toml.parse.bind(toml),
+  },
+  language: "toml",
+  delimiters: "+++",
+};
+
+/**
+ * buildPageTree is written to provide a recursive index of posts
+ * for nested directories for creating sidebars
+ * @param {string} path Absolute path to the subdirectory.
+ * @returns {Object.<string,string|Object<string,string[]|number>>} Title of the directory, child pages, and child directories (recursive structure).
+ *
+ */
+
+// type PageTree =
+//   { title: string,
+//     pages: [{
+//       title: string,
+//       base: string,
+//       slug: string,
+//       weight: number,
+//     }],
+//     children: { [string]: PageTree },
+//   }
+
+function buildPageTree(dirPath, ordering = "", content = false) {
+  const metadata = matter(
+    fs.readFileSync(path.join(dirPath, "_index.md")),
+    options
+  );
+  // get a list of contents at the dirPath, with file types so that the item at the dirPath can be identified as file or folder
+  const children = fs.readdirSync(dirPath, { withFileTypes: true });
+  // get a list of files
+  const pages = children.filter((f) => f.isFile() && f.name !== "_index.md");
+  // get a list of folders
+  const subdirs = children.filter((f) => f.isDirectory());
+  // return a pagetree datastructure
+  return {
+    ...metadata.data,
+    title: metadata.data.title,
+    pages: pages
+      .map((page) => {
+        // retrieve topmatter as JSON
+        const { content, data } = matter(
+          fs.readFileSync(path.join(dirPath, page.name)),
+          options
+        );
+
+        return {
+          ...data,
+          title: data.title,
+          base: page.name,
+          slug: page.name.replace(/.md$/, ""),
+          ...(ordering === "weight" && { weight: data?.weight ?? 0 }),
+          ...(ordering === "date" && {
+            date: data?.date ?? "2000-01-01T00:00:00.000Z",
+          }),
+        };
+      })
+      .sort((a, b) => a.weight - b.weight),
+    children: Object.fromEntries(
+      subdirs
+        .sort((a, b) => {
+          const aMetadata = matter(
+            fs.readFileSync(path.join(dirPath, a.name, "_index.md")),
+            options
+          );
+          const bMetadata = matter(
+            fs.readFileSync(path.join(dirPath, b.name, "_index.md")),
+            options
+          );
+          return aMetadata?.data?.weight - bMetadata?.data?.weight || 0;
+        })
+        .map((subdir) => [
+          subdir.name,
+          buildPageTree(path.join(dirPath, subdir.name), ordering, content),
+        ])
+    ),
+  };
+}
+
+const process = require("process");
+
+const arg = process.argv?.[2];
+const sort = process?.argv?.[3] || "weight";
+
+const dir = buildPageTree(path.join(process.cwd(), `content/${arg}`), sort);
+const fileContents = `${JSON.stringify(dir)}`;
+
+try {
+  fs.readdirSync("cache");
+} catch (err) {
+  fs.mkdirSync("cache");
+}
+
+fs.writeFile(`cache/${arg}.json`, fileContents, function (err) {
+  if (err) return console.error(err);
+  console.log(`${arg} directory structure created.`);
+});
+
+module.exports = { buildPageTree };

package.json

@@ -4,8 +4,9 @@
   "private": true,
   "scripts": {
     "dev": "npm run prebuild && next dev",
-    "prebuild": "npm run cache-posts",
+    "prebuild": "npm run cache-posts && npm run guide",
     "cache-posts": "node lib/cache.js",
+    "guide": "node lib/buildPageTree guides weight",
     "build": "next build",
     "start": "next start",
     "lint": "next lint"