feat(v2): create docusaurus-content-blog plugin draft

v2/plugins/docusaurus-content-blog.js

@@ -0,0 +1,106 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+const globby = require('globby');
+const path = require('path');
+const fs = require('fs-extra');
+// TODO: Do not make it relative because plugins can be from node_modules.
+const {parse, idx, normalizeUrl} = require('../lib/load/utils');
+
+function fileToUrl(fileName) {
+  return fileName
+    .replace('-', '/')
+    .replace('-', '/')
+    .replace('-', '/')
+    .replace(/\.md$/, '');
+}
+
+const DEFAULT_OPTIONS = {
+  contentKey: 'blog',
+  path: 'blog', // Path to data on filesystem.
+  routeBasePath: 'blog', // URL Route.
+  include: ['*.md'], // Extensions to include.
+  pageCount: 10, // How many entries per page.
+  cachePath: 'blogMetadata.js',
+};
+
+async function onLoadContent(opts, context) {
+  const options = {...DEFAULT_OPTIONS, ...opts};
+
+  const {env, siteConfig, siteDir} = context;
+  const {pageCount, path: filePath, routeBasePath} = options;
+  const blogDir = path.resolve(siteDir, filePath);
+  const {baseUrl} = siteConfig;
+
+  const blogFiles = await globby(options.include, {
+    cwd: blogDir,
+  });
+
+  // Prepare metadata container.
+  const blogMetadata = [];
+
+  // Language for each blog page.
+  const defaultLangTag = idx(env, ['translation', 'defaultLanguage', 'tag']);
+
+  await Promise.all(
+    blogFiles.map(async relativeSource => {
+      const source = path.join(blogDir, relativeSource);
+
+      const blogFileName = path.basename(relativeSource);
+      // Extract, YYYY, MM, DD from the file name.
+      const filePathDateArr = blogFileName.split('-');
+      const date = new Date(
+        `${filePathDateArr[0]}-${filePathDateArr[1]}-${
+          filePathDateArr[2]
+        }T06:00:00.000Z`,
+      );
+
+      const fileString = await fs.readFile(source, 'utf-8');
+      const {metadata: rawMetadata} = parse(fileString);
+      const metadata = {
+        permalink: normalizeUrl([
+          baseUrl,
+          routeBasePath,
+          fileToUrl(blogFileName),
+        ]),
+        source,
+        ...rawMetadata,
+        date,
+        language: defaultLangTag,
+      };
+      blogMetadata.push(metadata);
+    }),
+  );
+  blogMetadata.sort((a, b) => a.date - b.date);
+
+  // Blog page handling. Example: `/blog`, `/blog/page1`, `/blog/page2`
+  const numOfBlog = blogMetadata.length;
+  const numberOfPage = Math.ceil(numOfBlog / pageCount);
+  const basePageUrl = path.join(baseUrl, routeBasePath);
+
+  // eslint-disable-next-line
+  for (let page = 0; page < numberOfPage; page++) {
+    blogMetadata.push({
+      permalink: normalizeUrl([
+        basePageUrl,
+        `${page > 0 ? `page${page + 1}` : ''}`,
+      ]),
+      language: defaultLangTag,
+      isBlogPage: true,
+      posts: blogMetadata.slice(page * pageCount, (page + 1) * pageCount),
+    });
+  }
+
+  return {
+    contents: blogMetadata,
+    options,
+  };
+}
+
+module.exports = {
+  onLoadContent,
+};