refactor(v2): plugin, utils as separate package (#1298)

* refactor(v2): plugin, utils as separate package

* rename docusaurus-plugin to @docusaurus/plugin

* update snapshot

packages/docusaurus-plugin-content-blog/index.js

@@ -0,0 +1,141 @@
+/**
+ * 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');
+const {parse, idx, normalizeUrl} = require('@docusaurus/utils');
+
+function fileToUrl(fileName) {
+  return fileName
+    .replace('-', '/')
+    .replace('-', '/')
+    .replace('-', '/')
+    .replace(/\.md$/, '');
+}
+
+const DEFAULT_OPTIONS = {
+  metadataKey: 'blogMetadata',
+  metadataFileName: 'blogMetadata.json',
+  path: 'blog', // Path to data on filesystem.
+  routeBasePath: 'blog', // URL Route.
+  include: ['*.md, *.mdx'], // Extensions to include.
+  pageCount: 10, // How many entries per page.
+  blogPageComponent: '@theme/BlogPage',
+  blogPostComponent: '@theme/BlogPost',
+};
+
+class DocusaurusPluginContentBlog {
+  constructor(opts, context) {
+    this.options = {...DEFAULT_OPTIONS, ...opts};
+    this.context = context;
+    this.contentPath = path.resolve(this.context.siteDir, this.options.path);
+  }
+
+  getName() {
+    return 'docusaurus-plugin-content-blog';
+  }
+
+  // Fetches blog contents and returns metadata for the contents.
+  async loadContents() {
+    const {pageCount, include, routeBasePath} = this.options;
+    const {env, siteConfig} = this.context;
+    const blogDir = this.contentPath;
+
+    const {baseUrl} = siteConfig;
+    const blogFiles = await globby(include, {
+      cwd: blogDir,
+    });
+
+    // Prepare metadata container.
+    const blogMetadata = [];
+
+    // Language for each blog page.
+    const defaultLangTag = idx(env, ['translation', 'defaultLanguage', 'tag']);
+
+    await Promise.all(
+      blogFiles.map(async relativeSource => {
+        const source = path.join(blogDir, relativeSource);
+
+        const blogFileName = path.basename(relativeSource);
+        // Extract, YYYY, MM, DD from the file name.
+        const filePathDateArr = blogFileName.split('-');
+        const date = new Date(
+          `${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 blogMetadata;
+  }
+
+  async generateRoutes({metadata, actions}) {
+    const {blogPageComponent, blogPostComponent} = this.options;
+    const {addRoute} = actions;
+    metadata.forEach(metadataItem => {
+      const {isBlogPage, permalink} = metadataItem;
+      if (isBlogPage) {
+        addRoute({
+          path: permalink,
+          component: blogPageComponent,
+          metadata: metadataItem,
+          modules: metadataItem.posts.map(post => post.source),
+        });
+        return;
+      }
+
+      addRoute({
+        path: permalink,
+        component: blogPostComponent,
+        metadata: metadataItem,
+        modules: [metadataItem.source],
+      });
+    });
+  }
+
+  getPathsToWatch() {
+    return [this.contentPath];
+  }
+}
+
+module.exports = DocusaurusPluginContentBlog;