docusaurus/v2/plugins/docusaurus-content-blog.js

/**
 * 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.
  cacheFileName: 'blogMetadata.json',
  blogPageComponent: '@theme/BlogPage',
  blogPostComponent: '@theme/BlogPost',
};

class DocusaurusContentBlogPlugin {
  constructor(opts, context) {
    this.options = {...DEFAULT_OPTIONS, ...opts};
    this.context = context;
  }

  async loadContents() {
    const {pageCount, path: filePath, include, routeBasePath} = this.options;
    const {env, siteConfig, siteDir} = this.context;
    const blogDir = path.resolve(siteDir, filePath);
    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({contents, actions}) {
    const {blogPostComponent} = this.options;
    const {addRoute} = actions;
    contents.forEach(metadata => {
      const {permalink, source} = metadata;
      if (metadata.isBlogPage) {
        // TODO: Handle blog page.
        return;
      }

      addRoute({
        path: permalink,
        component: blogPostComponent,
        metadata,
        content: source,
      });
    });
  }
}

module.exports = DocusaurusContentBlogPlugin;