parsemarkdown/src/utils/parser.ts

A parser for markdown files.

// const fs = require("fs");
import * as fs from "fs";
import * as mkdirp from "mkdirp";
import * as path from "path";
import * as yaml from "js-yaml";
import * as utils from "./index";

/**
 *
 *
 * @export 防抖动算法，参考: https://davidwalsh.name/function-debounce
 * @param {*} func
 * @param {number} wait
 * @param {boolean} immediate
 * @returns
 */
export function debounce(func: any, wait: number, immediate: boolean) {
  let timeout: any;
  return function() {
    let context = this;
    let args = arguments;
    let later = function() {
      timeout = null;
      if (!immediate) func.apply(context, args);
    };
    let callNow = immediate && !timeout;
    clearTimeout(timeout);
    timeout = setTimeout(later, wait);
    if (callNow) func.apply(context, args);
  };
}

/**
 *
 *
 * @export 读取文件内容之前，先保证这是一个文件
 * @param {string} file
 * @param {*} cb
 * @returns {void}
 */
export function readFileContent(file: string, cb: any): void {
  if (!file || fs.lstatSync(file).isDirectory()) {
    return null;
  }
  fs.readFile(file, (err: any, data: any) => {
    cb(err, file, data && data.toString());
  });
}

/**
 *
 *
 * @export 写入文件内容之前，先保证这是一个文件
 * @param {string} file
 * @param {string} content
 * @param {*} cb
 */
export function writeFileContent(file: string, content: string, cb: any) {
  mkdirp(path.dirname(file), function(err: any) {
    if (err) throw err;
    fs.writeFile(file, content, (e: any) => {
      cb(e);
    });
  });
}

/**
 *
 *
 * @export 解析markdown文件
 * @param {string} file
 * @returns
 */
export function parseMarkdown(file: string) {
  let obj = {};
  try {
    const fileContent = fs.readFileSync(file, "utf8");

    const splitContent = fileContent.match(/^-{3}[\s\S]+?-{3}/);

    const frontmatter = yaml.safeLoad(
      splitContent[0].substring(3, splitContent[0].length - 3)
    );

    const content = fileContent.substring(splitContent[0].length).trim();
    let previewMatch = content.match(/[\s\S]+?(<!-- more -->)/);
    let preview =
      previewMatch === null
        ? ""
        : previewMatch[0].substring(
            0,
            previewMatch[0].length - "<!-- more -->".length
          );

    // 日期格式处理，默认情况下显示时间提前8小时
    let createAt = frontmatter.createAt;
    let createAtFormat = new Date(createAt).getTime() - 1000 * 60 * 60 * 8;
    createAt = utils.formatDateTime(createAtFormat);

    let updateAt = frontmatter.updateAt;
    let updateAtFormat = new Date(updateAt).getTime() - 1000 * 60 * 60 * 8;
    updateAt = utils.formatDateTime(updateAtFormat);

    obj = { ...frontmatter, ...{ content, preview }, createAt, updateAt };

    // console.log("preview", preview);
  } catch (error) {
    console.log(error);
  }
  return obj;
}

/**
 *
 *
 * @export 处理目录字符串。示例："/post////"=> "/post"
 * @param {string} dir
 * @returns {string}
 */
export function dirnameTrim(dir: string): string {
  if (dir[dir.length - 1] === "/") {
    dir = dir.slice(0, dir.length - 1);
    return dirnameTrim(dir);
  } else {
    return dir;
  }
}