hexo——从命令行到代码

前言

hexo init和hexo new|server .etc是如何从命令行执行到对应的代码的，

通过下面的步骤将会有所了解

步骤讲解

npm安装hexo-cli

npm install -g hexo-cli

安装完之后，会在npm的安装路径下面有如下内容生成

上面图片中红框的内容保证了我们可以在命令行中执行hexo 命令

hexo init调用链

命令行执行hexo之后会调用，当前目录下的node_modules下面的hexo-cli模块对应脚本

这个脚本最终会执行对应目录的hexo.js脚本

// cmd是我们传入的命令参数
function entry(cwd = process.cwd(), args) {
  args = camelCaseKeys(args || minimist(process.argv.slice(2), { string: ['_', 'p', 'path', 's', 'slug'] }));

  let hexo = new Context(cwd, args);
  let { log } = hexo;

  // Change the title in console
  process.title = 'hexo';

  function handleError(err) {
    if (err && !(err instanceof HexoNotFoundError)) {
      log.fatal(err);
    }

    process.exitCode = 2;
  }

  // 寻找有没有安装对应命令的模块，
  // 判断hexo-cli/package.json中是否有hexo的依赖，这里是"main": "dist/hexo"
    
  return findPkg(cwd, args).then(path => {
    if (!path) return;

    hexo.base_dir = path;

    // 加载hexo模块
    return loadModule(path, args).catch(err).then(mod => {
    if (mod) hexo = mod;
    log = hexo.log;
	// 注册hexo命令行命令
    registerConsole(hexo);
    return hexo.init();
  }).then(() => {
    let cmd = 'help';

    if (!args.h && !args.help) {
      const c = args._.shift();
      if (c && hexo.extend.console.get(c)) cmd = c;
    }

    watchSignal(hexo);
	// 调用hexo命令
    // hexo init
    return hexo.call(cmd, args).then(() => hexo.exit()).catch(err);
}

*这里loadModule函数加载的hexo仍然是hexo-cli/bin/hexo*(可以看下package.json下面的hexo配置)，主要的目的是调用registerConsole函数注册hexo可以调用的命令 init/help|version **

// 同样，找的ts代码
// https://github.com/hexojs/hexo-cli/blob/master/lib/console/index.ts
export = function (ctx: Context) {
  const { console } = ctx.extend;

  console.register('help', 'Get help on a command.', {}, helpConsole);

  console.register('init', 'Create a new Hexo folder.', {
    desc: 'Create a new Hexo folder at the specified path or the current directory.',
    usage: '[destination]',
    arguments: [
      { name: 'destination', desc: 'Folder path. Initialize in current folder if not specified' }
    ],
    options: [
      { name: '--no-clone', desc: 'Copy files instead of cloning from GitHub' },
      { name: '--no-install', desc: 'Skip npm install' }
    ]
  }, initConsole);

  console.register('version', 'Display version information.', {}, versionConsole);
};

对应命令的实现也在console目录下。

不带参数(参数错误)执行结果如下：

hexo new调用链

*hexo new命令在*hexo init之后可以执行，同样，找node_modules目录下hexo-cli里面的 hexo脚本，同样是注册命令行命令然后执行对应的cmd，只不过注册命令函数有变化。**

// 初始化函数
// ts源码路径
// https://github.com/hexojs/hexo/blob/master/lib/hexo/index.ts
init(): Promise<void> {
  this.log.debug('Hexo version: %s', magenta(this.version));
  this.log.debug('Working directory: %s', magenta(tildify(this.base_dir)));

  // Load internal plugins
  require('../plugins/console')(this); // 这里的console里面注册了所有需要的内置命令
  require('../plugins/filter')(this);
  require('../plugins/generator')(this);
  require('../plugins/helper')(this);
  require('../plugins/highlight')(this);
  require('../plugins/injector')(this);
  require('../plugins/processor')(this);
  require('../plugins/renderer')(this);
  require('../plugins/tag').default(this);

  // Load config
  return Promise.each([
    'update_package', // Update package.json
    'load_config', // Load config
    'load_theme_config', // Load alternate theme config
    'load_plugins' // Load external plugins & scripts 加载我们外部定义的脚本和插件
  ], name => require(`./${name}`)(this)).then(() => this.execFilter('after_init', null, { context: this })).then(() => {
    // Ready to go!
    this.emit('ready');
  });
}

../plugins/console内容如下：

import type Hexo from '../../hexo';

// 源码路径：https://github.com/hexojs/hexo/blob/master/lib/plugins/console/index.ts
export = function (ctx: Hexo) {
  const { console } = ctx.extend;

  console.register('clean', 'Remove generated files and cache.', require('./clean'));

  console.register('config', 'Get or set configurations.', {
    usage: '[name] [value]',
    arguments: [
      { name: 'name', desc: 'Setting name. Leave it blank if you want to show all configurations.' },
      { name: 'value', desc: 'New value of a setting. Leave it blank if you just want to show a single configuration.' }
    ]
  }, require('./config'));

  console.register('deploy', 'Deploy your website.', {
    options: [
      { name: '--setup', desc: 'Setup without deployment' },
      { name: '-g, --generate', desc: 'Generate before deployment' }
    ]
  }, require('./deploy'));

  console.register('generate', 'Generate static files.', {
    options: [
      { name: '-d, --deploy', desc: 'Deploy after generated' },
      { name: '-f, --force', desc: 'Force regenerate' },
      { name: '-w, --watch', desc: 'Watch file changes' },
      { name: '-b, --bail', desc: 'Raise an error if any unhandled exception is thrown during generation' },
      { name: '-c, --concurrency', desc: 'Maximum number of files to be generated in parallel. Default is infinity' }
    ]
  }, require('./generate'));

  console.register('list', 'List the information of the site', {
    desc: 'List the information of the site.',
    usage: '<type>',
    arguments: [
      { name: 'type', desc: 'Available types: page, post, route, tag, category' }
    ]
  }, require('./list'));

  console.register('migrate', 'Migrate your site from other system to Hexo.', {
    init: true,
    usage: '<type>',
    arguments: [
      { name: 'type', desc: 'Migrator type.' }
    ]
  }, require('./migrate'));

  console.register('new', 'Create a new post.', {
    usage: '[layout] <title>',
    arguments: [
      { name: 'layout', desc: 'Post layout. Use post, page, draft or whatever you want.' },
      { name: 'title', desc: 'Post title. Wrap it with quotations to escape.' }
    ],
    options: [
      { name: '-r, --replace', desc: 'Replace the current post if existed.' },
      { name: '-s, --slug', desc: 'Post slug. Customize the URL of the post.' },
      { name: '-p, --path', desc: 'Post path. Customize the path of the post.' }
    ]
  }, require('./new'));

  console.register('publish', 'Moves a draft post from _drafts to _posts folder.', {
    usage: '[layout] <filename>',
    arguments: [
      { name: 'layout', desc: 'Post layout. Use post, page, draft or whatever you want.' },
      { name: 'filename', desc: 'Draft filename. "hello-world" for example.' }
    ]
  }, require('./publish'));

  console.register('render', 'Render files with renderer plugins.', {
    init: true,
    desc: 'Render files with renderer plugins (e.g. Markdown) and save them at the specified path.',
    usage: '<file1> [file2] ...',
    options: [
      { name: '--output', desc: 'Output destination. Result will be printed in the terminal if the output destination is not set.' },
      { name: '--engine', desc: 'Specify render engine' },
      { name: '--pretty', desc: 'Prettify JSON output' }
    ]
  }, require('./render'));
}

总体的简易流程图是这样的：