hexo new命令解析

hexo new命令

hexo new命令是创建新文章的，后面跟文章的名字比如hexo new helloworld,那么就会创建一篇title为helloworld的文章。

var cmd = '';

  if (!args.h && !args.help) {
    cmd = args._.shift();

    if (cmd) {
      var c = hexo.extend.console.get(cmd);
      if (!c) cmd = 'help';
    } else {
      cmd = 'help';
    }
  } else {
    cmd = 'help';
  }

args对象类似{ _: [ 'n', 'hexo_new' ] }这种形式，所以args._.shift()得到的结果是n。

hexo.extend.console.get是通过定义extend对象，extend对象中定义console对象：
代码在hexo目录index.js文件中：

头部先require入extend文件

var extend = require('../extend');

../extend默认会引入extend目录下的index.js文件：

'use strict';

exports.Console = require('./console');
exports.Deployer = require('./deployer');
exports.Filter = require('./filter');
exports.Generator = require('./generator');
exports.Helper = require('./helper');
exports.Migrator = require('./migrator');
exports.Processor = require('./processor');
exports.Renderer = require('./renderer');
exports.Tag = require('./tag');

require('./console')引入同级目录下的console文件：

   ...部分代码省略
Console.prototype.get = function(name){
	  name = name.toLowerCase();
	  return this.store[this.alias[name]];
};
...部分代码省略

随后在Hexo构造函数中定义：

this.extend = {
   console: new extend.Console(),
   deployer: new extend.Deployer(),
   filter: new extend.Filter(),
   generator: new extend.Generator(),
   helper: new extend.Helper(),
   migrator: new extend.Migrator(),
   processor: new extend.Processor(),
   renderer: new extend.Renderer(),
   tag: new extend.Tag()
 };

所以我们看到了hexo.extend.console.get的流程，既然是获取，那么肯定有注册的过程

注册时在hexo.init()的时候注册的

  ...hexo_cli/lib/hexo.js中 找到hexo模块后调用此方法,部分代码省略
function(mod) {
   if (mod) hexo = mod;
   log = hexo.log;

   require('./console')(hexo);

   return hexo.init();
 }

Hexo.prototype.init = function(){
  var self = this;

  this.log.debug('Hexo version: %s', chalk.magenta(this.version));
  this.log.debug('Working directory: %s', chalk.magenta(tildify(this.base_dir)));

  // Load internal plugins
  //加载内部插件
  require('../plugins/console')(this);
}

plugins/console/index.js部分代码如下：

//先获取在构造函数中定义的console对象
 var console = ctx.extend.console;

 ...部分代码省略
 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.prototype.register = function(name, desc, options, fn){
	  if (!name) throw new TypeError('name is required');

	  if (!fn){
	    if (options){
	      if (typeof options === 'function'){
	        fn = options;

	        if (typeof desc === 'object'){ // name, options, fn
	          options = desc;
	          desc = '';
	        } else { // name, desc, fn
	          options = {};
	        }
	      } else {
	        throw new TypeError('fn must be a function');
	      }
	    } else {
	      // name, fn
	      if (typeof desc === 'function'){
	        fn = desc;
	        options = {};
	        desc = '';
	      } else {
	        throw new TypeError('fn must be a function');
	      }
	    }
	  }

	  if (fn.length > 1){
	    fn = Promise.promisify(fn);
	  } else {
	    fn = Promise.method(fn);
	  }

	  var c = this.store[name.toLowerCase()] = fn;
	  c.options = options;
	  c.desc = desc;
	  //new 变成n ne
	  this.alias = abbrev(Object.keys(this.store));
}

我们看看执行new的函数：

function newConsole(args){
	  /* jshint validthis: true */
	  // Display help message if user didn't input any arguments
	  if (!args._.length){
	    return this.call('help', {_: ['new']});
	    //控制台打出类似`Usage: hexo new [layout] <title>`
	  }

	  var data = {
	    title: args._.pop(),
	    layout: args._.length ? args._[0] : this.config.default_layout,
	    slug: args.s || args.slug,
	    path: args.p || args.path
	  };

	  var keys = Object.keys(args);
	  var key = '';
	  var self = this;

	  for (var i = 0, len = keys.length; i < len; i++){
	    key = keys[i];
	    if (!reservedKeys[key]) data[key] = args[key];
	  }

	  return this.post.create(data, args.r || args.replace).then(function(post){
	    self.log.info('Created: %s', chalk.magenta(tildify(post.path)));
	  });
}