john's tech blog

hexo_postname

发表于 2016-09-18 | 更新于 2019-05-07

new_post_path.js

hexo的文章生成名称经过newPostFilter这个过滤器来生成的：

ctx.execFilter('new_post_path', data, {
     args: [replace],
     context: ctx
   })

function newPostPathFilter(data, replace){
  /* jshint validthis: true */
  data = data || {};//data里带有文章标题

  var sourceDir = this.source_dir;//this指向hexo实例
  //this.source_dir = pathFn.join(base, 'source') + sep; hexo/index.js
  var draftDir = pathFn.join(sourceDir, '_drafts');
  var postDir = pathFn.join(sourceDir, '_posts');
  var config = this.config;
  var newPostName = config.new_post_name;//默认为:title.md
  var permalinkDefaults = config.permalink_defaults;
  var path = data.path;//默认为空
  var layout = data.layout;//默认为空
  var slug = data.slug;//文章标题
  var target = '';

  if (!permalink || permalink.rule !== newPostName){
    permalink = new Permalink(newPostName); //固定链接 :title.md
  }

  if (path){
    switch (layout){
      case 'page':
        target = pathFn.join(sourceDir, path);
        break;

      case 'draft':
        target = pathFn.join(draftDir, path);
        break;

      default:
        target = pathFn.join(postDir, path);
    }
  } else if (slug){
    switch (layout){
      case 'page':
        target = pathFn.join(sourceDir, slug, 'index');
        break;

      case 'draft':
        target = pathFn.join(draftDir, slug);
        break;

      default:
        var date = moment(data.date || Date.now());//moment库
        var keys = Object.keys(data);
        var key = '';

        var filenameData = {
          year: date.format('YYYY'),
          month: date.format('MM'),
          i_month: date.format('M'),
          day: date.format('DD'),
          i_day: date.format('D'),
          title: slug
        };

        for (var i = 0, len = keys.length; i < len; i++){
          key = keys[i];
          if (!reservedKeys[key]) filenameData[key] = data[key];
        }
        //console.log('defaults:'+ _.defaults(filenameData, permalinkDefaults).title);
        //console.log('postDir:'+postDir);

        //permalink.stringify 正则替换把permalink中的title替换为filenamedata中的titile，就是文章标题
        //_.defaults lodash库
        //Assigns own enumerable properties of source object(s) to the destination object for all destination properties that resolve to undefined. Once a property is set, additional values of the same property are ignored.

        target = pathFn.join(postDir, permalink.stringify(
          _.defaults(filenameData, permalinkDefaults)));
    }
  } else {
    return Promise.reject(new TypeError('Either data.path or data.slug is required!'));
  }

  if (!pathFn.extname(target)){
    target += pathFn.extname(newPostName) || '.md';
  }

  if (replace){
    return Promise.resolve(target);
  } else {
    return fs.ensurePath(target);
  }
}

hexo-fs/lib/fs.js

function ensurePath(path, callback){
  if (!path) throw new TypeError('path is required!');

  return exists(path).then(function(exist){
    if (!exist) return path;

    return readdirAsync(dirname(path)).then(function(files){
      return _findUnusedPath(path, files);
    });
  }).nodeify(callback);
}

function exists(path, callback){
  if (!path) throw new TypeError('path is required!');

  return new Promise(function(resolve, reject){
    fs.exists(path, function(exist){
      resolve(exist);
      if (typeof callback === 'function') callback(exist);
    });
  });
}

最终文件名的秘密就在这里,相同的文件名就自动加上数字

_findUnusedPath

function _findUnusedPath(path, files){
  var extname = pathFn.extname(path);
  var basename = pathFn.basename(path, extname);
  var regex = new RegExp('^' + escapeRegExp(basename) + '(?:-(\\d+))?' + escapeRegExp(extname) + '$');
  var item = '';
  var num = -1;
  var match, matchNum;

  for (var i = 0, len = files.length; i < len; i++){
    item = files[i];
    if (!regex.test(item)) continue;

    match = item.match(regex);
    matchNum = match[1] ? parseInt(match[1], 10) : 0;

    if (matchNum > num){
      num = matchNum;
    }
  }

  return join(dirname(path), basename + '-' + (num + 1) + extname);
}

hexo_util工具包分析1

发表于 2016-09-15 | 更新于 2019-05-07

hexo util包分析

index.js

'use strict';

exports.escapeDiacritic = require('./escape_diacritic');
exports.escapeHTML = require('./escape_html');
exports.escapeRegExp = require('./escape_regexp');
exports.highlight = require('./highlight');
exports.htmlTag = require('./html_tag');
exports.Pattern = require('./pattern');
exports.Permalink = require('./permalink');
exports.slugize = require('./slugize');
exports.spawn = require('./spawn');
exports.stripHTML = require('./strip_html');
exports.truncate = require('./truncate');
exports.wordWrap = require('./word_wrap');

导出了这么多工具类，我们先看slugize，因为关系到post创建的过程

var ctx = this.context;
var config = ctx.config;
//文章标题
data.slug = slugize((data.slug || data.title).toString(), {transform: config.filename_case});
data.layout = (data.layout || config.default_layout).toLowerCase();
data.date = data.date ? moment(data.date) : moment();

'use strict';
//最重要的就是这两个函数escapeDiacritic和escapeRegExp
var escapeDiacritic = require('./escape_diacritic');
var escapeRegExp = require('./escape_regexp');
var rControl = /[\u0000-\u001f]/g;
var rSpecial = /[\s~`!@#\$%\^&\*\(\)\-_\+=\[\]\{\}\|\\;:"'<>,\.\?\/]+/g;

module.exports = function(str, options){
  if (typeof str !== 'string') throw new TypeError('str must be a string!');
  options = options || {};

  var separator = options.separator || '-';
  var escapedSep = escapeRegExp(separator);// 输出\-

  var result = escapeDiacritic(str)
    // Remove control characters
    .replace(rControl, '')
    // Replace special characters
    .replace(rSpecial, separator)
    // Remove continous separators
    .replace(new RegExp(escapedSep + '{2,}', 'g'), separator)
      //n是一个非负整数。至少匹配n次。例如，“o{2,}”不能匹配“Bob”中的“o”，但能匹配“foooood”中的所有o。“o{1,}”等价于“o+”。“o{0,}”则等价于“o*”。
    // Remove prefixing and trailing separtors
    .replace(new RegExp('^' + escapedSep + '+|' + escapedSep + '+$', 'g'), '');

  switch (options.transform){
    case 1:
      return result.toLowerCase();

    case 2:
      return result.toUpperCase();

    default:
      return result;
  }
};

bluebird的promiseall浅析

发表于 2016-09-14 | 更新于 2019-05-09

Promise.all

hexo中load方法使用了Promise.all,来看代码：

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

  return loadDatabase(this).then(function(){
    return Promise.all([
      self.source.process(),
      self.theme.process()
    ]);
  }).then(function(){
    return self._generate({cache: true});
    //只有当上面两个方法都执行成功后才会调用_
  }).nodeify(callback);
};

var Promise = require('bluebird');

var call = function(name, args, callback){
  if (!callback && typeof args === 'function'){
    callback = args;
    args = {};
  }

  return Promise.all([
      (function(){
         console.log('1');//这里会打印
         //var i = '5';
      })(),
      (function(){
         //console.log('2');//这里不会打印

         throw '2';
      })(),
      (function(){
         console.log('6');//这里不会打印
      })()
    ]).then(function(){//数组里的都通过才会打印3
    console.log('3');
  }).nodeify(callback);
};

 call('new', '2',function(e){
  console.log('nodeify');
 	console.log(e);
 	console.log('callback'); //进入reject会调用callback

  //throw ;
 }).then(function() {
      	console.log('then');
    }).catch(function(err) {
      console.log('end');
      console.log(err);//进入reject会调用
 });

bluebird Promise框架学习一

发表于 2016-09-13 | 更新于 2019-05-09

hexo中的Promise用了bluebird提供的，比如Promise.each,Promise.all,new Promise,Promise.map 等等。

Promise.each

var Promise = require('bluebird');

Promise.each([
    'update_package', // Update package.json
    'load_config', // Load config
    'load_plugins' // Load external plugins & scripts
  ], function(name){
     if(name == 'load_config')
     	throw 'error';
     console.log(name);//会输出update_package,其余不会输出
  }).catch(function(e){

  		console.log(e);
  });

var Promise = require('bluebird');

var call = function(name, args, callback){
  if (!callback && typeof args === 'function'){
    callback = args;
    args = {};
  }

 return new Promise(function(resolve, reject){
    var c = 1;

    if (!c){
       console.log('done');
    } else {
    	//进入reject
      reject(new Error('Console `` has not been registered yet!'));
    }
  }).nodeify(callback);
};

 call('new', '2',function(e){
 	console.log(e);
 	console.log('callback'); //进入reject会调用callback
 }).then(function() {
      	console.log('then');
    }).catch(function(err) {
      console.log(err);//进入reject会调用
 });

hexo post.create的过程分析

发表于 2016-09-11 | 更新于 2019-05-07

hexo的post创建过程

要讲hexo的post.create先要看它的传入参数。

1	this.post.create(data, args.r \|\| args.replace)

data定义如下：

var data = {
    title: args._.pop(),//标题
    //这里layout就是可以通过 hexo n  title layout获取
    layout: args._.length ? args._[0] : this.config.default_layout,
    slug: args.s || args.slug,//为undefined
    path: args.p || args.path//为undefined
  };

hexo/post.js：

Post.prototype.create = function(data, replace, callback){
  //callback没传入 replace 为undefined
  if (!callback && typeof replace === 'function'){
    callback = replace;
    replace = false;
  }

  var ctx = this.context;//为hexo对象
  var config = ctx.config; //_.clone(defaultConfig) _:lodash库 浅拷贝
  //https://github.com/lodash

  //slugize为hexo_util库中的函数
  data.slug = slugize((data.slug || data.title).toString(), {transform: config.filename_case});
  data.layout = (data.layout || config.default_layout).toLowerCase();
  data.date = data.date ? moment(data.date) : moment();//获取当前时间 moment库

  return Promise.all([
    // Get the post path
    ctx.execFilter('new_post_path', data, {
      args: [replace],
      context: ctx
    }),
    // Get the scaffold
    this._getScaffold(data.layout)
  ]).spread(function(path, scaffold){
    // Split data part from the raw scaffold
    var split = yfm.split(scaffold);
    var separator = split.separator || '---';
    var jsonMode = separator[0] === ';';
    var frontMatter = prepareFrontMatter(_.clone(data));
    var content = '';

    // Compile front-matter with data
    var renderedData = swig.compile(split.data)(frontMatter);

    // Parse front-matter
    var compiled;

    if (jsonMode){
      compiled = JSON.parse('{' + renderedData + '}');
    } else {
      compiled = yaml.load(renderedData);
    }

    // Add data which are not in the front-matter
    var keys = Object.keys(data);
    var key = '';
    var obj = compiled;

    for (var i = 0, len = keys.length; i < len; i++){
      key = keys[i];

      if (!preservedKeys[key] && obj[key] == null){
        obj[key] = data[key];
      }
    }

    // Prepend the separator
    if (split.prefixSeparator) content += separator + '\n';

    content += yfm.stringify(obj, {
      mode: jsonMode ? 'json' : ''
    });

    // Concat content
    content += split.content;

    if (data.content){
      content += '\n' + data.content;
    }

    var result = {
      path: path,
      content: content
    };

    return Promise.all([
      // Write content to file
      fs.writeFile(path, content),//写入内容
      // Create asset folder
      createAssetFolder(path, config.post_asset_folder)
    ]).then(function(){

      //http://biyeah.iteye.com/blog/1308954
      ctx.emit('new', result);
    }).thenReturn(result);
  }).nodeify(callback);
}

ctx.execFilter('new_post_path', data, {
     args: [replace],
     context: ctx
   })

执行new_post_path类型的过滤器,hexo/index.js代码如下：

1
2
3

Hexo.prototype.execFilter = function(type, data, options){
 		return this.extend.filter.exec(type, data, options);
};

路径hexo/extend/filter.js：

Filter.prototype.exec = function(type, data, options){
	  options = options || {};

	  var filters = this.list(type);
	  var ctx = options.context;//hexo实例对象
	  var args = options.args || []; //上面的[replace]

	  args.unshift(data);

	  return Promise.each(filters, function(filter){
	    return Promise.method(filter).apply(ctx, args).then(function(result){
	      args[0] = result == null ? data : result;
	      return args[0];
	    });
	  }).then(function(){
	    return args[0];
	  });
};

这里我们执行的是new_post_path的filter:
文件路径为hexo/lib/plugins/filter/new_post_path.js

function newPostPathFilter(data, replace){
  /* jshint validthis: true */
  data = data || {};

  var sourceDir = this.source_dir;
  var draftDir = pathFn.join(sourceDir, '_drafts');
  var postDir = pathFn.join(sourceDir, '_posts');
  var config = this.config;
  var newPostName = config.new_post_name;
  var permalinkDefaults = config.permalink_defaults;
  var path = data.path;
  var layout = data.layout;
  var slug = data.slug;
  var target = '';

  if (!permalink || permalink.rule !== newPostName){
    permalink = new Permalink(newPostName);
  }
  //path为undefined
  if (path){
    switch (layout){
      case 'page':
        target = pathFn.join(sourceDir, path);
        break;

      case 'draft':
        target = pathFn.join(draftDir, path);
        break;

      default:
        target = pathFn.join(postDir, path);
    }
  } else if (slug){
    switch (layout){
      case 'page':
        target = pathFn.join(sourceDir, slug, 'index');
        break;

      case 'draft':
        target = pathFn.join(draftDir, slug);
        break;

      default:
        var date = moment(data.date || Date.now());
        var keys = Object.keys(data);
        var key = '';

        var filenameData = {
          year: date.format('YYYY'),
          month: date.format('MM'),
          i_month: date.format('M'),
          day: date.format('DD'),
          i_day: date.format('D'),
          title: slug
        };

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

        target = pathFn.join(postDir, permalink.stringify(
          _.defaults(filenameData, permalinkDefaults)));
    }
  } else {
    return Promise.reject(new TypeError('Either data.path or data.slug is required!'));
  }

  if (!pathFn.extname(target)){
    target += pathFn.extname(newPostName) || '.md';
  }

  if (replace){
    return Promise.resolve(target);
  } else {
    return fs.ensurePath(target);
  }
}

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