1. plugin #

插件向第三方开发者提供了 webpack 引擎中完整的能力。使用阶段式的构建回调，开发者可以引入它们自己的行为到 webpack 构建流程中。创建插件比创建 loader 更加高级，因为你将需要理解一些 webpack 底层的内部特性来做相应的钩子

1.1 为什么需要一个插件 #

1.2 可以加载插件的常用对象 #

对象 钩子
Compiler run,compile,compilation,make,emit,done
Compilation buildModule,normalModuleLoader,succeedModule,finishModules,seal,optimize,after-seal
Module Factory beforeResolver,afterResolver,module,parser
Module
Parser program,statement,call,expression
Template hash,bootstrap,localVars,render

2. 创建插件 # 

class DonePlugin {
    constructor(options) {
        this.options = options;
    }
    apply(compiler) {

    }
}
module.exports = DonePlugin;

3. Compiler 和 Compilation #

在插件开发中最重要的两个资源就是compiler和compilation对象。理解它们的角色是扩展 webpack 引擎重要的第一步。

4. 基本插件架构 #

4.1 使用插件代码 # 

if (options.plugins && Array.isArray(options.plugins)) {
  for (const plugin of options.plugins) {
    plugin.apply(compiler);
  }
}

4.2 Compiler 插件 #

4.2.1 同步 # 

class DonePlugin {
  constructor(options) {
    this.options = options;
  }
  apply(compiler) {
    compiler.hooks.done.tap("DonePlugin", (stats) => {
      console.log("Hello ", this.options.name);
    });
  }
}
module.exports = DonePlugin;

4.2.2 异步 # 

class DonePlugin {
  constructor(options) {
    this.options = options;
  }
  apply(compiler) {
    compiler.hooks.done.tapAsync("DonePlugin", (stats, callback) => {
      console.log("Hello ", this.options.name);
      callback();
    });
  }
}
module.exports = DonePlugin;

4.3 使用插件 # 

const DonePlugin = require("./plugins/DonePlugin");
module.exports = {
  entry: "./src/index.js",
  output: {
    path: path.resolve("build"),
    filename: "bundle.js",
  },
  plugins: [new DonePlugin({ name: "zhufeng" })],
};

5. compilation 插件 #

5.1 webpack-assets-plugin.js #

plugins\webpack-assets-plugin.js


//编写个Compilation插件，用来打印本次产出的代码块和文件
class WebpackAssetsPlugin {
  constructor(options) {
    this.options = options;
  }
  apply(compiler) {
    //每当webpack开启一次新的编译 ，就会创建一个新的compilation
    compiler.hooks.compilation.tap('WebpackAssetsPlugin', (compilation) => {
      //每次根据chunk创建一个新的文件后会触发一次chunkAsset
      compilation.hooks.chunkAsset.tap('WebpackAssetsPlugin', (chunk, filename) => {
        console.log(chunk.name || chunk.id, filename);
      });
    });
  }
}
module.exports = WebpackAssetsPlugin;

6. 打包 zip #

6.1 webpack-archive-plugin.js #

plugins\webpack-archive-plugin.js

const jszip = require('jszip');
const { RawSource } = require('webpack-sources');
const { Compilation } = require('webpack');
/**
 * 1.如何获取打出后的文件名和文件内容
 * 2.如何打压缩包 
 * 3.如何向目标目录输出压缩包
 */
class WebpackArchivePlugin {
  constructor(options) {
    this.options = options;
  }
  apply(compiler) {
    compiler.hooks.compilation.tap('WebpackAssetsPlugin', (compilation) => {
      //当确定好文件，当你处理每个资源的时候处执行
      compilation.hooks.processAssets.tapPromise({ name: 'WebpackArchivePlugin' }, (assets) => {
        const zip = new jszip();
        for (const filename in assets) {
          const sourceObj = assets[filename];
          const sourceCode = sourceObj.source();
          zip.file(filename, sourceCode);
        }
        return zip.generateAsync({ type: 'nodebuffer' }).then(zipContent => {
          assets[`archive_${Date.now()}。zip`] = new RawSource(zipContent);
        });
      });
    });
  }
}
module.exports = WebpackArchivePlugin;

6.2 webpack.config.js #

webpack.config.js

const WebpackArchivePlugin = require('./plugins/webpack-archive-plugin');
  plugins: [
+   new WebpackArchivePlugin({
+     filename:'[timestamp].zip'
+   })
]

7.自动外链 #

7.自动外链 #

7.1 使用外部类库 #

能否检测代码中的 import 自动处理这个步骤?

{
  externals:{
    //key jquery是要require或import 的模块名,值 jQuery是一个全局变量名
  'jquery':'$'
}, 
  module:{}
}

7.2 思路 #

7.3 使用 plugins # 

plugins: [
  new HtmlWebpackPlugin({
            template:'./src/index.html'
  }),
  new AutoExternalPlugin({
      jquery:{//自动把jquery模块变成一个外部依赖模块
          variable:'jQuery',//不再打包，而是从window.jQuery变量上获取jquery对象
          url:'https://cdn.bootcss.com/jquery/3.1.0/jquery.js'//CDN脚本
      },
      lodash:{//自动把jquery模块变成一个外部依赖模块
          variable:'_',//不再打包，而是从window.jQuery变量上获取jquery对象
          url:'https://cdn.bootcdn.net/ajax/libs/lodash.js/4.17.21/lodash.js'//CDN脚本
      }
  })
];

7.4 AutoExternalPlugin #

AsyncSeriesBailHook factorize

let { AsyncSeriesBailHook } = require("tapable");
let factorize = new AsyncSeriesBailHook(['resolveData']);
//最后总得返回一个模块吧 switch case default 
factorize.tapAsync('factory1', (resolveData, callback) => {
  if (resolveData === 'jquery') {
    callback(null, {
      id: resolveData,
      type: '外部模块',
      source: 'window.jQuery'
    });
  } else {
    callback(null);
  }
});
//生成正常模块的工厂函数最后一个工厂函数了，
factorize.tapAsync('factory2', (resolveData, callback) => {
  callback(null, { id: resolveData, type: '正常模块', source: 'webpack打包后的内容' });
});

factorize.callAsync('jquery', (err, module) => {
  console.log(module);
});
factorize.callAsync('lodash', (err, module) => {
  console.log(module);
});

plugins\auto-external-plugin.js

const { ExternalModule } = require("webpack");
const HtmlWebpackPlugin = require('html-webpack-plugin');
/**
 * 1.需要向输出html文件中添加CDN脚本引用
 * 2.在打包生产模块的时候，截断正常的打包逻辑，变成外部依赖模块
 */
class AutoExternalPlugin{
    constructor(options){
        this.options = options;
        this.externalModules = Object.keys(this.options);//['jquery'] 进行自动外键的模块
        this.importedModules = new Set();//存放着所有的实际真正使用到的外部依赖模块
    }
    apply(compiler){
        //每种模块会对应一个模块工厂 普通模块对应的就是普通模块工厂
        //https://webpack.docschina.org/api/normalmodulefactory-hooks/
        compiler.hooks.normalModuleFactory.tap('AutoExternalPlugin',(normalModuleFactory)=>{
            //https://webpack.docschina.org/api/parser/#root
            normalModuleFactory.hooks.parser
            .for('javascript/auto')//普通 的JS文件对应的钩子就是'javascript/auto'
            .tap('AutoExternalPlugin',parser=>{
                //在parser遍历语法的过程中，如果遍历到了import节点
                //https://webpack.docschina.org/api/parser/#import
                parser.hooks.import.tap('AutoExternalPlugin',(statement,source)=>{
                    if(this.externalModules.includes(source)){
                        this.importedModules.add(source);
                    }
                });
                //https://webpack.docschina.org/api/parser/#call
                //call=HookMap key方法名 值是这个方法对应的钩子
                parser.hooks.call.for('require').tap('AutoExternalPlugin',(expression)=>{
                    let value = expression.arguments[0].value;
                    if(this.externalModules.includes(value)){
                        this.importedModules.add(value);
                    }
                });
            })
            //2.改造模块的生产过程，如果是外链模块，就直接生产一个外链模块返回
            //https://webpack.docschina.org/api/normalmodulefactory-hooks/
            normalModuleFactory.hooks.factorize.tapAsync('AutoExternalPlugin',(resolveData,callback)=>{
                let {request} = resolveData;//模块名 jquery lodash
                if(this.externalModules.includes(request)){
                    let {variable} = this.options[request];
                    //request=jquery window.jQuery
                    callback(null,new ExternalModule(variable,'window',request));
                }else{
                    callback(null);//如果是正常模块，直接向后执行。走正常的打包模块的流程
                }
            });
        });
        //是往输出的HTML中添加一个新的CDN Script标签
        compiler.hooks.compilation.tap('AutoExternalPlugin',(compilation)=>{
            HtmlWebpackPlugin.getHooks(compilation).alterAssetTags.tapAsync('AutoExternalPlugin',(htmlData,callback)=>{
                //console.log(JSON.stringify(htmlData,null,2));
                Reflect.ownKeys(this.options).filter(key=>this.importedModules.has(key)).forEach(key=>{
                    //jquery
                    htmlData.assetTags.scripts.unshift({
                        tagName:'script',
                        voidTag:false,
                        attributes:{
                            defer:false,
                            src:this.options[key].url
                        }
                    });
                })
                callback(null,htmlData);
            });
        });

    }
}
module.exports = AutoExternalPlugin;
/**
 * Node {
  type: 'ImportDeclaration',
  start: 0,
  end: 23,
  loc: SourceLocation {
    start: Position { line: 1, column: 0 },
    end: Position { line: 1, column: 23 }
  },
  range: [ 0, 23 ],
  specifiers: [
    Node {
      type: 'ImportDefaultSpecifier',
      start: 7,
      end: 8,
      loc: [SourceLocation],
      range: [Array],
      local: [Node]
    }
  ],
  source: Node {
    type: 'Literal',
    start: 14,
    end: 22,
    loc: SourceLocation { start: [Position], end: [Position] },
    range: [ 14, 22 ],
    value: 'jquery',
    raw: "'jquery'"
  }
}
jquery
 */

8.AsyncQueue #

8.1 AsyncQueue # 

let AsyncQueue = require('webpack/lib/util/AsyncQueue');
let AsyncQueue = require('./AsyncQueue');
function processor(item, callback) {
    setTimeout(() => {
        console.log('process',item);
        callback(null, item);
    }, 3000);
}
const getKey = (item) => {
    return item.key;
}
let queue  = new AsyncQueue({
    name:'createModule',parallelism:3,processor,getKey
});
const start = Date.now();
let item1 = {key:'module1'};
queue.add(item1,(err,result)=>{
    console.log(err,result);
    console.log(Date.now() - start);
});
queue.add(item1,(err,result)=>{
    console.log(err,result);
    console.log(Date.now() - start);
});
queue.add({key:'module2'},(err,result)=>{
    console.log(err,result);
    console.log(Date.now() - start);
});
queue.add({key:'module3'},(err,result)=>{
    console.log(err,result);
    console.log(Date.now() - start);
});
queue.add({key:'module4'},(err,result)=>{
    console.log(err,result);
    console.log(Date.now() - start);
});

8.2 use.js #

use.js

const QUEUED_STATE = 0;//已经 入队，待执行
const PROCESSING_STATE = 1;//处理中
const DONE_STATE = 2;//处理完成
class ArrayQueue {
    constructor() {
        this._list = [];
    }
    enqueue(item) {
        this._list.push(item);//[1,2,3]
    }
    dequeue() {
        return this._list.shift();//移除并返回数组中的第一个元素
    }
}
class AsyncQueueEntry {
    constructor(item, callback) {
        this.item = item;//任务的描述
        this.state = QUEUED_STATE;//这个条目当前的状态
        this.callback = callback;//任务完成的回调
    }
}
class AsyncQueue {
    constructor({ name, parallelism, processor, getKey }) {
        this._name = name;//队列的名字
        this._parallelism = parallelism;//并发执行的任务数
        this._processor = processor;//针对队列中的每个条目执行什么操作
        this._getKey = getKey;//函数，返回一个key用来唯一标识每个元素
        this._entries = new Map();
        this._queued = new ArrayQueue();//将要执行的任务数组队列 
        this._activeTasks = 0;//当前正在执行的数，默认值1
        this._willEnsureProcessing = false;//是否将要开始处理
    }
    add = (item, callback) => {
        const key = this._getKey(item);//获取这个条目对应的key
        const entry = this._entries.get(key);//获取 这个key对应的老的条目
        if (entry !== undefined) {
            if (entry.state === DONE_STATE) {
                process.nextTick(() => callback(entry.error, entry.result));
            } else if (entry.callbacks === undefined) {
                entry.callbacks = [callback];
            } else {
                entry.callbacks.push(callback);
            }
            return;
        }
        const newEntry = new AsyncQueueEntry(item, callback);//创建一个新的条目
        this._entries.set(key, newEntry);//放到_entries
        this._queued.enqueue(newEntry);//把这个新条目放放队列
        if (this._willEnsureProcessing === false) {
            this._willEnsureProcessing = true;
            setImmediate(this._ensureProcessing);
        }
    }
    _ensureProcessing = () => {
        //如果当前的激活的或者 说正在执行任务数行小于并发数
        while (this._activeTasks < this._parallelism) {
            const entry = this._queued.dequeue();//出队 先入先出
            if (entry === undefined) break;
            this._activeTasks++;//先让正在执行的任务数++
            entry.state = PROCESSING_STATE;//条目的状态设置为执行中
            this._startProcessing(entry);
        }
        this._willEnsureProcessing = false;
    }
    _startProcessing = (entry) => {
        this._processor(entry.item, (e, r) => {
            this._handleResult(entry, e, r);
        });
    }
    _handleResult = (entry, error, result) => {
        const callback = entry.callback;
        const callbacks = entry.callbacks;
        entry.state = DONE_STATE;//把条目的状态设置为已经完成
        entry.callback = undefined;//把callback
        entry.callbacks = undefined;
        entry.result = result;//把结果赋给entry
        entry.error = error;//把错误对象赋给entry
        callback(error, result);
        if (callbacks !== undefined) {
            for (const callback of callbacks) {
                callback(error, result);
            }
        }
        this._activeTasks--;
        if (this._willEnsureProcessing === false) {
            this._willEnsureProcessing = true;
            setImmediate(this._ensureProcessing);
        }
    }
}
module.exports = AsyncQueue;

9. 参考 #

9.1 钩子集合 #

9.1.1 收集 # 

        Object.keys(this.hooks).forEach(hookName => {
            const hook = this.hooks[hookName];
            if (hook instanceof HookMap) {
                for (let key of hook._map.keys()) {
                    hook.for(key).tap('flow', () => {
                        console.log(`|JavascriptParser|${hookName}|${hook.for(key).constructor.name}|${hook._args}|`);
                    });
                }
            } else {
                hook.tap('flow', () => {
                    console.log(`|JavascriptParser|${hookName}|${hook.constructor.name}|${hook._args}|`);
                });
            }
        });

9.1.2 触发时机 #

对象 钩子名称 类型 参数 含义
Compiler environment SyncHook 在编译器准备环境时调用，时机就在配置文件中初始化插件之后
Compiler afterEnvironment SyncHook
Compiler entryOption SyncBailHook context,entry
Compiler afterPlugins SyncHook compiler
Compiler afterResolvers SyncHook compiler
Compiler initialize SyncHook
Compiler beforeRun AsyncSeriesHook compiler
Compiler run AsyncSeriesHook compiler
Compiler infrastructureLog SyncBailHook origin,type,args
Compiler readRecords AsyncSeriesHook
Compiler normalModuleFactory SyncHook normalModuleFactory
Compiler contextModuleFactory SyncHook contextModuleFactory
Compiler beforeCompile AsyncSeriesHook params
Compiler compile SyncHook params
Compiler thisCompilation SyncHook compilation,params
Compiler compilation SyncHook compilation,params
Compiler make AsyncParallelHook compilation
Compilation addEntry SyncHook entry,options
NormalModuleFactory beforeResolve AsyncSeriesBailHook resolveData
NormalModuleFactory factorize AsyncSeriesBailHook resolveData
NormalModuleFactory resolve AsyncSeriesBailHook resolveData
NormalModuleFactory afterResolve AsyncSeriesBailHook resolveData
NormalModuleFactory createModule AsyncSeriesBailHook createData,resolveData
NormalModuleFactory module SyncWaterfallHook module,createData,resolveData
Compilation buildModule SyncHook module
Compilation normalModuleLoader SyncHook loaderContext,module
JavascriptParser program SyncBailHook ast,comments
JavascriptParser preStatement SyncBailHook statement
JavascriptParser preStatement SyncBailHook statement
JavascriptParser blockPreStatement SyncBailHook declaration
JavascriptParser preDeclarator SyncBailHook declarator,statement
JavascriptParser blockPreStatement SyncBailHook declaration
JavascriptParser statement SyncBailHook statement
JavascriptParser declarator SyncBailHook declarator,statement
JavascriptParser statement SyncBailHook statement
JavascriptParser finish SyncBailHook ast,comments
Compilation succeedModule SyncHook module
NormalModuleFactory beforeResolve AsyncSeriesBailHook resolveData
NormalModuleFactory factorize AsyncSeriesBailHook resolveData
NormalModuleFactory resolve AsyncSeriesBailHook resolveData
NormalModuleFactory afterResolve AsyncSeriesBailHook resolveData
NormalModuleFactory createModule AsyncSeriesBailHook createData,resolveData
NormalModuleFactory module SyncWaterfallHook module,createData,resolveData
Compilation buildModule SyncHook module
Compilation normalModuleLoader SyncHook loaderContext,module
JavascriptParser program SyncBailHook ast,comments
JavascriptParser preStatement SyncBailHook statement
JavascriptParser blockPreStatement SyncBailHook declaration
JavascriptParser statement SyncBailHook statement
JavascriptParser finish SyncBailHook ast,comments
Compilation succeedModule SyncHook module
Compilation succeedEntry SyncHook entry,options,module
Compilation log SyncBailHook origin,logEntry
Compiler finishMake AsyncSeriesHook compilation
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation finishModules AsyncSeriesHook modules
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation seal SyncHook
Compilation optimizeDependencies SyncBailHook modules
Compilation log SyncBailHook origin,logEntry
Compilation afterOptimizeDependencies SyncHook modules
Compilation log SyncBailHook origin,logEntry
Compilation beforeChunks SyncHook
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation afterChunks SyncHook chunks
Compilation log SyncBailHook origin,logEntry
Compilation optimize SyncHook
Compilation optimizeModules SyncBailHook modules
Compilation afterOptimizeModules SyncHook modules
Compilation optimizeChunks SyncBailHook chunks,chunkGroups
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation afterOptimizeChunks SyncHook chunks,chunkGroups
Compilation optimizeTree AsyncSeriesHook chunks,modules
Compilation afterOptimizeTree SyncHook chunks,modules
Compilation optimizeChunkModules AsyncSeriesBailHook chunks,modules
Compilation afterOptimizeChunkModules SyncHook chunks,modules
Compilation shouldRecord SyncBailHook
Compilation reviveModules SyncHook modules,records
Compilation beforeModuleIds SyncHook modules
Compilation moduleIds SyncHook modules
Compilation optimizeModuleIds SyncHook modules
Compilation afterOptimizeModuleIds SyncHook modules
Compilation reviveChunks SyncHook chunks,records
Compilation beforeChunkIds SyncHook chunks
Compilation chunkIds SyncHook chunks
Compilation optimizeChunkIds SyncHook chunks
Compilation afterOptimizeChunkIds SyncHook chunks
Compilation log SyncBailHook origin,logEntry
Compilation recordModules SyncHook modules,records
Compilation recordChunks SyncHook chunks,records
Compilation optimizeCodeGeneration SyncHook modules
Compilation log SyncBailHook origin,logEntry
Compilation beforeModuleHash SyncHook
Compilation log SyncBailHook origin,logEntry
Compilation afterModuleHash SyncHook
Compilation log SyncBailHook origin,logEntry
Compilation beforeCodeGeneration SyncHook
Compilation log SyncBailHook origin,logEntry
Compilation afterCodeGeneration SyncHook
Compilation log SyncBailHook origin,logEntry
Compilation beforeRuntimeRequirements SyncHook
Compilation additionalModuleRuntimeRequirements SyncHook module,runtimeRequirements,context
Compilation additionalModuleRuntimeRequirements SyncHook module,runtimeRequirements,context
Compilation log SyncBailHook origin,logEntry
Compilation additionalChunkRuntimeRequirements SyncHook chunk,runtimeRequirements,context
Compilation log SyncBailHook origin,logEntry
Compilation additionalTreeRuntimeRequirements SyncHook chunk,runtimeRequirements,context
Compilation log SyncBailHook origin,logEntry
Compilation afterRuntimeRequirements SyncHook
Compilation log SyncBailHook origin,logEntry
Compilation beforeHash SyncHook
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation chunkHash SyncHook chunk,chunkHash,ChunkHashContext
Compilation contentHash SyncHook chunk
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation fullHash SyncHook hash
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation afterHash SyncHook
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation recordHash SyncHook records
Compilation log SyncBailHook origin,logEntry
Compilation beforeModuleAssets SyncHook
Compilation log SyncBailHook origin,logEntry
Compilation shouldGenerateChunkAssets SyncBailHook
Compilation beforeChunkAssets SyncHook
Compilation renderManifest SyncWaterfallHook result,options
Compilation assetPath SyncWaterfallHook path,options,assetInfo
Compilation chunkAsset SyncHook chunk,filename
Compilation log SyncBailHook origin,logEntry
Compilation additionalChunkAssets Object undefined
Compilation additionalAssets Object undefined
Compilation optimizeAssets AsyncSeriesHook assets
Compilation processAssets AsyncSeriesHook assets
Compilation optimizeChunkAssets Object undefined
Compilation afterOptimizeChunkAssets Object undefined
Compilation afterOptimizeAssets SyncHook assets
Compilation afterProcessAssets SyncHook assets
Compilation log SyncBailHook origin,logEntry
Compilation record SyncHook compilation,records
Compilation needAdditionalSeal SyncBailHook
Compilation afterSeal AsyncSeriesHook
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compiler afterCompile AsyncSeriesHook compilation
Compilation log SyncBailHook origin,logEntry
Compiler shouldEmit SyncBailHook compilation
Compiler emit AsyncSeriesHook compilation
Compilation assetPath SyncWaterfallHook path,options,assetInfo
Compiler assetEmitted AsyncSeriesHook file,info
Compiler afterEmit AsyncSeriesHook compilation
Compilation log SyncBailHook origin,logEntry
Compilation needAdditionalPass SyncBailHook
Compiler emitRecords AsyncSeriesHook
Compilation log SyncBailHook origin,logEntry
Compiler done AsyncSeriesHook stats
Compilation log SyncBailHook origin,logEntry
Compilation log SyncBailHook origin,logEntry
Compiler shutdown AsyncSeriesHook
Compilation statsNormalize SyncHook options,context
Compilation statsFactory SyncHook statsFactory,options
Compilation statsPrinter SyncHook statsPrinter,options
Compilation processErrors SyncWaterfallHook errors
Compilation processWarnings SyncWaterfallHook warnings
Compiler afterDone SyncHook stats
Compiler infrastructureLog SyncBailHook origin,type,args

9.1.3 工作流 #

9.1.3.1 初始化阶段 #
事件名 解释 代码位置
读取命令行参数 从命令行中读取用户输入的参数 require("./convert-argv")(argv)
实例化 Compiler 1.用上一步得到的参数初始化 Compiler 实例
2.Compiler 负责文件监听和启动编译
3.Compiler 实例中包含了完整的 Webpack 配置，全局只有一个 Compiler 实例。
 compiler = webpack(options);
加载插件 1.依次调用插件的 apply 方法，让插件可以监听后续的所有事件节点。
同时给插件传入 compiler 实例的引用，以方便插件通过 compiler 调用 Webpack 提供的 API。		 plugin.apply(compiler)
处理入口 读取配置的 Entrys，为每个 Entry 实例化一个对应的 EntryPlugin，为后面该 Entry 的递归解析工作做准备 new EntryOptionPlugin().apply(compiler)
new SingleEntryPlugin(context, item, name)
compiler.hooks.make.tapAsync
9.1.3.2 编译阶段 #
事件名 解释 代码位置
run 启动一次新的编译 this.hooks.run.callAsync
compile 该事件是为了告诉插件一次新的编译将要启动，同时会给插件传入compiler 对象。 compile(callback)
compilation 当 Webpack 以开发模式运行时，每当检测到文件变化，一次新的 Compilation 将被创建。
一个 Compilation 对象包含了当前的模块资源、编译生成资源、变化的文件等。
Compilation 对象也提供了很多事件回调供插件做扩展。		 newCompilation(params)
make 一个新的 Compilation 创建完毕主开始编译 this.hooks.make.callAsync
addEntry 即将从 Entry 开始读取文件 compilation.addEntry
this._addModuleChain
moduleFactory 创建模块工厂 const moduleFactory = this.dependencyFactories.get(Dep)
create 创建模块 moduleFactory.create
factory 开始创建模块 factory(result, (err, module)
resolver(result
this.hooks.resolver.tap("NormalModuleFactory"
resolveRequestArray 解析loader路径 resolveRequestArray
resolve 解析资源文件路径 resolve
userRequest 得到包括loader在内的资源文件的绝对路径用!拼起来的字符串 userRequest
ruleSet.exec 它可以根据模块路径名，匹配出模块所需的loader this.ruleSet.exec
_run 它可以根据模块路径名，匹配出模块所需的loader _run
loaders 得到所有的loader数组 results[0].concat(loaders, results[1], results[2])
getParser 获取AST解析器 this.getParser(type, settings.parser)
buildModule 开始编译模块 this.buildModule(module
buildModule(module, optional, origin, dependencies, thisCallback)
build 开始真正编译入口模块 build(options
doBuild 开始真正编译入口模块 doBuild
执行loader 使用loader进行转换 runLoaders
runLoaders
iteratePitchingLoaders 开始递归执行pitch loader iteratePitchingLoaders
loadLoader 加载loader loadLoader
runSyncOrAsync 执行pitchLoader runSyncOrAsync
processResource 开始处理资源 processResource
options.readResource
iterateNormalLoaders
iterateNormalLoaders
createSource 创建源代码对象 this.createSource
parse 使用parser转换抽象语法树 this.parser.parse
parse 解析抽象语法树 parse(source, initialState)
acorn.parse 解析语法树 acorn.parse(code, parserOptions)
ImportDependency 遍历并添加添加依赖 parser.state.module.addDependency(clearDep)
succeedModule 生成语法树后就表示一个模块编译完成 this.hooks.succeedModule.call(module)
processModuleDependencies 递归编译依赖的模块 this.processModuleDependencies(module
processModuleDependencies(module, callback)
this.addModuleDependencies
buildModule
make后 结束make this.hooks.make.callAsync(compilation, err => {}
finish 编译完成 compilation.finish();
9.1.3.3 结束阶段 #
事件名 解释 代码位置
seal 封装 compilation.seal
seal(callback)
addChunk 生成资源 addChunk(name)
createChunkAssets 创建资源 this.createChunkAssets()
getRenderManifest 获得要渲染的描述文件 getRenderManifest(options)
render 渲染源码 source = fileManifest.render();
afterCompile 编译结束 this.hooks.afterCompile
shouldEmit 所有需要输出的文件已经生成好，询问插件哪些文件需要输出，哪些不需要。 this.hooks.shouldEmit
emit 确定好要输出哪些文件后，执行文件输出，可以在这里获取和修改输出内容。 this.emitAssets(compilation
this.hooks.emit.callAsync
const emitFiles = err
this.outputFileSystem.writeFile
this.emitRecords 写入记录 this.emitRecords
done 全部完成 this.hooks.done.callAsync
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