單頁面多頁面的理解，以及如何搭建多頁面應用

這樣對比的話，單頁面的優勢確實很大，但當我自己去打開某寶，某東的移動端頁面時，確實它們都是多頁面應用。為什么？我能想到的就幾點：
1.單頁面使用的技術對低版本的瀏覽器不友好，大公司還得兼顧使用低版本瀏覽器的用戶啊

2.功能模塊開發來說，比如說單頁面的業務公用組件，有時候你都不知道分給誰開發

3.seo優化吧（PS：既然是大應用應該很多人都知道，為什么還要做搜索引擎優化）

公司開發移動端使用的技術是vue，其實老大在要求使用多頁面開發的時候，已經搭了一個vue多頁面的腳手架供給我們去使用，但是我去看了看源碼的時候寫得很一般，所以決定自己重新去寫過。

思路：

由於vue-cli已經寫好了單頁面的webpack文件，不去改動之前是它默認的一個頁面引用打包的資源。既然是多頁面，那么把webpack入口文件改成多個就好了啊。未改動時的webpack.base.conf.js（這個JS的功能主要在於全局配置，比如入口文件，出口文件，解析規則等）

// 把箭頭部分的入口文件改為以下
 entry: {
   'index': '..../main.js'  // 注意省略號是實際開發時的項目路徑
   'product': '..../main.js'    
 }

但是這樣做效率得多低下，每增加一個新頁面就要手動去添加新的入口，所以這里把入口文件封裝為一個函數：

/**
 * 獲取多頁面入口文件
 * @globPath 文件路徑
 */
const glob = require('glob')
function getEntries(globPath)  {
  const entries = glob.sync(globPath).reduce((result, entry) => {
    const moduleName = path.basename(path.dirname(entry)) // 獲取模塊名稱
    result[moduleName] = entry
    return result
  }, {})
  return entries
}

注意在使用nodejs的glob模塊之前，記得先下載依賴

測試一下這個函數

然后把webpack.base.config.js改為如下:

'use strict'
const path = require('path')
const utils = require('./utils')
const config = require('../config')
const vueLoaderConfig = require('./vue-loader.conf')

function resolve (dir) {
  return path.join(__dirname, '..', dir)
}

const glob = require('glob')
function getEntries (globPath){
  const entries = glob.sync(globPath).reduce((result, entry) => {
    const moduleName = path.basename(path.dirname(entry)) // 獲取模塊名稱
    result[moduleName] = entry
    return result
  }, {})
  return entries
}

const entries = getEntries('./src/modules/**/*.js')

module.exports = {
  context: path.resolve(__dirname, '../'),
  entry: entries,   // 改動部分
  output: {
    path: config.build.assetsRoot,
    filename: '[name].js',
    publicPath: process.env.NODE_ENV === 'production'
      ? config.build.assetsPublicPath
      : config.dev.assetsPublicPath
  },
  resolve: {
    extensions: ['.js', '.vue', '.json'],
    alias: {
      'vue$': 'vue/dist/vue.esm.js',
      '@': resolve('src'),
    }
  },
  module: {
    rules: [
      {
        test: /\.vue$/,
        loader: 'vue-loader',
        options: vueLoaderConfig
      },
      {
        test: /\.js$/,
        loader: 'babel-loader',
        include: [resolve('src'), resolve('test'), resolve('node_modules/webpack-dev-server/client')]
      },
      {
        test: /\.(png|jpe?g|gif|svg)(\?.*)?$/,
        loader: 'url-loader',
        options: {
          limit: 10000,
          name: utils.assetsPath('img/[name].[hash:7].[ext]')
        }
      },
      {
        test: /\.(mp4|webm|ogg|mp3|wav|flac|aac)(\?.*)?$/,
        loader: 'url-loader',
        options: {
          limit: 10000,
          name: utils.assetsPath('media/[name].[hash:7].[ext]')
        }
      },
      {
        test: /\.(woff2?|eot|ttf|otf)(\?.*)?$/,
        loader: 'url-loader',
        options: {
          limit: 10000,
          name: utils.assetsPath('fonts/[name].[hash:7].[ext]')
        }
      }
    ]
  },
  node: {
    // prevent webpack from injecting useless setImmediate polyfill because Vue
    // source contains it (although only uses it if it's native).
    setImmediate: false,
    // prevent webpack from injecting mocks to Node native modules
    // that does not make sense for the client
    dgram: 'empty',
    fs: 'empty',
    net: 'empty',
    tls: 'empty',
    child_process: 'empty'
  }
}

注意我的多頁面目錄：

公共配置搞完之后是打包文件:webpack.prod.conf.js，打包文件的修改主要是輸出文件的配置，因為要對應入口文件的文件夾，還有就是一個頁面對應一個htmlwebpackplugin配置，這個配置是加在文件的plugins里面的，按照上面的消除手動加入配置的思路這里也加入htmlwebpackplugin的配置函數

/**
 * 頁面打包
 * @entries 打包文件
 * @config 參數配置
 * @module 使用的主體
 */
const HtmlWebpackPlugin = require('html-webpack-plugin')
function pack (entries, module) {
  for (const path in entries) {
    const conf = {
      filename: `modules/${path}/index.html`,
      template: entries[path],   // 模板路徑
      inject: true,
      chunks: ['manifest', 'vendor', path]   // 必須先引入公共依賴
    }
    module.plugins.push(new HtmlWebpackPlugin(conf))
  }
}

最終打包文件改為如下

'use strict'
const path = require('path')
const utils = require('./utils')
const webpack = require('webpack')
const config = require('../config')
const merge = require('webpack-merge')
const baseWebpackConfig = require('./webpack.base.conf')
const CopyWebpackPlugin = require('copy-webpack-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const ExtractTextPlugin = require('extract-text-webpack-plugin')
const OptimizeCSSPlugin = require('optimize-css-assets-webpack-plugin')
const UglifyJsPlugin = require('uglifyjs-webpack-plugin')

const env = require('../config/prod.env')


const glob = require('glob')
function getEntries (globPath){
  const entries = glob.sync(globPath).reduce((result, entry) => {
    const moduleName = path.basename(path.dirname(entry)) // 獲取模塊名稱
    result[moduleName] = entry
    return result
  }, {})
  return entries
}

const entries = getEntries('./src/modules/**/*.html')   // 獲取多頁面所有入口文件

const webpackConfig = merge(baseWebpackConfig, {
  module: {
    rules: utils.styleLoaders({
      sourceMap: config.build.productionSourceMap,
      extract: true,
      usePostCSS: true
    })
  },
  devtool: config.build.productionSourceMap ? config.build.devtool : false,
  output: {
    path: config.build.assetsRoot,
    filename: 'modules/[name]/[name].[chunkhash].js',
    // publicPath: '/' // 改為相對路徑
    // chunkFilename: utils.assetsPath('js/[id].[chunkhash].js')
  },
  plugins: [
    // http://vuejs.github.io/vue-loader/en/workflow/production.html
    new webpack.DefinePlugin({
      'process.env': env
    }),
    new UglifyJsPlugin({
      uglifyOptions: {
        compress: {
          warnings: false
        }
      },
      sourceMap: config.build.productionSourceMap,
      parallel: true
    }),
    // extract css into its own file
    new ExtractTextPlugin({
      filename: utils.assetsPath('css/[name].[contenthash].css'),
      // Setting the following option to `false` will not extract CSS from codesplit chunks.
      // Their CSS will instead be inserted dynamically with style-loader when the codesplit chunk has been loaded by webpack.
      // It's currently set to `true` because we are seeing that sourcemaps are included in the codesplit bundle as well when it's `false`, 
      // increasing file size: https://github.com/vuejs-templates/webpack/issues/1110
      allChunks: true,
    }),
    // Compress extracted CSS. We are using this plugin so that possible
    // duplicated CSS from different components can be deduped.
    new OptimizeCSSPlugin({
      cssProcessorOptions: config.build.productionSourceMap
        ? { safe: true, map: { inline: false } }
        : { safe: true }
    }),
    // generate dist index.html with correct asset hash for caching.
    // you can customize output by editing /index.html
    // see https://github.com/ampedandwired/html-webpack-plugin
    // keep module.id stable when vendor modules does not change
    new webpack.HashedModuleIdsPlugin(),
    // enable scope hoisting
    new webpack.optimize.ModuleConcatenationPlugin(),
    // split vendor js into its own file
    new webpack.optimize.CommonsChunkPlugin({
      name: 'vendor',
      minChunks (module) {
        // any required modules inside node_modules are extracted to vendor
        return (
          module.resource &&
          /\.js$/.test(module.resource) &&
          module.resource.indexOf(
            path.join(__dirname, '../node_modules')
          ) === 0
        )
      }
    }),
    // extract webpack runtime and module manifest to its own file in order to
    // prevent vendor hash from being updated whenever app bundle is updated
    new webpack.optimize.CommonsChunkPlugin({
      name: 'manifest',
      minChunks: Infinity
    }),
    // This instance extracts shared chunks from code splitted chunks and bundles them
    // in a separate chunk, similar to the vendor chunk
    // see: https://webpack.js.org/plugins/commons-chunk-plugin/#extra-async-commons-chunk
    new webpack.optimize.CommonsChunkPlugin({
      name: 'app',
      async: 'vendor-async',
      children: true,
      minChunks: 3
    }),

    // copy custom static assets
    new CopyWebpackPlugin([
      {
        from: path.resolve(__dirname, '../static'),
        to: config.build.assetsSubDirectory,
        ignore: ['.*']
      }
    ])
  ]
})

if (config.build.productionGzip) {
  const CompressionWebpackPlugin = require('compression-webpack-plugin')

  webpackConfig.plugins.push(
    new CompressionWebpackPlugin({
      asset: '[path].gz[query]',
      algorithm: 'gzip',
      test: new RegExp(
        '\\.(' +
        config.build.productionGzipExtensions.join('|') +
        ')$'
      ),
      threshold: 10240,
      minRatio: 0.8
    })
  )
}

if (config.build.bundleAnalyzerReport) {
  const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin
  webpackConfig.plugins.push(new BundleAnalyzerPlugin())
}


function pack (entries, module) {
  for (const path in entries) {
    const conf = {
      filename: `modules/${path}/index.html`,
      template: entries[path],   // 模板路徑
      inject: true,
      chunks: ['manifest', 'vendor', path]   // 必須先引入公共依賴
    }
    module.plugins.push(new HtmlWebpackPlugin(conf))
  }
}

pack(entries, webpackConfig)
module.exports = webpackConfig

然后啟動npm run build嘗試打包文件

OK，多頁面的打包完成