首先,小程序原生代码是比较难运行在浏览器端的,想要通过这个思路实现的朋友可以试试wept,但是wept已经不更新了。查阅了一些资料后,最终采用的思路是:小程序使用mpvue开发(一个类vue框架),而mpvue工程转化为vue工程并适配到浏览器。
那么,接下来的问题是:

  1. 如何将mpvue工程打包为vue工程
  2. 打包成vue工程后,需要做哪些适配

如何将mpvue工程打包为vue工程

针对第一个问题,主要思路编写mpvue打包成vue工程的webpack配置即可,期间参考了一下网上的资料总算搞定了。在开始编写配置文件前,首先确认mpvue版本,打开工程根目录package.json,节选如下:

"dependencies": {
   "axios": "^0.18.0",
   "mpvue": "^1.0.11",
   "mpvue-wxparse": "^0.6.5",
   "vue": "^2.5.16",
   "vue-router": "^3.0.1",
   "vuex": "^3.0.1"
 },

mpvue新版本的打包配置和旧版有微妙的区别,本文选择的是1.0.11版本。
接下来,大致分为如下几步:

  1. 添加buildH5配置
  2. 添加configH5配置
  3. 代码入口适配
  4. 添加编译命令

添加buildH5配置

标准mpvue工程在根目录下都会有一个build目录。现在为了生成vue工程,需要新建一个buildH5目录。该目录下需要添加如下文件,这些配置几乎和项目没什么关系,不用改动:

build.js

require('./check-versions')()

process.env.NODE_ENV = 'production'

var ora = require('ora')
var rm = require('rimraf')
var path = require('path')
var chalk = require('chalk')
var webpack = require('webpack')
var config = require('../configH5')
var webpackConfig = require('./webpack.prod.conf')

var spinner = ora('building for production...')
spinner.start()

rm(path.join(config.build.assetsRoot, config.build.assetsSubDirectory), err => {
  if (err) throw err
  webpack(webpackConfig, (err, stats) => {
    spinner.stop()
    if (err) throw err
    process.stdout.write(stats.toString({
      colors: true,
      modules: false,
      children: false, // If you are using ts-loader, setting this to true will make TypeScript errors show up during build.
      chunks: false,
      chunkModules: false
    }) + '\n\n')

    if (stats.hasErrors()) {
      console.log(chalk.red('  Build failed with errors.\n'))
      process.exit(1)
    }

    console.log(chalk.cyan('  Build complete.\n'))
    console.log(chalk.yellow(
      '  Tip: built files are meant to be served over an HTTP server.\n' +
      '  Opening index.html over file:// won\'t work.\n'
    ))
  })
})

check-versions.js

'use strict'
const chalk = require('chalk')
const semver = require('semver')
const packageConfig = require('../package.json')
const shell = require('shelljs')

function exec (cmd) {
 return require('child_process').execSync(cmd).toString().trim()
}

const versionRequirements = [
 {
   name: 'node',
   currentVersion: semver.clean(process.version),
   versionRequirement: packageConfig.engines.node
 }
]

if (shell.which('npm')) {
 versionRequirements.push({
   name: 'npm',
   currentVersion: exec('npm --version'),
   versionRequirement: packageConfig.engines.npm
 })
}

module.exports = function () {
 const warnings = []

 for (let i = 0; i < versionRequirements.length; i++) {
   const mod = versionRequirements[i]

   if (!semver.satisfies(mod.currentVersion, mod.versionRequirement)) {
     warnings.push(mod.name + ': ' +
       chalk.red(mod.currentVersion) + ' should be ' +
       chalk.green(mod.versionRequirement)
     )
   }
 }

 if (warnings.length) {
   console.log('')
   console.log(chalk.yellow('To use this template, you must update following to modules:'))
   console.log()

   for (let i = 0; i < warnings.length; i++) {
     const warning = warnings[i]
     console.log('  ' + warning)
   }

   console.log()
   process.exit(1)
 }
}

dev-client.js

/* eslint-disable */
require('eventsource-polyfill')
var hotClient = require('webpack-hot-middleware/client?noInfo=true&reload=true')

hotClient.subscribe(function (event) {
  if (event.action === 'reload') {
    window.location.reload()
  }
})

utils.js

'use strict'
const path = require('path')
const config = require('../configH5')
const ExtractTextPlugin = require('extract-text-webpack-plugin')
const packageConfig = require('../package.json')

exports.assetsPath = function (_path) {
  const assetsSubDirectory = process.env.NODE_ENV === 'production'
    ? config.build.assetsSubDirectory
    : config.dev.assetsSubDirectory
  return path.posix.join(assetsSubDirectory, _path)
}

exports.cssLoaders = function (options) {
  // console.log(options || {}, options)
  options = options || {}
  // console.log('generateLoaders', options.usePostCSS)
  const cssLoader = {
    loader: 'css-loader',
    options: {
      sourceMap: options.sourceMap
    }
  }

  const postcssLoader = {
    loader: 'postcss-loader',
    options: {
      sourceMap: options.sourceMap
    }
  }

  // generate loader string to be used with extract text plugin
  function generateLoaders (loader, loaderOptions) {
    const loaders = options.usePostCSS ? [cssLoader, postcssLoader] : [cssLoader]
    // , postcssLoader
    if (loader) {
      loaders.push({
        loader: loader + '-loader',
        options: Object.assign({}, loaderOptions, {
          sourceMap: options.sourceMap
        })
      })
    }
    // Extract CSS when that option is specified
    // (which is the case during production build)
    if (options.extract) {
      return ExtractTextPlugin.extract({
        use: loaders,
        fallback: 'vue-style-loader'
      })
    } else {
      return ['vue-style-loader'].concat(loaders)
    }
  }
  // https://vue-loader.vuejs.org/en/configurations/extract-css.html
  return {
    css: generateLoaders(),
    postcss: generateLoaders(),
    less: generateLoaders('less'),
    sass: generateLoaders('sass', { indentedSyntax: true }),
    scss: generateLoaders('sass'),
    stylus: generateLoaders('stylus'),
    styl: generateLoaders('stylus')
  }
}
// Generate loaders for standalone style files (outside of .vue)
exports.styleLoaders = function (options) {
  const output = []
  const loaders = exports.cssLoaders(options)
  for (const extension in loaders) {
    const loader = loaders[extension]
    output.push({
      test: new RegExp('\\.' + extension + '$'),
      use: loader
    })
  }
  return output
}

exports.createNotifierCallback = () => {
  const notifier = require('node-notifier')
  return (severity, errors) => {
    if (severity !== 'error') return
    const error = errors[0]
    const filename = error.file && error.file.split('!').pop()
    notifier.notify({
      title: packageConfig.name,
      message: severity + ': ' + error.name,
      subtitle: filename || '',
      icon: path.join(__dirname, 'logo.png')
    })
  }
}

vue-loader.conf.js

'use strict'
const utils = require('./utils')
const config = require('../configH5')
const isProduction = process.env.NODE_ENV === 'production'
const sourceMapEnabled = isProduction
  ? config.build.productionSourceMap
  : config.dev.cssSourceMap

module.exports = {
  loaders: utils.cssLoaders({
    sourceMap: sourceMapEnabled,
    extract: isProduction
  }),
  cssSourceMap: sourceMapEnabled,
  cacheBusting: config.dev.cacheBusting,
  transformToRequire: {
    video: ['src', 'poster'],
    source: 'src',
    img: 'src',
    image: 'xlink:href'
  }
}

webpack.base.conf.js

'use strict'
const path = require('path')
const utils = require('./utils')
const config = require('../configH5')
const vueLoaderConfig = require('./vue-loader.conf')

function resolve (dir) {
  return path.join(__dirname, '..', dir)
}
const createLintingRule = () => ({
  test: /\.(js|vue)$/,
  loader: 'eslint-loader',
  enforce: 'pre',
  include: [resolve('src'), resolve('test')],
  options: {
    formatter: require('eslint-friendly-formatter'),
    emitWarning: !config.dev.showEslintErrorsInOverlay
  }
})
module.exports = {
  context: path.resolve(__dirname, '../'),
  entry: {
    app: './src/mainH5.js'
    // app: './module/' + enterdir + '/src/main.js'
  },
  output: {
    path: config.build.assetsRoot,
    filename: '[name].js',
    publicPath: process.env.NODE_ENV === 'production'
      ? '.' + config.build.assetsPublicPath
      : config.dev.assetsPublicPath
  },
  resolve: {
    extensions: ['.js', '.vue', '.json', '.html'],
    alias: {
      'vue$': 'vue/dist/vue.esm.js',
      '@': resolve('src'),
      'pages': resolve('src/pages'),
      'packageA': resolve('src/pages/packageA'),
      'packageB': resolve('src/pages/packageB'),
    }
  },
  module: {
    rules: [
      ...(config.dev.useEslint ? [createLintingRule()] : []),
      {
        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: /\.css$/,
        use: [
          'vue-style-loader',
          'px2rpx-loader',
          'css-loader'
        ],
      },
      {
            test: /\.less$/,

            loader: "style-loader!css-loader!less-loader",
      },
      {
        test: /\.(png|jpe?g|gif|svg)(\?.*)?$/,
        loader: 'url-loader',
        options: {
          limit: 1000,
          name: utils.assetsPath('img/[name].[ext]?v=[hash:7]')
        }
      },
      {
        test: /\.(mp4|webm|ogg|mp3|wav|flac|aac)(\?.*)?$/,
        loader: 'url-loader',
        options: {
          limit: 1000,
          name: utils.assetsPath('media/[name].[ext]?v=[hash:7]')
        }
      },
      {
        test: /\.(woff2?|eot|ttf|otf)(\?.*)?$/,
        loader: 'url-loader',
        options: {
          limit: 10000,
          name: utils.assetsPath('fonts/[name].[ext]?v=[hash:7]')
        }
      }
    ]
  },
  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'
  }
}

webpack.dev.conf.js

'use strict'
const utils = require('./utils')
const webpack = require('webpack')
const config = require('../configH5')
const merge = require('webpack-merge')
const path = require('path')
const baseWebpackConfig = require('./webpack.base.conf')
const CopyWebpackPlugin = require('copy-webpack-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const FriendlyErrorsPlugin = require('friendly-errors-webpack-plugin')
const portfinder = require('portfinder')

const HOST = process.env.HOST
const PORT = process.env.PORT && Number(process.env.PORT)

const devWebpackConfig = merge(baseWebpackConfig, {
  module: {
    rules: utils.styleLoaders({ sourceMap: config.dev.cssSourceMap, usePostCSS: false})
  },
  // cheap-module-eval-source-map is faster for development
  devtool: config.dev.devtool,

  // these devServer options should be customized in /config/index.js
  devServer: {
    clientLogLevel: 'warning',
    historyApiFallback: {
      rewrites: [
        { from: /.*/, to: path.posix.join(config.dev.assetsPublicPath, 'index.html') },
      ],
    },
    hot: true,
    contentBase: false, // since we use CopyWebpackPlugin.
    compress: true,
    host: HOST || config.dev.host,
    port: PORT || config.dev.port,
    open: config.dev.autoOpenBrowser,
    overlay: config.dev.errorOverlay
      ? { warnings: false, errors: true }
      : false,
    publicPath: config.dev.assetsPublicPath,
    proxy: config.dev.proxyTable,
    quiet: true, // necessary for FriendlyErrorsPlugin
    watchOptions: {
      poll: config.dev.poll,
    }
  },
  plugins: [
    new webpack.DefinePlugin({
      'process.env': require('../configH5/dev.env')
    }),
    new webpack.HotModuleReplacementPlugin(),
    new webpack.NamedModulesPlugin(), // HMR shows correct file names in console on update.
    new webpack.NoEmitOnErrorsPlugin(),
    // https://github.com/ampedandwired/html-webpack-plugin
    new HtmlWebpackPlugin({
      filename: 'index.html',
      template: 'index.html',
      inject: true
    }),
    // copy custom static assets
    new CopyWebpackPlugin([
      {
        from: path.resolve(__dirname, '../static'),
        to: config.dev.assetsSubDirectory,
        ignore: ['.*']
      }
    ]),
    new CopyWebpackPlugin([
      {
        from: path.resolve(__dirname, '../src/app.json'),
        to: config.dev.assetsSubDirectory + '/../app.json',
        ignore: ['.*']
      }
    ]),
    new CopyWebpackPlugin([
      {
        from: path.resolve(__dirname, '../project.config.json'),
        to: config.dev.assetsSubDirectory + '/../project.config.json',
        ignore: ['.*']
      }
    ])
  ]
})

module.exports = new Promise((resolve, reject) => {
  portfinder.basePort = process.env.PORT || config.dev.port
  portfinder.getPort((err, port) => {
    if (err) {
      reject(err)
    } else {
      // publish the new Port, necessary for e2e tests
      process.env.PORT = port
      // add port to devServer config
      devWebpackConfig.devServer.port = port

      // Add FriendlyErrorsPlugin
      devWebpackConfig.plugins.push(new FriendlyErrorsPlugin({
        compilationSuccessInfo: {
          messages: [`Your application is running here: http://${devWebpackConfig.devServer.host}:${port}`],
        },
        onErrors: config.dev.notifyOnErrors
          ? utils.createNotifierCallback()
          : undefined
      }))

      resolve(devWebpackConfig)
    }
  })
})

webpack.prod.conf.js

'use strict'
const path = require('path')
const utils = require('./utils')
const webpack = require('webpack')
const config = require('../configH5/index')
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 = process.env.NODE_ENV === 'testing'
  ? require('../configH5/test.env')
  : require('../configH5/prod.env')

const webpackConfig = merge(baseWebpackConfig, {
  module: {
    rules: utils.styleLoaders({
      sourceMap: config.build.productionSourceMap,
      extract: false,
      usePostCSS: false
    })
  },
  devtool: config.build.productionSourceMap ? config.build.devtool : false,
  output: {
    path: config.build.assetsRoot,
    filename: utils.assetsPath('js/[name].js?v=[chunkhash]'),
    chunkFilename: utils.assetsPath('js/[id].js?v=[chunkhash]')
  },
  plugins: [
    // http://vuejs.github.io/vue-loader/en/workflow/production.html
    new webpack.DefinePlugin({
      'process.env': env
    }),
    new UglifyJsPlugin({
      uglifyOptions: {
        compress: {
          warnings: false
        }
      },
      sourceMap: true,
      parallel: true
    }),
    // extract css into its own file
    //
    new ExtractTextPlugin({
      filename: utils.assetsPath('css/[name].css?v=[contenthash]'),
      // 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
    new HtmlWebpackPlugin({
      filename: config.build.index,
      template: 'index.html',
      inject: true,
      minify: false,
      // minify: {
      //   removeComments: true,
      //   collapseWhitespace: true,
      //   removeAttributeQuotes: true
      //   // more options:
      //   // https://github.com/kangax/html-minifier#options-quick-reference
      // },
      // necessary to consistently work with multiple chunks via CommonsChunkPlugin
      chunksSortMode: 'dependency'
    }),
    // 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: ['.*']
      }
    ]),
    new CopyWebpackPlugin([
      {
        from: path.resolve(__dirname, '../src/app.json'),
        to: config.dev.assetsSubDirectory + '/../app.json',
        ignore: ['.*']
      }
    ]),
    new CopyWebpackPlugin([
      {
        from: path.resolve(__dirname, '../project.config.json'),
        to: config.dev.assetsSubDirectory + '/../project.config.json',
        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())
}

module.exports = webpackConfig

需要注意的是,webpack.base.conf.js中用了诸如px2rpx-loader、vue-style-loader,如果没有安装会提示报错,照着报错安装下就好了。

添加configH5配置

同样地,在工程根目录下新建configH5目录,目录下需要添加几个文件。

dev.env.js

var merge = require('webpack-merge')
var prodEnv = require('./prod.env')

module.exports = merge(prodEnv, {
  NODE_ENV: '"development"'
})

prod.env.js

module.exports = {
  NODE_ENV: '"production"'
}

index.js

'use strict'
// Template version: 1.3.1
// see http://vuejs-templates.github.io/webpack for documentation.

const path = require('path')

module.exports = {
  dev: {

    // Paths
    assetsSubDirectory: 'static',
    assetsPublicPath: '/',
    proxyTable: {},

    // Various Dev Server settings
    host: 'localhost', // can be overwritten by process.env.HOST
    port: 8080, // can be overwritten by process.env.PORT, if port is in use, a free one will be determined
    autoOpenBrowser: false,
    errorOverlay: true,
    notifyOnErrors: true,
    poll: false, // https://webpack.js.org/configuration/dev-server/#devserver-watchoptions-

    // Use Eslint Loader?
    // If true, your code will be linted during bundling and
    // linting errors and warnings will be shown in the console.
    useEslint: false,
    // If true, eslint errors and warnings will also be shown in the error overlay
    // in the browser.
    showEslintErrorsInOverlay: false,

    /**
     * Source Maps
     */

    // https://webpack.js.org/configuration/devtool/#development
    devtool: 'cheap-module-eval-source-map',

    // If you have problems debugging vue-files in devtools,
    // set this to false - it *may* help
    // https://vue-loader.vuejs.org/en/options.html#cachebusting
    cacheBusting: true,

    cssSourceMap: true
  },

  build: {
    // Template for index.html
    index: path.resolve(__dirname, '../distH5/index.html'),

    // Paths
    assetsRoot: path.resolve(__dirname, '../distH5'),
    assetsSubDirectory: 'static',
    assetsPublicPath: '/',

    /**
     * Source Maps
     */

    productionSourceMap: false,
    // https://webpack.js.org/configuration/devtool/#production
    devtool: '#source-map',

    // Gzip off by default as many popular static hosts such as
    // Surge or Netlify already gzip all static assets for you.
    // Before setting to `true`, make sure to:
    // npm install --save-dev compression-webpack-plugin
    productionGzip: false,
    productionGzipExtensions: ['js', 'css'],

    // Run the build command with an extra argument to
    // View the bundle analyzer report after build finishes:
    // `npm run build --report`
    // Set to `true` or `false` to always turn it on or off
    bundleAnalyzerReport: process.env.npm_config_report
  }
}

代码入口适配

细心看过上面那些配置文件的人应该已经发现,入口是这样配置的:

entry: {
    app: './src/mainH5.js'
    // app: './module/' + enterdir + '/src/main.js'
  },

下面实现mainH5.js

import Vue from 'vue'
import App from './AppH5'
import router from './router'
import global from './utils/global.js'
import store from './store/index.js'
import {loginUtils} from './utils/LoginUtils'
// import '../static/fonts/icomoon.css'

// 试工程实际情况,这里可能有项目独特的配置,总之把main.js复制过来就好了
Vue.use(global);
Vue.prototype.$store = store;
Vue.config.productionTip = false;
Vue.prototype.$customEvent = new Vue(App);
App.mpType = 'app';
Vue.mixin(loginUtils)
Vue.prototype.$bus = new Vue()
Vue.config.productionTip = false

/* eslint-disable no-new */
let vue = new Vue({
  el: '#app',
  router,
  components: { App },
  template: '<div><App/></div>',
  store,
})

window.router = router

似乎和main.js没有太大区别?没有关系,稍后就有新建一个入口文件的必要了。这里的一个区别是:

import App from './AppH5'

引入的不是默认的App.vue呢。那么接下来新建AppH5.vue,放在mainH5.js同级目录下:

<template>
  <div id="app">
    <router-view></router-view>
  </div>
</template>

<script>
  export default {
    name: 'App'
  }
</script>
<style>
</style>

可以看到这里用了router。mpvue开发小程序大概率不会用router,因为有wx.navigateTo这种原生api,但是浏览器可不会识别wx api,因此路由需要由router实现。
在src下新建一个router目录,目录下新建一个index.js,在这个文件中,把所有页面注册:

import Vue from 'vue'
import Router from 'vue-router'
import main from '../pages/main/index'
import my from '../pages/my/index'

Vue.use(Router)

export default new Router({
  routes: [
    {
      path: '/',
      name: 'main',
      component: main,
      alias: '/pages/main/main'
    },
    {
      path: '/pages/my/main',
      name: 'my',
      component: my
    }
  ]
})

这里只是一个示例,实际项目要把所有页面写到这个配置中。

添加编译命令

就像npm run dev、npm run build一样,我们需要一个相似的命令生成vue工程。修改package.json,就像这样:

"scripts": {
    "dev": "node build/dev-server.js",
    "start": "node build/dev-server.js",
    "build": "node build/build.js",
    "devH5": "webpack-dev-server --iframe --progress --config buildH5/webpack.dev.conf.js",
    "all": "npm run dev && npm run devH5",
    "buildH5": "node buildH5/build.js"
  },

现在可以用npm run devH5生成项目在webpack-dev-server上的预览,或用npm run buildH5生成vue工程了,只不过生成出来的东西暂时没法跑,应该全是报错吧(笑),接下来需要做一些适配工作。

小程序工程适配为vue工程

之前提到过,wx api在浏览器端不识别,这个显然需要适配。然而除了这个,小程序的生命周期、组件也是问题。

适配wx api

首先需要新建utils/wx.js,将所有用到的wx api封装起来:

  getParams: function (target) {
    return target.$route.query
  },
 redirectTo: function (url, target) {
    let route = target.$router.matcher.match(url.url)
    if (route) {
      window.parent.onRedirectTo(route)
    }
    target.$router.replace(url.url)
  },
  switchTab: function (url, target) {
    let route = target.$router.matcher.match(url.url)
    if (route) {
      window.parent.onSwitchTab(route)
    }
    target.$router.replace(url.url)
  },

  navigateBack: function (delta, target) {
    let r = window.parent.onNavigateBack(delta)
    target.$router.replace(r.path)
  },

  reLaunch: function (url, target) {
    let route = target.$router.matcher.match(url.url)
    if (route) {
      window.parent.onRelaunch(route)
    }
    target.$router.replace(url.url)
  },

  getSystemInfoSync() {
    return {
      screenWidth: 750,
      screenHeight: 1334,
      windowWidth: 750,
      windowHeight: 1334
    }
  },

这里只展示了部分wx api在浏览器端的实现,有需要的自行实现或适配。
注意getParams,在mpvue中,接收上一个页面传的query参数可以这么写:

mounted () {
  let id = this.$root.$mp.query.id
}

但这种方式并不适用于vue,所以改为用router的方式获取参数,而页面组件中,调用封装的getParams方法即可。

适配生命周期

小程序中onLoad、onShow、onUnLoad等生命周期在vue里可是行不通的。当然,新项目可以通过开发上的约定,例如必须使用vue生命周期、不使用小程序生命周期来适配,而老项目一个个改就显得麻烦了。因此,这里的思路是在vue的runtime里加入小程序的生命周期,即定制。
这里需要修改node_modules/vue/dist/vue.esm.js:

var LIFECYCLE_HOOKS = [
  'beforeCreate',
  'created',
  'onLoad', // 加入生命周期
  'onShow', // 加入生命周期
  'beforeMount',
  'mounted',
  'beforeUpdate',
  'updated',
  'beforeDestroy',
  'onUnload', // 加入生命周期
  'destroyed',
  'activated',
  'deactivated',
  'errorCaptured'
];

还是这个文件,修改initMixin方法:

vm._self = vm;
    initLifecycle(vm);
    initEvents(vm);
    initRender(vm);
    callHook(vm, 'beforeCreate');
    initInjections(vm); // resolve injections before data/props
    initState(vm);
    initProvide(vm); // resolve provide after data/props
    callHook(vm, 'created');
    callHook(vm, 'onLoad'); // 调起生命周期
    callHook(vm, 'onShow'); // 调起生命周期

    /* istanbul ignore if */
    if (process.env.NODE_ENV !== 'production' && config.performance && mark) {
      vm._name = formatComponentName(vm, false);
      mark(endTag);
      measure(("vue " + (vm._name) + " init"), startTag, endTag);
    }

    if (vm.$options.el) {
      vm.$mount(vm.$options.el);
    }
    // 下略

找到Vue.prototype.$destroy,在代码里加入一行onUnload的调起:

Vue.prototype.$destroy = function () {
    var vm = this;
    if (vm._isBeingDestroyed) {
      return
    }
    callHook(vm, 'beforeDestroy');
    callHook(vm, 'onUnload'); // 调起生命周期
    vm._isBeingDestroyed = true;
    // remove self from parent
    var parent = vm.$parent;
    if (parent && !parent._isBeingDestroyed && !vm.$options.abstract) {
      remove(parent.$children, vm);
    }
    // 下略
}

现在vue可以调起小程序的生命周期了。

适配组件

小程序原生开发了许多组件,这些组件作为html标签当然无法被浏览器识别,有些甚至和html冲突(例如小程序的input,在html里也有个同名的)。这里适配有相当的工作量,因为组件之多、组件的属性、方法之多是需要一个团队来完成的。然而,要达到预览效果的话,仅需要适配常用组件已经常用的属性就行了。

以小程序image标签为例。首先,在工程src下新建componentsH5目录,目录下新建wx-image.vue:

<template>
  <div ref="img_loader" v-if="mode !== 'aspectFix'" style="display: flex; flex-direction: row; justify-content: center; align-items: center; overflow: hidden;">
    <img :src="resolvedSrc" :calprop="resolveSize" :style="rStyle" />
  </div>
  <div ref="img_loader" v-else style="display: flex; flex-direction: column; justify-content: center; align-items: center; overflow: hidden;">
    <img :src="resolvedSrc" :calprop="resolveSize" :style="rStyle" />
  </div>
</template>

<script>
  export default {
    name: "wx-image",
    props: {
      src: {
        type: String
      },
      mode: {
        type: String
      }
    },
    data () {
      return {
        rStyle: {}
      }
    },
    computed: {
      resolvedSrc () {
        if (!this.src) {
          return this.src
        }
        if (this.src.startsWith(('/static'))) {
          return '.' + this.src
        } else {
          return this.src
        }
      },
      resolveSize () {
        if (!this.src) {
          this.rStyle = {width: '100%', height: '100%'}
          return
        }
        let self = this
        let img = new Image()
        img.src = self.src
        let mode = self.mode
        let imgWidth = img.width
        let imgHeight = img.height
        let resolvedWidth = imgWidth
        let resolvedHeight = imgHeight

        setTimeout(function () {
          let border = self.$refs.img_loader.getBoundingClientRect()
          let borderWidth = border.width
          let borderHeight = border.height || imgHeight
          if (borderHeight === 0 || imgHeight === 0) {
            self.rStyle =  {width: '100%', height: '100%'}
            return
          }
          if (!mode) {
            self.rStyle =  {width: borderWidth + 'px', height: borderHeight + 'px'}
            return
          } else if (mode === 'scaleToFill') {
            self.rStyle =  {width: '100%', height: '100%'}
            return
          } else if (mode === 'aspectFit') {
            console.log('aspectFit');
            // 保持横纵比缩放,长边显示
            if (borderWidth / borderHeight > imgWidth / imgHeight) {
              resolvedWidth = imgWidth / imgHeight * borderHeight
              resolvedHeight = borderHeight
              console.log('aspectFit1', borderWidth, borderHeight, resolvedWidth, resolvedHeight);
            } else {
              resolvedWidth = borderWidth
              resolvedHeight = borderWidth * imgHeight / imgWidth
              console.log('aspectFit2', borderWidth, borderHeight, resolvedWidth, resolvedHeight);
            }
          } else if (mode === 'aspectFill') {
            // 保持横纵比缩放,长边裁剪
            if (borderWidth / borderHeight > imgWidth / imgHeight) {
              resolvedWidth = borderWidth
              resolvedHeight = borderWidth * imgHeight / imgWidth
            } else {
              resolvedWidth = imgWidth / imgHeight * borderHeight
              resolvedHeight = borderHeight
            }
          } else if (mode === 'aspectFix') {
            // 宽度不变,高度自适应
            resolvedWidth = borderWidth
            resolvedHeight = borderWidth * imgHeight / imgWidth
          }

          self.rStyle =  {width: resolvedWidth + 'px', height: resolvedHeight + 'px'}
        })
        return {}
      }
    }
  }
</script>

<style scoped>

</style>

在这里,适配了image两个最重要的属性:src和mode。注意,计算属性resolvedSrc将"/static"开头的传入值自动转化成了"./static",这是因为生成的vue工程放在服务端并作为静态资源暴露的时候,写作"/static/*"格式的本地图片无法显示,所以适配成更兼容的格式。另一方面,mode对小程序中4大缩放模式做了简单的适配,保证显示效果。

那么,我们只要全局注册一个名为的image组件,其实现是wx-image.vue就好了!修改mainH5.js:

// 引入组件库
import wxImage from './componentsH5/wx-image'

// 全局mixin
Vue.mixin({
  components: {
    'image': wxImage
  }
})

之前新建mainH5.js而不是直接用main.js的理由在此,我们需要在这里一一注册我们的适配组件。
但是很遗憾,这样无法通过vue的编译,查看vue源码发现,vue禁止image作为组件名:

export function validateComponentName (name: string) {
  if (!/^[a-zA-Z][\w-]*$/.test(name)) {
    warn(
      'Invalid component name: "' + name + '". Component names ' +
      'can only contain alphanumeric characters and the hyphen, ' +
      'and must start with a letter.'
    )
  }
  if (isBuiltInTag(name) || config.isReservedTag(name)) {
    warn(
      'Do not use built-in or reserved HTML elements as component ' +
      'id: ' + name
    )
  }
}

这里方法1是修改vue源码,去掉这个限制,思路2是修改打包,将image标签自动转化为wx-image标签。这里选择的是方法2,找到node_modules/vue-template-compiler/build.js,搜索2403行左右的parseHTML,如下修改:

parseHTML(template, {
    warn: warn$1,
    expectHTML: options.expectHTML,
    isUnaryTag: options.isUnaryTag,
    canBeLeftOpenTag: options.canBeLeftOpenTag,
    shouldDecodeNewlines: options.shouldDecodeNewlines,
    shouldDecodeNewlinesForHref: options.shouldDecodeNewlinesForHref,
    shouldKeepComment: options.comments,
    start: function start (tag, attrs, unary) {
      // check namespace.
      // inherit parent ns if there is one
      var ns = (currentParent && currentParent.ns) || platformGetTagNamespace(tag);
      // 将微信小程序组件简单适配到h5
      // 添加的代码
      if (tag === 'view') {
        tag = 'div'
      }
      if (tag === 'image') {
        tag = 'wx-image'
      }
      // 添加的代码结束

      // handle IE svg bug
      /* istanbul ignore if */
      if (isIE && ns === 'svg') {
        attrs = guardIESVGBug(attrs);
      }
  // 下略

修改后,image标签就会被自动转化了。最后别忘了修改mainH5.js:

Vue.mixin({
  components: {
    wxImage // 修改这里
  }
})

这样就完成了image标签的基本适配,其他组件用相似的思路就行了。
这里再举例一个scroll-view的简单适配:

<template>
  <div :class="containerStyle">
    <slot></slot>
  </div>
</template>

<script>
  export default {
    name: "scroll-view",
    props: {
      scrollX: {
        type: Boolean,
        default: false
      },
      scrollY: {
        type: Boolean,
        default: false
      }
    },
    computed: {
      containerStyle () {
        if (this.scrollX) {
          return 'sv_x'
        }
        if (this.scrollY) {
          return 'sv_y'
        }
        return ''
      }
    }
  }
</script>

<style scoped>
  .sv_x {
    overflow-x: auto;
    overflow-y: hidden;
    display: flex;
    flex-direction: row;
  }

  .sv_y {
    overflow-x: hidden;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    flex-wrap: nowrap;
  }
</style>

常见的组件如view、image、scroll-view、text、swiper等适配后,至少大部分布局显示是不成问题的。

适配单位

小程序一般使用rpx作为单位开发,而rpx在浏览器上无法识别。如何在尽可能不修改项目代码的同时做到适配呢?
一般来说,项目代码中用到rpx的有这么几种情况:
1 style内联

<div style="width: 750rpx; height: 50rpx;"></div>

2 style内联(动态)

<div :style="{width: divWidth + diffWidth + 'rpx'}"></div>

3 style标签中

<style>
.container {
	width: 750rpx;
}
</style>

4 代码中

let divStyle = {width: divWidth + diffWidth + 'rpx'}

首先,对于2、4情况,想要自动实现只能通过编写脚本进行文本替换,然而实际情况复杂,所以写脚本是吃力不讨好的,实际开发中尽量避免,如果用到这种动态情况,用vw这种兼容更强的单位就好。对于1、3情况,是有办法解决的。
修改node_modules/lib/loader.js:

processCss(content, map, {
		mode: moduleMode ? "local" : "global",
		from: loaderUtils.getRemainingRequest(this).split("!").pop(),
		to: loaderUtils.getCurrentRequest(this).split("!").pop(),
		query: query,
		resolve: resolve,
		minimize: this.minimize,
		loaderContext: this,
		sourceMap: sourceMap
	}, function(err, result) {
		if(err) return callback(err);

		var cssAsString = JSON.stringify(result.source);
		// 这里添加一行,替换rpx为px
    	cssAsString = cssAsString.replace(/rpx/g, 'px')

		// for importing CSS
		var importUrlPrefix = getImportPrefix(this, query);
		// 下略

这样style标签中的rpx被自动转化了。我们只需要将预览窗口的宽度定为750px,即可达到适配目的。预览窗口本身可以scale缩放,来适应浏览器的窗口大小。

另外,对于情况1,我们可以写一个类似px2rpx-loader的插件来实现转换,但是更简单粗暴的方法是直接修改node_modules/px2rpx/bin/px2rpx.js,将其实现从"px->rpx"改为"rpx->px":

#!/usr/bin/env node

var program = require('commander');
var pkg = require('../package.json');
var Px2rpx = require('../index');
var chalk = require('chalk');
var path = require('path');
var fs = require('fs-extra');


// string to variables of proper type(thanks to zepto)
function deserializeValue(value) {
  var num;
  try {
    return value ?
      value == "true" || value == true ||
      (value == "false" || value == false ? false :
        value == "null" ? null :
        !/^0/.test(value) && !isNaN(num = Number(value)) ? num :
        /^[\[\{]/.test(value) ? JSON.parse(value) :
        value)
      : value;
  } catch (e) {
    return value;
  }
}

function saveFile(filePath, content) {
  fs.createFileSync(filePath);
  fs.writeFileSync(filePath, content, {encoding: 'utf8'});
  console.log(chalk.green.bold('[Success]: ') + filePath);
}


program.version(pkg.version)
  .option('-u, --rpxUnit [value]', 'set `rpx` unit value (default: 75)', 75)
  .option('-x, --threeVersion [value]', 'whether to generate @1x, @2x and @3x version stylesheet (default: false)', false)
  .option('-r, --rpxVersion [value]', 'whether to generate rpx version stylesheet (default: true)', true)
  .option('-b, --baseDpr [value]', 'set base device pixel ratio (default: 2)', 2)
  .option('-p, --rpxPrecision [value]', 'set rpx value precision (default: 6)', 6)
  .option('-o, --output [path]', 'the output file dirname')
  .parse(process.argv);

if (!program.args.length) {
  console.log(chalk.yellow.bold('[Info]: ') + 'No files to process!');
  return false;
}

var config = {
  rpxUnit: deserializeValue(program.rpxUnit),
  threeVersion: deserializeValue(program.threeVersion),
  rpxVersion: deserializeValue(program.rpxVersion),
  baseDpr: deserializeValue(program.baseDpr),
  rpxPrecision: deserializeValue(program.rpxPrecision)
};

var px2rpxIns = new Px2rpx(config);

program.args.forEach(function (filePath) {

  if (path.extname(filePath) !== '.css') {
    return;
  }

  var cssText = fs.readFileSync(filePath, {encoding: 'utf8'});
  var outputPath = program.output || path.dirname(filePath);
  var fileName = path.basename(filePath);

  // generate @1x, @2x and @3x version stylesheet
  if (config.threeVersion) {
    for (var dpr = 1; dpr <= 3; dpr++) {
      var newCssText = px2rpxIns.generateThree(cssText, dpr);
      var newFileName = fileName.replace(/(.debug)?.css/, dpr + 'x.debug.css');
      var newFilepath = path.join(outputPath, newFileName);
      saveFile(newFilepath, newCssText);
    }
  }

  // generate rpx version stylesheet
  if (config.rpxVersion) {
    var newCssText = px2rpxIns.generaterpx(cssText);
    var newFileName = fileName.replace(/(.debug)?.css/, '.debug.css');
    var newFilepath = path.join(outputPath, newFileName);
    saveFile(newFilepath, newCssText);
  }
});

结束语

本文提供了一个小程序在浏览器端运行的思路,其中适配组件和api是工作量大的地方,但由于一些原因,我不会在Github放demo,想要真正商业级实现这个需求就看自身了。

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