浅谈webpack编译vue项目生成的代码探索(4)

/* 6 */
/***/
(function (module, __webpack_exports__, __webpack_require__) {

  "use strict";

  // 返回具体 App.vue 中 的script 中的代码
  var __WEBPACK_IMPORTED_MODULE_0__babel_loader_node_modules_vue_loader_lib_selector_type_script_index_0_App_vue__ = __webpack_require__(13);

  // 把App.vue 的 template 解析为一堆 vue render 函数。
  var __WEBPACK_IMPORTED_MODULE_1__node_modules_vue_loader_lib_template_compiler_index_id_data_v_66ce2159_hasScoped_false_buble_transforms_node_modules_vue_loader_lib_selector_type_template_index_0_App_vue__ = __webpack_require__(14);

  // 注入vue文件里写入的css函数
  function injectStyle(ssrContext) {
    // 由此可知7号模块是编译并插入vue中的css到DOM上的
    __webpack_require__(7)
  }
  // 12号模块用于输出components渲染函数
  var normalizeComponent = __webpack_require__(12)
  /* script */

  /* template */

  /* template functional */
  var __vue_template_functional__ = false
  /* styles */
  var __vue_styles__ = injectStyle
  /* scopeId */
  var __vue_scopeId__ = null
  /* moduleIdentifier (server only) */
  var __vue_module_identifier__ = null

  // 编译模块，混杂template和script。
  var Component = normalizeComponent(
    __WEBPACK_IMPORTED_MODULE_0__babel_loader_node_modules_vue_loader_lib_selector_type_script_index_0_App_vue__["a" /* default */ ],
    __WEBPACK_IMPORTED_MODULE_1__node_modules_vue_loader_lib_template_compiler_index_id_data_v_66ce2159_hasScoped_false_buble_transforms_node_modules_vue_loader_lib_selector_type_template_index_0_App_vue__["a" /* default */ ],
    __vue_template_functional__,
    __vue_styles__,
    __vue_scopeId__,
    __vue_module_identifier__
  )

  /* harmony default export */
  __webpack_exports__["a"] = (Component.exports);


  /***/
}),

/* 7 */

/***/
(function (module, exports, __webpack_require__) {

  // style-loader: Adds some css to the DOM by adding a <style> tag

  // load the styles
  var content = __webpack_require__(8);
  if (typeof content === 'string') content = [
    [module.i, content, '']
  ];
  if (content.locals) module.exports = content.locals;
  // add the styles to the DOM
  var update = __webpack_require__(10)("15459d21", content, true);

  /***/
}),
/* 8 */
/***/
(function (module, exports, __webpack_require__) {

  // css-loader 用于做css的sourceMap
  exports = module.exports = __webpack_require__(9)(undefined);
  // imports


  // module
  // 这就是 App.vue 文件中 style 里的的 css
  exports.push([module.i, "#app{font-family:Avenir,Helvetica,Arial,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;text-align:center;color:#2c3e50;margin-top:60px}h1,h2{font-weight:400}ul{list-style-type:none;padding:0}li{display:inline-block;margin:0 10px}a{color:#42b983}", ""]);

  // exports


  /***/
}),
/* 9 */
/***/
(function (module, exports) {
  // css base code, injected by the css-loader
  module.exports = function (useSourceMap) {
    // 省略代码...
  }
}),
/* 10 */
/***/
(function (module, exports, __webpack_require__) {
  /*
    MIT License http://www.opensource.org/licenses/mit-license.php
    Author Tobias Koppers @sokra
    Modified by Evan You @yyx990803
  */

  // ...太长只贴了关键步骤，总之关键的函数就是这些
  var hasDocument = typeof document !== 'undefined'
  // ...
  var listToStyles = __webpack_require__(11)
  // ...
  var head = hasDocument && (document.head || document.getElementsByTagName('head')[0])


  // ...
  module.exports = function (parentId, list, _isProduction) {

    // ...
    var styles = listToStyles(parentId, list)
    addStylesToDom(styles)

    return function update (newList) {
      // ...
    }
  }

  function addStylesToDom (styles /* Array<StyleObject> */) {
    for (var i = 0; i < styles.length; i++) {
      // ...
      domStyle.parts.push(addStyle(item.parts[j]))
      // ....
    }
  }

  // 总之先调用了addStylesToDom，接着是addStyle，再是createStyleElement插入样式到head中。
  function createStyleElement () {
  var styleElement = document.createElement('style')
  styleElement.type = 'text/css'
  head.appendChild(styleElement)
  return styleElement
  }

  function addStyle (obj /* StyleObjectPart */) {
    // ...
    styleElement = createStyleElement()
    // ...
  }

  /***/
}),
/* 11 */
/***/
(function (module, exports) {

  /**
   * Translates the list format produced by css-loader into something
   * easier to manipulate.
   */
  module.exports = function listToStyles(parentId, list) {
    var styles = []
    var newStyles = {}
    for (var i = 0; i < list.length; i++) {
      var item = list[i]
      var id = item[0]
      var css = item[1]
      var media = item[2]
      var sourceMap = item[3]
      var part = {
        id: parentId + ':' + i,
        css: css,
        media: media,
        sourceMap: sourceMap
      }
      if (!newStyles[id]) {
        styles.push(newStyles[id] = {
          id: id,
          parts: [part]
        })
      } else {
        newStyles[id].parts.push(part)
      }
    }
    return styles
  }


  /***/
}),