javascript - 使用 webpack 从 MDL 加载特定组件

Question

我只想在我的项目中使用 MDL 的布局组件。

因此，在我的 app.css 文件中，我导入以下内容:

@import url('~material-design-lite/src/layout/_layout.scss');

在构建过程中我收到以下错误:

ERROR in ./~/css-loader!./~/material-design-lite/src/layout/_layout.scss
Module not found: Error: Cannot resolve 'file' or 'directory' ../variables in /Users/Mitch/Documents/project/web/node_modules/material-design-lite/src/layout
 @ ./~/css-loader!./~/material-design-lite/src/layout/_layout.scss 3:10-66

ERROR in ./~/css-loader!./~/material-design-lite/src/layout/_layout.scss
Module not found: Error: Cannot resolve 'file' or 'directory' ../mixins in /Users/Mitch/Documents/project/web/node_modules/material-design-lite/src/layout
 @ ./~/css-loader!./~/material-design-lite/src/layout/_layout.scss 4:10-63

_layout.sccs 以这些行开头

@import "../variables";
@import "../mixins";

知道我可能做错了什么吗？

我的webpack.config.js的相关部分:

const PATHS = {
    node_modules: path.resolve(__dirname, 'node_modules'),
    build: path.join(__dirname, 'public', 'build'),
    js: path.resolve(__dirname, 'public', 'js'),
    css: path.resolve(__dirname, 'public', 'css'),
};

...
resolve: {
    root: [
        path.resolve(__dirname),
        PATHS.node_modules,
        PATHS.js,
        PATHS.css
    ],
    ...
    extensions: ['', '.js', '.jsx', '.json', '.css', '.scss']
},
module: {
    loaders: [
        {
            test: /\.css$/,
            loader: ExtractTextPlugin.extract('style-loader', 'css-loader')
        },
        {
            test: /\.scss$/,
            loader: ExtractTextPlugin.extract('style', 'css?modules!sass')
        },
        {
            test: /\.png$/,
            loader: 'url-loader?limit=100000'
        },
        {
            test: /\.jpg$/,
            loader: 'file-loader'
        },
        {
            test: /\.gif$/,
            loader: 'file-loader'
        },
        {
            test: /\.(woff|woff2)(\?v=\d+\.\d+\.\d+)?$/,
            loader: 'url?limit=10000&mimetype=application/font-woff'
        },
        {
            test: /\.ttf(\?v=\d+\.\d+\.\d+)?$/,
            loader: 'url?limit=10000&mimetype=application/octet-stream'
        },
        {
            test: /\.eot(\?v=\d+\.\d+\.\d+)?$/,
            loader: 'file'
        },
        {
            test: /\.svg(\?v=\d+\.\d+\.\d+)?$/,
            loader: 'url?limit=10000&mimetype=image/svg+xml'
        },
        {
            test: /\.js$/,
            exclude: /node_modules/,
            loader: 'babel-loader',
            query: {
                presets: ['es2015']
            }
        }
    ]
}
...

相关依赖:

...
"devDependencies": {
    "babel-core": "^6.14.0",
    "babel-loader": "^6.2.5",
    "babel-preset-es2015": "^6.14.0",
    "css-loader": "^0.25.0",
    "eslint": "^3.6.1",
    "extract-text-webpack-plugin": "^1.0.1",
    "file-loader": "^0.9.0",
    "node-sass": "^3.10.1",
    "sass-loader": "^4.0.2",
    "style-loader": "^0.13.1",
    "url-loader": "^0.5.7",
    "webpack": "^1.13.2",
    "webpack-validator": "^2.2.7"
}
...

更新

我尝试@import url('~material-design-lite/src/material-design-lite.scss');，因为这不是部分的，在我将其修改为只导入布局组件。

现在我收到以下错误:

ERROR in ./~/css-loader!./~/material-design-lite/src/material-design-lite.scss
Module build failed: Unknown word (19:1)

  17 | /* Material Design Lite */
  18 | 
> 19 | // Variables and mixins
     | ^
  20 | @import "variables";
  21 | @import "mixins";
  22 | 

 @ ./~/css-loader!./public/css/app.css 3:10-114

评论失败。我不知道如何解决这个问题，我尝试使用 postcss 和 postcss-scss 加载器和 postcss-strip-inline-comments 插件徒劳无功;旧的错误只是被新的错误所取代。

Answer 1

您的示例中的实际问题是您像这样导入 MDL

@import url('~material-design-lite/src/layout/_layout.scss');

而不是

@import '~material-design-lite/src/layout/_layout.scss';

第一个被 sass-loader 忽略(因为 SASS 没有 url() 导入)并将由 css-loader 处理。然而，css-loader 不会自动将 .scss 扩展为 variables。这就是您收到这些“找不到模块”错误的原因。