编译后修改文件的webpack插件 [英] Webpack plugin to modify files after compilation

问题描述

我正在编写一个 Webpack 插件，该插件应该用 Webpack 生成的 CSS 文件列表替换部分 JS 代码.对这段 JS 代码进行成像:

I am writing a Webpack plugin that should replace a part of the JS code with a list of Webpack's generated CSS files. Imaging this JS code:

ReactWebComponent.create(<App />, 'react-web-component', { injectReactWebComponent: true });

我想用

injectReactWebComponent: '<link href="static/css/main.cacbacc7.css" rel="stylesheet">'

虽然那个链接标签是由 Webpack 生成的文件.

While that link tag is a file generated by Webpack.

我的(工作)代码如下:

My (kind of working) code for this goes as follows:

ReactWebComponent.prototype.apply = function(compiler) {
  compiler.plugin('emit', function(compilation, callback) {
    const cssFiles = Object.keys(compilation.assets)
        .filter(fileName => /\.css$/.test(fileName));

    const jsFiles = Object.keys(compilation.assets)
        .filter(fileName => /\.js$/.test(fileName));

    const cssLinkTagsAsString = cssFiles
        .map(fileName => `<link href="${fileName}" rel="stylesheet">`)
        .join('');

    jsFiles.forEach(fileName => {
      compilation.assets[fileName].children.forEach(child => {
        if (child._value) {
          child._value = child._value.replace(/injectReactWebComponent\s*:\s*true/g, `injectReactWebComponent: \'${cssLinkTagsAsString}\'`);
        }
      });
    });

    callback();
  });
};

module.exports = ReactWebComponent;

看我做的那一行

child._value = child._value.replace(...)

我坦率地重写了来源.

但这对我来说似乎不合适.我正在转换的代码似乎已经生成，不应再转换.我也很确定我用这个破坏了源映射.

But this does not seem right for me. It seems the code I am transforming has already been generated and not ought to be transformed anymore. I am also pretty sure I am breaking the source maps with this.

所以我想知道，实现我正在做的事情的合适方法是什么?

So I am wondering, what would be an appropriate way to achieve what I am doing?

我猜测转换部分我应该使用 loader，但是加载器不知道生成的文件名，或者他们知道吗?

I am guessing for the transformation part I should use a loader, but then loaders do not know about the generated file names, or do they?

任何帮助将不胜感激！

推荐答案

看起来这种事情很简单，可以由加载器处理，其中有多个(有些比其他更好):

It appears this sort of thing is simple enough to be handled by loaders, of which there are multiple (some better than others):

https://www.npmjs.com/package/string-replace-loader

https://www.npmjs.com/package/regexp-replace-loader

https://www.npmjs.com/package/replace-loader

如果你想制作自己的插件来做到这一点(我只是通过这个过程来做一些比正则表达式替换更复杂的事情)，我基本上可以从这三个页面中拼凑出我的解决方案:

If you want to go about making your own plugin to do this (I just went through the process to do something a bit more sophisticated than just regex replacement), I was able to piece my solution together from basically these three pages:

https://github.com/webpack/webpack/blob/master/lib/BannerPlugin.js

https://webpack.js.org/api/plugins/compilation/#optimize-chunk-assets-chunks-chunk-async

https://github.com/webpack/webpack-sources

这篇关于编译后修改文件的webpack插件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！