说,您有一些要在CSS和JS代码之间共享的变量:
vars.js
:
module.exports = {
'body-margin': '100px',
};
style.css
:
body {
margin: var(--body-margin);
}
entry.js
:
var vars = require('./vars.js');
require('./style.css');
document.body.appendChild(
document.createTextNode(vars['body-margin']));
我使用postcss-cssnext
/postcss-custom-properties
插件来做到这一点:
webpack.config.js
:
var HtmlWebpackPlugin = require('html-webpack-plugin');
module.exports = {
entry: './entry.js',
output: {
filename: 'bundle.js',
},
module: {
rules: [{
test: /.css$/,
use: [
'style-loader',
'css-loader',
{loader: 'postcss-loader',
options: {
plugins: [
require('postcss-cssnext')({
features: {
customProperties: {
variables: require('./vars.js'),
},
},
}),
],
}},
],
}],
},
plugins: [new HtmlWebpackPlugin()],
};
但是,当我运行webpack-dev-server
并更改vars.js
中的变量时,JavaScript代码会注意更改,但CSS代码不会。有没有办法来解决这个问题?使CSS反映更改,而无需重新启动webpack-dev-server
。P.S.我并没有使用postcss
/cssnext
/postcss-custom-properties
共享变量(如果有的话)。
package.json
:
{
"dependencies": {
"css-loader": "^0.28.7",
"html-webpack-plugin": "^2.30.1",
"postcss-cssnext": "^3.0.2",
"postcss-loader": "^2.0.6",
"style-loader": "^0.18.2",
"webpack": "^3.6.0",
"webpack-dev-server": "^2.8.2"
}
}
我想出了以下方法来修复它:
diff --git a/webpack.config.js b/webpack.config.js
index 0046862..73c75a1 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -1,5 +1,20 @@
+var path = require('path');
var HtmlWebpackPlugin = require('html-webpack-plugin');
+var varsFile = './vars.js';
+
+var postcssCssnextFeatures = require('postcss-cssnext/lib/features').default;
+var customPropertiesPlugin;
+postcssCssnextFeatures.customProperties = (options) => {
+ customPropertiesPlugin = require('postcss-custom-properties')(options);
+ return customPropertiesPlugin;
+};
+
+function getVars() {
+ delete require.cache[require.resolve(varsFile)];
+ return require(varsFile);
+}
+
module.exports = {
entry: './entry.js',
output: {
@@ -17,7 +32,7 @@ module.exports = {
require('postcss-cssnext')({
features: {
customProperties: {
- variables: require('./vars.js'),
+ variables: getVars(),
},
},
}),
@@ -26,5 +41,22 @@ module.exports = {
],
}],
},
- plugins: [new HtmlWebpackPlugin()],
+ plugins: [
+ new HtmlWebpackPlugin(),
+ {apply: function(compiler) {
+ compiler.plugin('compilation', function(compilation) {
+ compilation.plugin('succeed-module', function(module) {
+ if (module.resource
+ && module.resource.indexOf(path.resolve('node_modules')) == -1
+ && path.extname(module.resource) == '.css'
+ && module.fileDependencies.indexOf(varsFile) == -1 // extract-text-webpack-plugin, for instance, makes webpack build modules twice
+ ) {
+ module.fileDependencies.push(varsFile);
+ }
+ });
+ });
+ compiler.plugin('invalid', function(filename) {
+ customPropertiesPlugin.setVariables(getVars());
+ });
+ }},
+ ],
};
我遇到的问题:
postcss-custom-properties
插件用setVariables
方法返回一个对象,可用于更新vars。但是postcss
/cssnext
不能提供访问该对象的简便方法。因此,我猴子补丁postcss-cssnext/lib/features.js
,拦截对象并放入customPropertiesPlugin
变量。我不能简单地需要
vars.js
。内容被缓存。
如果您知道任何简单的方法,如果您告诉我,我会很感激。也许只是一个主意。或一种改善我的解决方案的方法。理想情况下,我猜必须有postcss
插件允许@import
JavaScript文件。