| [6a3a178] | 1 | <div align="center">
|
|---|
| 2 | <a href="https://github.com/webpack/webpack">
|
|---|
| 3 | <img width="200" height="200" src="https://webpack.js.org/assets/icon-square-big.svg">
|
|---|
| 4 | </a>
|
|---|
| 5 | </div>
|
|---|
| 6 |
|
|---|
| 7 | [![npm][npm]][npm-url]
|
|---|
| 8 | [![node][node]][node-url]
|
|---|
| 9 | [![deps][deps]][deps-url]
|
|---|
| 10 | [![tests][tests]][tests-url]
|
|---|
| 11 | [![cover][cover]][cover-url]
|
|---|
| 12 | [![chat][chat]][chat-url]
|
|---|
| 13 | [![size][size]][size-url]
|
|---|
| 14 |
|
|---|
| 15 | # less-loader
|
|---|
| 16 |
|
|---|
| 17 | A Less loader for webpack. Compiles Less to CSS.
|
|---|
| 18 |
|
|---|
| 19 | ## Getting Started
|
|---|
| 20 |
|
|---|
| 21 | To begin, you'll need to install `less` and `less-loader`:
|
|---|
| 22 |
|
|---|
| 23 | ```console
|
|---|
| 24 | $ npm install less less-loader --save-dev
|
|---|
| 25 | ```
|
|---|
| 26 |
|
|---|
| 27 | Then add the loader to your `webpack` config. For example:
|
|---|
| 28 |
|
|---|
| 29 | **webpack.config.js**
|
|---|
| 30 |
|
|---|
| 31 | ```js
|
|---|
| 32 | module.exports = {
|
|---|
| 33 | module: {
|
|---|
| 34 | rules: [
|
|---|
| 35 | {
|
|---|
| 36 | test: /\.less$/i,
|
|---|
| 37 | loader: [
|
|---|
| 38 | // compiles Less to CSS
|
|---|
| 39 | "style-loader",
|
|---|
| 40 | "css-loader",
|
|---|
| 41 | "less-loader",
|
|---|
| 42 | ],
|
|---|
| 43 | },
|
|---|
| 44 | ],
|
|---|
| 45 | },
|
|---|
| 46 | };
|
|---|
| 47 | ```
|
|---|
| 48 |
|
|---|
| 49 | And run `webpack` via your preferred method.
|
|---|
| 50 |
|
|---|
| 51 | ## Options
|
|---|
| 52 |
|
|---|
| 53 | | Name | Type | Default | Description |
|
|---|
| 54 | | :---------------------------------------: | :------------------: | :----------------------: | :----------------------------------------------------- |
|
|---|
| 55 | | **[`lessOptions`](#lessoptions)** | `{Object\|Function}` | `{ relativeUrls: true }` | Options for Less. |
|
|---|
| 56 | | **[`additionalData`](#additionalData)** | `{String\|Function}` | `undefined` | Prepends/Appends `Less` code to the actual entry file. |
|
|---|
| 57 | | **[`sourceMap`](#sourcemap)** | `{Boolean}` | `compiler.devtool` | Enables/Disables generation of source maps. |
|
|---|
| 58 | | **[`webpackImporter`](#webpackimporter)** | `{Boolean}` | `true` | Enables/Disables the default Webpack importer. |
|
|---|
| 59 | | **[`implementation`](#implementation)** | `{Object\|String}` | `less` | Setup Less implementation to use. |
|
|---|
| 60 |
|
|---|
| 61 | ### `lessOptions`
|
|---|
| 62 |
|
|---|
| 63 | Type: `Object|Function`
|
|---|
| 64 | Default: `{ relativeUrls: true }`
|
|---|
| 65 |
|
|---|
| 66 | You can pass any Less specific options to the `less-loader` through the `lessOptions` property in the [loader options](https://webpack.js.org/configuration/module/#rule-options-rule-query). See the [Less documentation](http://lesscss.org/usage/#command-line-usage-options) for all available options in dash-case. Since we're passing these options to Less programmatically, you need to pass them in camelCase here:
|
|---|
| 67 |
|
|---|
| 68 | #### `Object`
|
|---|
| 69 |
|
|---|
| 70 | Use an object to pass options through to Less.
|
|---|
| 71 |
|
|---|
| 72 | **webpack.config.js**
|
|---|
| 73 |
|
|---|
| 74 | ```js
|
|---|
| 75 | module.exports = {
|
|---|
| 76 | module: {
|
|---|
| 77 | rules: [
|
|---|
| 78 | {
|
|---|
| 79 | test: /\.less$/i,
|
|---|
| 80 | use: [
|
|---|
| 81 | {
|
|---|
| 82 | loader: "style-loader",
|
|---|
| 83 | },
|
|---|
| 84 | {
|
|---|
| 85 | loader: "css-loader",
|
|---|
| 86 | },
|
|---|
| 87 | {
|
|---|
| 88 | loader: "less-loader",
|
|---|
| 89 | options: {
|
|---|
| 90 | lessOptions: {
|
|---|
| 91 | strictMath: true,
|
|---|
| 92 | },
|
|---|
| 93 | },
|
|---|
| 94 | },
|
|---|
| 95 | ],
|
|---|
| 96 | },
|
|---|
| 97 | ],
|
|---|
| 98 | },
|
|---|
| 99 | };
|
|---|
| 100 | ```
|
|---|
| 101 |
|
|---|
| 102 | #### `Function`
|
|---|
| 103 |
|
|---|
| 104 | Allows setting the options passed through to Less based off of the loader context.
|
|---|
| 105 |
|
|---|
| 106 | ```js
|
|---|
| 107 | module.exports = {
|
|---|
| 108 | module: {
|
|---|
| 109 | rules: [
|
|---|
| 110 | {
|
|---|
| 111 | test: /\.less$/i,
|
|---|
| 112 | use: [
|
|---|
| 113 | "style-loader",
|
|---|
| 114 | "css-loader",
|
|---|
| 115 | {
|
|---|
| 116 | loader: "less-loader",
|
|---|
| 117 | options: {
|
|---|
| 118 | lessOptions: (loaderContext) => {
|
|---|
| 119 | // More information about available properties https://webpack.js.org/api/loaders/
|
|---|
| 120 | const { resourcePath, rootContext } = loaderContext;
|
|---|
| 121 | const relativePath = path.relative(rootContext, resourcePath);
|
|---|
| 122 |
|
|---|
| 123 | if (relativePath === "styles/foo.less") {
|
|---|
| 124 | return {
|
|---|
| 125 | paths: ["absolute/path/c", "absolute/path/d"],
|
|---|
| 126 | };
|
|---|
| 127 | }
|
|---|
| 128 |
|
|---|
| 129 | return {
|
|---|
| 130 | paths: ["absolute/path/a", "absolute/path/b"],
|
|---|
| 131 | };
|
|---|
| 132 | },
|
|---|
| 133 | },
|
|---|
| 134 | },
|
|---|
| 135 | ],
|
|---|
| 136 | },
|
|---|
| 137 | ],
|
|---|
| 138 | },
|
|---|
| 139 | };
|
|---|
| 140 | ```
|
|---|
| 141 |
|
|---|
| 142 | ### `additionalData`
|
|---|
| 143 |
|
|---|
| 144 | Type: `String|Function`
|
|---|
| 145 | Default: `undefined`
|
|---|
| 146 |
|
|---|
| 147 | Prepends `Less` code before the actual entry file.
|
|---|
| 148 | In this case, the `less-loader` will not override the source but just **prepend** the entry's content.
|
|---|
| 149 |
|
|---|
| 150 | This is especially useful when some of your Less variables depend on the environment:
|
|---|
| 151 |
|
|---|
| 152 | > ℹ Since you're injecting code, this will break the source mappings in your entry file. Often there's a simpler solution than this, like multiple Less entry files.
|
|---|
| 153 |
|
|---|
| 154 | #### `String`
|
|---|
| 155 |
|
|---|
| 156 | ```js
|
|---|
| 157 | module.exports = {
|
|---|
| 158 | module: {
|
|---|
| 159 | rules: [
|
|---|
| 160 | {
|
|---|
| 161 | test: /\.less$/i,
|
|---|
| 162 | use: [
|
|---|
| 163 | "style-loader",
|
|---|
| 164 | "css-loader",
|
|---|
| 165 | {
|
|---|
| 166 | loader: "less-loader",
|
|---|
| 167 | options: {
|
|---|
| 168 | additionalData: `@env: ${process.env.NODE_ENV};`,
|
|---|
| 169 | },
|
|---|
| 170 | },
|
|---|
| 171 | ],
|
|---|
| 172 | },
|
|---|
| 173 | ],
|
|---|
| 174 | },
|
|---|
| 175 | };
|
|---|
| 176 | ```
|
|---|
| 177 |
|
|---|
| 178 | #### `Function`
|
|---|
| 179 |
|
|---|
| 180 | ##### Sync
|
|---|
| 181 |
|
|---|
| 182 | ```js
|
|---|
| 183 | module.exports = {
|
|---|
| 184 | module: {
|
|---|
| 185 | rules: [
|
|---|
| 186 | {
|
|---|
| 187 | test: /\.less$/i,
|
|---|
| 188 | use: [
|
|---|
| 189 | "style-loader",
|
|---|
| 190 | "css-loader",
|
|---|
| 191 | {
|
|---|
| 192 | loader: "less-loader",
|
|---|
| 193 | options: {
|
|---|
| 194 | additionalData: (content, loaderContext) => {
|
|---|
| 195 | // More information about available properties https://webpack.js.org/api/loaders/
|
|---|
| 196 | const { resourcePath, rootContext } = loaderContext;
|
|---|
| 197 | const relativePath = path.relative(rootContext, resourcePath);
|
|---|
| 198 |
|
|---|
| 199 | if (relativePath === "styles/foo.less") {
|
|---|
| 200 | return "@value: 100px;" + content;
|
|---|
| 201 | }
|
|---|
| 202 |
|
|---|
| 203 | return "@value: 200px;" + content;
|
|---|
| 204 | },
|
|---|
| 205 | },
|
|---|
| 206 | },
|
|---|
| 207 | ],
|
|---|
| 208 | },
|
|---|
| 209 | ],
|
|---|
| 210 | },
|
|---|
| 211 | };
|
|---|
| 212 | ```
|
|---|
| 213 |
|
|---|
| 214 | ##### Async
|
|---|
| 215 |
|
|---|
| 216 | ```js
|
|---|
| 217 | module.exports = {
|
|---|
| 218 | module: {
|
|---|
| 219 | rules: [
|
|---|
| 220 | {
|
|---|
| 221 | test: /\.less$/i,
|
|---|
| 222 | use: [
|
|---|
| 223 | "style-loader",
|
|---|
| 224 | "css-loader",
|
|---|
| 225 | {
|
|---|
| 226 | loader: "less-loader",
|
|---|
| 227 | options: {
|
|---|
| 228 | additionalData: async (content, loaderContext) => {
|
|---|
| 229 | // More information about available properties https://webpack.js.org/api/loaders/
|
|---|
| 230 | const { resourcePath, rootContext } = loaderContext;
|
|---|
| 231 | const relativePath = path.relative(rootContext, resourcePath);
|
|---|
| 232 |
|
|---|
| 233 | if (relativePath === "styles/foo.less") {
|
|---|
| 234 | return "@value: 100px;" + content;
|
|---|
| 235 | }
|
|---|
| 236 |
|
|---|
| 237 | return "@value: 200px;" + content;
|
|---|
| 238 | },
|
|---|
| 239 | },
|
|---|
| 240 | },
|
|---|
| 241 | ],
|
|---|
| 242 | },
|
|---|
| 243 | ],
|
|---|
| 244 | },
|
|---|
| 245 | };
|
|---|
| 246 | ```
|
|---|
| 247 |
|
|---|
| 248 | ### `sourceMap`
|
|---|
| 249 |
|
|---|
| 250 | Type: `Boolean`
|
|---|
| 251 | Default: depends on the `compiler.devtool` value
|
|---|
| 252 |
|
|---|
| 253 | By default generation of source maps depends on the [`devtool`](https://webpack.js.org/configuration/devtool/) option. All values enable source map generation except `eval` and `false` value.
|
|---|
| 254 |
|
|---|
| 255 | **webpack.config.js**
|
|---|
| 256 |
|
|---|
| 257 | ```js
|
|---|
| 258 | module.exports = {
|
|---|
| 259 | module: {
|
|---|
| 260 | rules: [
|
|---|
| 261 | {
|
|---|
| 262 | test: /\.less$/i,
|
|---|
| 263 | use: [
|
|---|
| 264 | "style-loader",
|
|---|
| 265 | {
|
|---|
| 266 | loader: "css-loader",
|
|---|
| 267 | options: {
|
|---|
| 268 | sourceMap: true,
|
|---|
| 269 | },
|
|---|
| 270 | },
|
|---|
| 271 | {
|
|---|
| 272 | loader: "less-loader",
|
|---|
| 273 | options: {
|
|---|
| 274 | sourceMap: true,
|
|---|
| 275 | },
|
|---|
| 276 | },
|
|---|
| 277 | ],
|
|---|
| 278 | },
|
|---|
| 279 | ],
|
|---|
| 280 | },
|
|---|
| 281 | };
|
|---|
| 282 | ```
|
|---|
| 283 |
|
|---|
| 284 | ### `webpackImporter`
|
|---|
| 285 |
|
|---|
| 286 | Type: `Boolean`
|
|---|
| 287 | Default: `true`
|
|---|
| 288 |
|
|---|
| 289 | Enables/Disables the default `webpack` importer.
|
|---|
| 290 |
|
|---|
| 291 | This can improve performance in some cases. Use it with caution because aliases and `@import` at-rules starting with `~` will not work.
|
|---|
| 292 |
|
|---|
| 293 | **webpack.config.js**
|
|---|
| 294 |
|
|---|
| 295 | ```js
|
|---|
| 296 | module.exports = {
|
|---|
| 297 | module: {
|
|---|
| 298 | rules: [
|
|---|
| 299 | {
|
|---|
| 300 | test: /\.less$/i,
|
|---|
| 301 | use: [
|
|---|
| 302 | "style-loader",
|
|---|
| 303 | "css-loader",
|
|---|
| 304 | {
|
|---|
| 305 | loader: "less-loader",
|
|---|
| 306 | options: {
|
|---|
| 307 | webpackImporter: false,
|
|---|
| 308 | },
|
|---|
| 309 | },
|
|---|
| 310 | ],
|
|---|
| 311 | },
|
|---|
| 312 | ],
|
|---|
| 313 | },
|
|---|
| 314 | };
|
|---|
| 315 | ```
|
|---|
| 316 |
|
|---|
| 317 | ### `implementation`
|
|---|
| 318 |
|
|---|
| 319 | Type: `Object | String`
|
|---|
| 320 |
|
|---|
| 321 | > ⚠ less-loader compatible with Less 3 and 4 versions
|
|---|
| 322 |
|
|---|
| 323 | The special `implementation` option determines which implementation of Less to use. Overrides the locally installed `peerDependency` version of `less`.
|
|---|
| 324 |
|
|---|
| 325 | **This option is only really useful for downstream tooling authors to ease the Less 3-to-4 transition.**
|
|---|
| 326 |
|
|---|
| 327 | #### Object
|
|---|
| 328 |
|
|---|
| 329 | **webpack.config.js**
|
|---|
| 330 |
|
|---|
| 331 | ```js
|
|---|
| 332 | module.exports = {
|
|---|
| 333 | module: {
|
|---|
| 334 | rules: [
|
|---|
| 335 | {
|
|---|
| 336 | test: /\.less$/i,
|
|---|
| 337 | use: [
|
|---|
| 338 | "style-loader",
|
|---|
| 339 | "css-loader",
|
|---|
| 340 | {
|
|---|
| 341 | loader: "less-loader",
|
|---|
| 342 | options: {
|
|---|
| 343 | implementation: require("less"),
|
|---|
| 344 | },
|
|---|
| 345 | },
|
|---|
| 346 | ],
|
|---|
| 347 | },
|
|---|
| 348 | ],
|
|---|
| 349 | },
|
|---|
| 350 | };
|
|---|
| 351 | ```
|
|---|
| 352 |
|
|---|
| 353 | #### String
|
|---|
| 354 |
|
|---|
| 355 | **webpack.config.js**
|
|---|
| 356 |
|
|---|
| 357 | ```js
|
|---|
| 358 | module.exports = {
|
|---|
| 359 | module: {
|
|---|
| 360 | rules: [
|
|---|
| 361 | {
|
|---|
| 362 | test: /\.less$/i,
|
|---|
| 363 | use: [
|
|---|
| 364 | "style-loader",
|
|---|
| 365 | "css-loader",
|
|---|
| 366 | {
|
|---|
| 367 | loader: "less-loader",
|
|---|
| 368 | options: {
|
|---|
| 369 | implementation: require.resolve("less"),
|
|---|
| 370 | },
|
|---|
| 371 | },
|
|---|
| 372 | ],
|
|---|
| 373 | },
|
|---|
| 374 | ],
|
|---|
| 375 | },
|
|---|
| 376 | };
|
|---|
| 377 | ```
|
|---|
| 378 |
|
|---|
| 379 | ## Examples
|
|---|
| 380 |
|
|---|
| 381 | ### Normal usage
|
|---|
| 382 |
|
|---|
| 383 | Chain the `less-loader` with the [`css-loader`](https://github.com/webpack-contrib/css-loader) and the [`style-loader`](https://github.com/webpack-contrib/style-loader) to immediately apply all styles to the DOM.
|
|---|
| 384 |
|
|---|
| 385 | **webpack.config.js**
|
|---|
| 386 |
|
|---|
| 387 | ```js
|
|---|
| 388 | module.exports = {
|
|---|
| 389 | module: {
|
|---|
| 390 | rules: [
|
|---|
| 391 | {
|
|---|
| 392 | test: /\.less$/i,
|
|---|
| 393 | use: [
|
|---|
| 394 | {
|
|---|
| 395 | loader: "style-loader", // creates style nodes from JS strings
|
|---|
| 396 | },
|
|---|
| 397 | {
|
|---|
| 398 | loader: "css-loader", // translates CSS into CommonJS
|
|---|
| 399 | },
|
|---|
| 400 | {
|
|---|
| 401 | loader: "less-loader", // compiles Less to CSS
|
|---|
| 402 | },
|
|---|
| 403 | ],
|
|---|
| 404 | },
|
|---|
| 405 | ],
|
|---|
| 406 | },
|
|---|
| 407 | };
|
|---|
| 408 | ```
|
|---|
| 409 |
|
|---|
| 410 | Unfortunately, Less doesn't map all options 1-by-1 to camelCase. When in doubt, [check their executable](https://github.com/less/less.js/blob/3.x/bin/lessc) and search for the dash-case option.
|
|---|
| 411 |
|
|---|
| 412 | ### Source maps
|
|---|
| 413 |
|
|---|
| 414 | To enable sourcemaps for CSS, you'll need to pass the `sourceMap` property in the loader's options. If this is not passed, the loader will respect the setting for webpack source maps, set in `devtool`.
|
|---|
| 415 |
|
|---|
| 416 | **webpack.config.js**
|
|---|
| 417 |
|
|---|
| 418 | ```js
|
|---|
| 419 | module.exports = {
|
|---|
| 420 | devtool: "source-map", // any "source-map"-like devtool is possible
|
|---|
| 421 | module: {
|
|---|
| 422 | rules: [
|
|---|
| 423 | {
|
|---|
| 424 | test: /\.less$/i,
|
|---|
| 425 | use: [
|
|---|
| 426 | "style-loader",
|
|---|
| 427 | {
|
|---|
| 428 | loader: "css-loader",
|
|---|
| 429 | options: {
|
|---|
| 430 | sourceMap: true,
|
|---|
| 431 | },
|
|---|
| 432 | },
|
|---|
| 433 | {
|
|---|
| 434 | loader: "less-loader",
|
|---|
| 435 | options: {
|
|---|
| 436 | sourceMap: true,
|
|---|
| 437 | },
|
|---|
| 438 | },
|
|---|
| 439 | ],
|
|---|
| 440 | },
|
|---|
| 441 | ],
|
|---|
| 442 | },
|
|---|
| 443 | };
|
|---|
| 444 | ```
|
|---|
| 445 |
|
|---|
| 446 | If you want to edit the original Less files inside Chrome, [there's a good blog post](https://medium.com/@toolmantim/getting-started-with-css-sourcemaps-and-in-browser-sass-editing-b4daab987fb0). The blog post is about Sass but it also works for Less.
|
|---|
| 447 |
|
|---|
| 448 | ### In production
|
|---|
| 449 |
|
|---|
| 450 | Usually, it's recommended to extract the style sheets into a dedicated file in production using the [MiniCssExtractPlugin](https://github.com/webpack-contrib/mini-css-extract-plugin). This way your styles are not dependent on JavaScript.
|
|---|
| 451 |
|
|---|
| 452 | ### Imports
|
|---|
| 453 |
|
|---|
| 454 | First we try to use built-in `less` resolve logic, then `webpack` resolve logic (aliases and `~`).
|
|---|
| 455 |
|
|---|
| 456 | #### Webpack Resolver
|
|---|
| 457 |
|
|---|
| 458 | `webpack` provides an [advanced mechanism to resolve files](https://webpack.js.org/configuration/resolve/).
|
|---|
| 459 | `less-loader` applies a Less plugin that passes all queries to the webpack resolver if `less` could not resolve `@import`.
|
|---|
| 460 | Thus you can import your Less modules from `node_modules`.
|
|---|
| 461 |
|
|---|
| 462 | ```css
|
|---|
| 463 | @import "bootstrap/less/bootstrap";
|
|---|
| 464 | ```
|
|---|
| 465 |
|
|---|
| 466 | Using `~` is deprecated and can be removed from your code (**we recommend it**), but we still support it for historical reasons.
|
|---|
| 467 | Why you can removed it? The loader will first try to resolve `@import` as relative, if it cannot be resolved, the loader will try to resolve `@import` inside [`node_modules`](https://webpack.js.org/configuration/resolve/#resolve-modules).
|
|---|
| 468 | Just prepend them with a `~` which tells webpack to look up the [`modules`](https://webpack.js.org/configuration/resolve/#resolve-modules).
|
|---|
| 469 |
|
|---|
| 470 | ```css
|
|---|
| 471 | @import "~bootstrap/less/bootstrap";
|
|---|
| 472 | ```
|
|---|
| 473 |
|
|---|
| 474 | Default resolver options can be modified by [`resolve.byDependency`](https://webpack.js.org/configuration/resolve/#resolvebydependency):
|
|---|
| 475 |
|
|---|
| 476 | **webpack.config.js**
|
|---|
| 477 |
|
|---|
| 478 | ```js
|
|---|
| 479 | module.exports = {
|
|---|
| 480 | devtool: "source-map", // any "source-map"-like devtool is possible
|
|---|
| 481 | module: {
|
|---|
| 482 | rules: [
|
|---|
| 483 | {
|
|---|
| 484 | test: /\.less$/i,
|
|---|
| 485 | use: ["style-loader", "css-loader", "less-loader"],
|
|---|
| 486 | },
|
|---|
| 487 | ],
|
|---|
| 488 | },
|
|---|
| 489 | resolve: {
|
|---|
| 490 | byDependency: {
|
|---|
| 491 | // More options can be found here https://webpack.js.org/configuration/resolve/
|
|---|
| 492 | less: {
|
|---|
| 493 | mainFiles: ["custom"],
|
|---|
| 494 | },
|
|---|
| 495 | },
|
|---|
| 496 | },
|
|---|
| 497 | };
|
|---|
| 498 | ```
|
|---|
| 499 |
|
|---|
| 500 | It's important to only prepend it with `~`, because `~/` resolves to the home-directory. webpack needs to distinguish between `bootstrap` and `~bootstrap`, because CSS and Less files have no special syntax for importing relative files. Writing `@import "file"` is the same as `@import "./file";`
|
|---|
| 501 |
|
|---|
| 502 | #### Less Resolver
|
|---|
| 503 |
|
|---|
| 504 | If you specify the `paths` option, modules will be searched in the given `paths`. This is `less` default behavior. `paths` should be an array with absolute paths:
|
|---|
| 505 |
|
|---|
| 506 | **webpack.config.js**
|
|---|
| 507 |
|
|---|
| 508 | ```js
|
|---|
| 509 | module.exports = {
|
|---|
| 510 | module: {
|
|---|
| 511 | rules: [
|
|---|
| 512 | {
|
|---|
| 513 | test: /\.less$/i,
|
|---|
| 514 | use: [
|
|---|
| 515 | {
|
|---|
| 516 | loader: "style-loader",
|
|---|
| 517 | },
|
|---|
| 518 | {
|
|---|
| 519 | loader: "css-loader",
|
|---|
| 520 | },
|
|---|
| 521 | {
|
|---|
| 522 | loader: "less-loader",
|
|---|
| 523 | options: {
|
|---|
| 524 | lessOptions: {
|
|---|
| 525 | paths: [path.resolve(__dirname, "node_modules")],
|
|---|
| 526 | },
|
|---|
| 527 | },
|
|---|
| 528 | },
|
|---|
| 529 | ],
|
|---|
| 530 | },
|
|---|
| 531 | ],
|
|---|
| 532 | },
|
|---|
| 533 | };
|
|---|
| 534 | ```
|
|---|
| 535 |
|
|---|
| 536 | ### Plugins
|
|---|
| 537 |
|
|---|
| 538 | In order to use [plugins](http://lesscss.org/usage/#plugins), simply set the `plugins` option like this:
|
|---|
| 539 |
|
|---|
| 540 | **webpack.config.js**
|
|---|
| 541 |
|
|---|
| 542 | ```js
|
|---|
| 543 | const CleanCSSPlugin = require('less-plugin-clean-css');
|
|---|
| 544 |
|
|---|
| 545 | module.exports = {
|
|---|
| 546 | ...
|
|---|
| 547 | {
|
|---|
| 548 | loader: 'less-loader',
|
|---|
| 549 | options: {
|
|---|
| 550 | lessOptions: {
|
|---|
| 551 | plugins: [
|
|---|
| 552 | new CleanCSSPlugin({ advanced: true }),
|
|---|
| 553 | ],
|
|---|
| 554 | },
|
|---|
| 555 | },
|
|---|
| 556 | },
|
|---|
| 557 | ...
|
|---|
| 558 | };
|
|---|
| 559 | ```
|
|---|
| 560 |
|
|---|
| 561 | > ℹ️ Access to the [loader context](https://webpack.js.org/api/loaders/#the-loader-context) inside the custom plugin can be done using the `pluginManager.webpackLoaderContext` property.
|
|---|
| 562 |
|
|---|
| 563 | ```js
|
|---|
| 564 | module.exports = {
|
|---|
| 565 | install: function (less, pluginManager, functions) {
|
|---|
| 566 | functions.add("pi", function () {
|
|---|
| 567 | // Loader context is available in `pluginManager.webpackLoaderContext`
|
|---|
| 568 |
|
|---|
| 569 | return Math.PI;
|
|---|
| 570 | });
|
|---|
| 571 | },
|
|---|
| 572 | };
|
|---|
| 573 | ```
|
|---|
| 574 |
|
|---|
| 575 | ### Extracting style sheets
|
|---|
| 576 |
|
|---|
| 577 | Bundling CSS with webpack has some nice advantages like referencing images and fonts with hashed urls or [hot module replacement](https://webpack.js.org/concepts/hot-module-replacement/) in development. In production, on the other hand, it's not a good idea to apply your style sheets depending on JS execution. Rendering may be delayed or even a [FOUC](https://en.wikipedia.org/wiki/Flash_of_unstyled_content) might be visible. Thus it's often still better to have them as separate files in your final production build.
|
|---|
| 578 |
|
|---|
| 579 | There are two possibilities to extract a style sheet from the bundle:
|
|---|
| 580 |
|
|---|
| 581 | - [`extract-loader`](https://github.com/peerigon/extract-loader) (simpler, but specialized on the css-loader's output)
|
|---|
| 582 | - [MiniCssExtractPlugin](https://github.com/webpack-contrib/mini-css-extract-plugin) (more complex, but works in all use-cases)
|
|---|
| 583 |
|
|---|
| 584 | ### CSS modules gotcha
|
|---|
| 585 |
|
|---|
| 586 | There is a known problem with Less and [CSS modules](https://github.com/css-modules/css-modules) regarding relative file paths in `url(...)` statements. [See this issue for an explanation](https://github.com/webpack-contrib/less-loader/issues/109#issuecomment-253797335).
|
|---|
| 587 |
|
|---|
| 588 | ## Contributing
|
|---|
| 589 |
|
|---|
| 590 | Please take a moment to read our contributing guidelines if you haven't yet done so.
|
|---|
| 591 |
|
|---|
| 592 | [CONTRIBUTING](./.github/CONTRIBUTING.md)
|
|---|
| 593 |
|
|---|
| 594 | ## License
|
|---|
| 595 |
|
|---|
| 596 | [MIT](./LICENSE)
|
|---|
| 597 |
|
|---|
| 598 | [npm]: https://img.shields.io/npm/v/less-loader.svg
|
|---|
| 599 | [npm-url]: https://npmjs.com/package/less-loader
|
|---|
| 600 | [node]: https://img.shields.io/node/v/less-loader.svg
|
|---|
| 601 | [node-url]: https://nodejs.org
|
|---|
| 602 | [deps]: https://david-dm.org/webpack-contrib/less-loader.svg
|
|---|
| 603 | [deps-url]: https://david-dm.org/webpack-contrib/less-loader
|
|---|
| 604 | [tests]: https://github.com/webpack-contrib/less-loader/workflows/less-loader/badge.svg
|
|---|
| 605 | [tests-url]: https://github.com/webpack-contrib/less-loader/actions
|
|---|
| 606 | [cover]: https://codecov.io/gh/webpack-contrib/less-loader/branch/master/graph/badge.svg
|
|---|
| 607 | [cover-url]: https://codecov.io/gh/webpack-contrib/less-loader
|
|---|
| 608 | [chat]: https://img.shields.io/badge/gitter-webpack%2Fwebpack-brightgreen.svg
|
|---|
| 609 | [chat-url]: https://gitter.im/webpack/webpack
|
|---|
| 610 | [size]: https://packagephobia.now.sh/badge?p=less-loader
|
|---|
| 611 | [size-url]: https://packagephobia.now.sh/result?p=less-loader
|
|---|
