vue-引入less和配置less变量到全局

一.安装less

npm i less less-loader --save-dev

二.设置less变量到全局

// 1.安装sass-resources-loader
npm install sass-resources-loader --save-dev

// 2.配置build/utils.js，找到exports.cssLoaders函数，如下
exports.cssLoaders = function (options) {
options = options || {}

const cssLoader = {
loader: 'css-loader',
options: {
sourceMap: options.sourceMap
}
}

const postcssLoader = {
loader: 'postcss-loader',
options: {
sourceMap: options.sourceMap
}
}

// 此处添加配置

// generate loader string to be used with extract text plugin
function generateLoaders (loader, loaderOptions) {
const loaders = options.usePostCSS ? [cssLoader, postcssLoader] : [cssLoader]

if (loader) {
loaders.push({
loader: loader + '-loader',
options: Object.assign({}, loaderOptions, {
sourceMap: options.sourceMap
})
})
}

// Extract CSS when that option is specified
// (which is the case during production build)
if (options.extract) {
return ExtractTextPlugin.extract({
use: loaders,
fallback: 'vue-style-loader'
})
} else {
return ['vue-style-loader'].concat(loaders)
}
}

// https://vue-loader.vuejs.org/en/configurations/extract-css.html
return {
css: generateLoaders(),
postcss: generateLoaders(),
less: generateLoaders('less'), // 第二步更改这里
sass: generateLoaders('sass', { indentedSyntax: true }),
scss: generateLoaders('sass'),
stylus: generateLoaders('stylus'),
styl: generateLoaders('stylus')
}
}

在上面注释“// 此处添加配置”处添加如下代码：

// 配置less变量全局
function lessResourceLoader() {
var loaders = [
cssLoader,
'less-loader',
{
loader: 'sass-resources-loader',
options: {
resources: [
path.resolve(__dirname, '../src/assets/style/var.less'), // ../src/assets/style/var.less为你的全局less变量的文件目录
]
}
}
]
if (options.extract) {
return ExtractTextPlugin.extract({
use: loaders,
fallback: 'vue-style-loader'
})
} else {
return ['vue-style-loader'].concat(loaders)
}
}

3.更改exports.cssLoaders函数的return参数，将less: generateLoaders(‘less’)改为 less: lessResourceLoader(‘less’)，如下：

return {
css: generateLoaders(),
postcss: generateLoaders(),
//  less: generateLoaders('less'), // 更改这里为下面一行
less: lessResourceLoader('less'),  // lessResourceLoader即第一步添加的函数名
sass: generateLoaders('sass', { indentedSyntax: true }),
scss: generateLoaders('sass'),
stylus: generateLoaders('stylus'),
styl: generateLoaders('stylus')
}

经过上面两处更改后，exports.cssLoaders函数如下：

exports.cssLoaders = function (options) {
options = options || {}

const cssLoader = {
loader: 'css-loader',
options: {
sourceMap: options.sourceMap
}
}

const postcssLoader = {
loader: 'postcss-loader',
options: {
sourceMap: options.sourceMap
}
}

// 第一步：配置less变量全局
function lessResourceLoader() {
var loaders = [
cssLoader,
'less-loader',
{
loader: 'sass-resources-loader',
options: {
resources: [
path.resolve(__dirname, '../src/assets/style/var.less'), // ../src/assets/style/var.less为你的全局less变量的文件目录
]
}
}
]
if (options.extract) {
return ExtractTextPlugin.extract({
use: loaders,
fallback: 'vue-style-loader'
})
} else {
return ['vue-style-loader'].concat(loaders)
}
}

// generate loader string to be used with extract text plugin
function generateLoaders (loader, loaderOptions) {
const loaders = options.usePostCSS ? [cssLoader, postcssLoader] : [cssLoader]

if (loader) {
loaders.push({
loader: loader + '-loader',
options: Object.assign({}, loaderOptions, {
sourceMap: options.sourceMap
})
})
}

// Extract CSS when that option is specified
// (which is the case during production build)
if (options.extract) {
return ExtractTextPlugin.extract({
use: loaders,
fallback: 'vue-style-loader'
})
} else {
return ['vue-style-loader'].concat(loaders)
}
}

// https://vue-loader.vuejs.org/en/configurations/extract-css.html
return {
css: generateLoaders(),
postcss: generateLoaders(),
// 第二步： less: generateLoaders('less')更改为 less: lessResourceLoader('')
// less: generateLoaders('less'),
less: lessResourceLoader(''),
sass: generateLoaders('sass', { indentedSyntax: true }),
scss: generateLoaders('sass'),
stylus: generateLoaders('stylus'),
styl: generateLoaders('stylus')
}
}

重启项目即可