less官方介绍文档（http://lesscss.org/#docs）

Getting Started

Less is a CSS pre-processor, meaning that it extends the CSS language, adding features that allow variables, mixins, functions and many other techniques that allow you to make CSS that is more maintainable, themeable and extendable.

Less runs inside Node, in the browser and inside Rhino. There are also many 3rd party tools that allow you to compile your files and watch for changes. The quickest place for first experiments with less is our online editor.

For example:

@base: #f938ab;

.box-shadow(@style, @c) when (iscolor(@c)) {

  -webkit-box-shadow: @style @c;

  box-shadow:         @style @c;

}

.box-shadow(@style, @alpha: 50%) when (isnumber(@alpha)) {

  .box-shadow(@style, rgba(0, 0, 0, @alpha));

}

.box {

  color: saturate(@base, 5%);

  border-color: lighten(@base, 30%);

  div { .box-shadow(0 0 5px, 30%) }

}

compiles to

.box {

  color: #fe33ac;

  border-color: #fdcdea;

}

.box div {

  -webkit-box-shadow: 0 0 5px rgba(0, 0, 0, 0.3);

  box-shadow: 0 0 5px rgba(0, 0, 0, 0.3);

}

Using Less

Less can be used on the command line via npm, downloaded as a script file for the browser or used in a wide variety of third party tools. See the Usage section for more detailed information.

Installation

The easiest way to install Less on the server, is via npm, the node.js package manager, as so:

$ npm install -g less

Command-line Usage

Once installed, you can invoke the compiler from the command-line, as such:

$ lessc styles.less

This will output the compiled CSS to stdout. To save the CSS result to a file of your choice use:

$ lessc styles.less styles.css

To output minified CSS you can use the clean-css plugin. When the plugin is installed, a minified CSS output is specified with --clean-css option:

$ lessc --clean-css styles.less styles.min.css

To see all the command line options run lessc without parameters or see Usage.

Usage in Code

You can invoke the compiler from node, as such:

var less = require('less');

less.render('.class { width: (1 + 1) }', function (e, output) {

  console.log(output.css);

});

which will output

.class {

  width: 2;

}

Configuration

You may pass some options to the compiler:

var less = require('less');

less.render('.class { width: (1 + 1) }',

    {

      paths: ['.', './lib'],  // Specify search paths for @import directives

      filename: 'style.less', // Specify a filename, for better error messages

      compress: true          // Minify CSS output

    },

    function (e, output) {

       console.log(output.css);

    });

See Usage for more information.

Third Party Tools

See the Usage section for details of other tools.

Client-side Usage

Using less.js in the browser is great for development, but it's not recommended for production

Client-side is the easiest way to get started and good for developing with Less, but in production, when performance and reliability is important, we recommend pre-compiling using node.js or one of the many third party tools available.

To start off, link your .less stylesheets with the rel attribute set to "stylesheet/less":

<link rel="stylesheet/less" type="text/css" href="styles.less" />

Next, download less.js and include it in a <script></script> tag in the <head> element of your page:

<script src="less.js" type="text/javascript"></script>

Tips

  • Make sure you include your stylesheets before the script.
  • When you link more than one .less stylesheet each of them is compiled independently. So any variables, mixins or namespaces you define in a stylesheet are not accessible in any other.
  • Due to the same origin policy of browsers loading external resources requires enabling CORS

Browser Options

Options are defined by setting them on a global less object before the <script src="less.js"></script>:

<!-- set options before less.js script -->

<script>

  less = {

    env: "development",

    async: false,

    fileAsync: false,

    poll: 1000,

    functions: {},

    dumpLineNumbers: "comments",

    relativeUrls: false,

    rootpath: ":/a.com/"

  };

</script>

<script src="less.js"></script>

Or for brevity they can be set as attributes on the script and link tags (requires JSON.parse browser support or polyfill).

<script src="less.js" data-poll="1000" data-relative-urls="false"></script>

<link data-dump-line-numbers="all" data-global-vars='{ myvar: "#ddffee", mystr: "\"quoted\"" }' rel="stylesheet/less" type="text/css" href="less/styles.less">

Learn more about Browser Options

Get Less.js

Browser downloads

Download Less.js v2.7.2

Download Source Code

Get the latest Less.js source code by downloading it directly from GitHub.

Clone or Fork via GitHub

Fork the project and send us a pull request!

Install with Bower

Install the Less.js project and JavaScript by running the following in the command line:

bower install less

Less CDN

<script src="//cdnjs.cloudflare.com/ajax/libs/less.js/2.7.2/less.min.js"></script>

License FAQs

Less.js is released under the Apache 2 License (though there are plans to dual license it). Copyright 2009-2017, Alexis Sellier and the Less Core Team (see about). Boiled down to smaller chunks, it can be described with the following conditions.

It allows you to:

  • Freely download and use Less.js, in whole or in part, for personal, company internal or commercial purposes
  • Use Less.js in packages or distributions that you create

It forbids you to:

  • Redistribute any piece of Less.js without proper attribution

It requires you to:

  • Include a copy of the license in any redistribution you may make that includes Less.js
  • Provide clear attribution to The Less Core Team for any distributions that include Less.js

It does not require you to:

  • Include the source of Less.js itself, or of any modifications you may have made to it, in any redistribution you may assemble that includes it
  • Submit changes that you make to Less.js back to the Less.js project (though such feedback is encouraged)

The full Less.js license is located in the project repository for more information.

LESS文档的更多相关文章

  1. C#给PDF文档添加文本和图片页眉

    页眉常用于显示文档的附加信息,我们可以在页眉中插入文本或者图形,例如,页码.日期.公司徽标.文档标题.文件名或作者名等等.那么我们如何以编程的方式添加页眉呢?今天,这篇文章向大家分享如何使用了免费组件 ...

  2. dotNET跨平台相关文档整理

    一直在从事C#开发的相关技术工作,从C# 1.0一路用到现在的C# 6.0, 通常情况下被局限于Windows平台,Mono项目把我们C#程序带到了Windows之外的平台,在工作之余花了很多时间在M ...

  3. ABP文档 - Javascript Api - AJAX

    本节内容: AJAX操作相关问题 ABP的方式 AJAX 返回信息 处理错误 HTTP 状态码 WrapResult和DontWrapResult特性 Asp.net Mvc 控制器 Asp.net ...

  4. ABP文档 - EntityFramework 集成

    文档目录 本节内容: Nuget 包 DbContext 仓储 默认仓储 自定义仓储 特定的仓储基类 自定义仓储示例 仓储最佳实践 ABP可使用任何ORM框架,它已经内置了EntityFrame(以下 ...

  5. ABP文档 - SignalR 集成

    文档目录 本节内容: 简介 安装 服务端 客户端 连接确立 内置功能 通知 在线客户端 帕斯卡 vs 骆峰式 你的SignalR代码 简介 使用Abp.Web.SignalR nuget包,使基于应用 ...

  6. ABP文档 - 通知系统

    文档目录 本节内容: 简介 发送模式 通知类型 通知数据 通知重要性 关于通知持久化 订阅通知 发布通知 用户通知管理器 实时通知 客户端 通知存储 通知定义 简介 通知用来告知用户系统里特定的事件发 ...

  7. ABP文档 - Hangfire 集成

    文档目录 本节内容: 简介 集成 Hangfire 面板授权 简介 Hangfire是一个综合的后台作业管理器,可以在ABP里集成它替代默认的后台作业管理器,你可以为Hangfire使用相同的后台作业 ...

  8. ABP文档 - 后台作业和工作者

    文档目录 本节内容: 简介 后台作业 关于作业持久化 创建一个后台作业 在队列里添加一个新作业 默认的后台作业管理器 后台作业存储 配置 禁用作业执行 Hangfire 集成 后台工作者 创建一个后台 ...

  9. ABP文档 - Javascript Api

    文档目录 本节内容: AJAX Notification Message UI Block & Busy Event Bus Logging Other Utility Functions A ...

  10. ABP文档 - 导航

    文档目录 本节内容: 创建菜单 注册导航供应器 显示菜单 每个web应用都有一些菜单用来在页面/屏幕之间导航,ABP提供了一个通用的基础框架创建并显示菜单给用户. 创建菜单 一个应用可能由不同模块组成 ...

随机推荐

  1. 第一章：火狐浏览器 ： 环境配置： FireFox 版本38 + jdk 7 + selenium 2.53.6 + selenum-version 2.48.2

    配置一套完整的 selenium + Java + Firefox38  环境: 1. 火狐浏览器的版本 : 38 2. JDK 安装 1.7 版本的 3. 安装 Python 的版本是 2.7 4. ...

  2. Android自动问题——黑屏、死机等解决方法

    今天用了下Android Studio,出现了一些问题,现在将启动过程中遇到的问题和解决方案列出来,方便大家参考. 安装过程不多说,网上一搜一大把. 那直接说问题吧: 1. 无法启动,报错:Faile ...

  3. Linux编译安装程序(使用configure、make、 make install)

    以安装vim为例. (vim 是vi的升级版本,它不仅兼容vi的所有指令,而且还有一些新的特性在里面). 1.获取源文件 首先进入/usr/local下(只是为了方便处理安装文件,位置随意) 用git ...

  4. selenium3.x 踏坑记

    Selenium 3.x 出来也有段时间了,有哪些坑呢? 有好长一段时间没有用selenium了.最近想用来做个web自动化的小工具.根据以往经验,firefox是不需要下载driver的.启动fir ...

  5. ubuntu的/etc/modules内核模块文件

    /etc/modules: 内核模块文件,里面列出的模块会在系统启动时自动加载. /etc/modprobe.d: 存放禁止加载或者加载内核模块脚本的目录. 以下是我增加netfilter模块是的流程 ...

  6. FaceRank-项目上了 GitHub Python Trending

    FaceRank-人脸打分基于 TensorFlow 的 CNN 模型 GitHub Python Trending 第一次上 trending ,虽然只是分类榜. https://github.co ...

  7. IDEA 2017注册码破解方法（转）

    进入ide主页面,help-register-license server,然后输入 http://idea.iteblog.com/key.PHP(注意:php要小写)即可~ 如下图: 点击 Act ...

  8. java笔录---反射机制(1)

    引言   为了方便记忆java的反射机制,在这里仔细的总结了一下.主要是怕以后忘记了,这样也方便回忆.因为最近利用空余时间深入的了解spring和Mybatis框架,   像spring中核心模块IO ...

  9. [补档][Usaco2015 Jan]Grass Cownoisseur

    [Usaco2015 Jan]Grass Cownoisseur 题目 给一个有向图,然后选一条路径起点终点都为1的路径出来,有一次机会可以沿某条边逆方向走,问最多有多少个点可以被经过? (一个点在路 ...

  10. JavaScript表单

    JavaScript表单 这篇文章的主要目的是介绍表单相关的知识,如表单基础知识.文本框脚本相关用法.选择框脚本相关用法以及等知识.虽然在现代web开发中,很少会使用form默认行为提交表单数据,而是 ...