SASS 学习-CFANZ编程社区

简介

sass是css3的扩展，增加了嵌套、变量、混合、选择器继承等。
它使用scss语法。

安装

安装Ruby

windows下载：
http://rubyinstaller.org/

安装sass

国内先更换gem安装源

gem sources --add https://ruby.taobao.org/ --remove https://rubygems.org/

命令行输入：

gem install sass
gem install compass

SASS 学习_扩展

使用命令

sass 转换为 scss

sass-convert style.sass style.scss

scss 转换为sass

sass-convert style.scss style.sass

sass 输出css

sass input.scss output.css

监控自动编译

sass –watch input.scss:output.css

SCSS语法

变量

$font-stack:    Helvetica, sans-serif;
$primary-color: #333;

body {
  font: 100% $font-stack;
  color: $primary-color;
}

编译后

body {
  font: 100% Helvetica, sans-serif;
  color: #333;
}

SASS语法

nested语法

示例：

nav {
  ul {
    margin: 0;
    padding: 0;
    list-style: none;
  }

  li { display: inline-block; }

  a {
    display: block;
    padding: 6px 12px;
    text-decoration: none;
  }
}

编译后：

nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

nav li {
  display: inline-block;
}

nav a {
  display: block;
  padding: 6px 12px;
  text-decoration: none;
}

引用

a {
  font-weight: bold;
  text-decoration: none;
  &:hover { text-decoration: underline; }
  body.firefox & { font-weight: normal; }
}

编译后：

a {
  font-weight: bold;
  text-decoration: none; }
  a:hover {
    text-decoration: underline; }
  body.firefox a {
    font-weight: normal; }

Nested属性

.funky {
  font: {
    family: fantasy;
    size: 30em;
    weight: bold;
  }
}

编译后：

.funky {
  font-family: fantasy;
  font-size: 30em;
  font-weight: bold; }

缩进

#sidebar
  width: 30%
  background-color: #faa

编译成css会是：

#sidebar {
  width: 30%;
  background-color: #faa;
}

注释：

/* This comment is
 * several lines long.
 * since it uses the CSS comment syntax,
 * it will appear in the CSS output. */
body { color: black; }

// These comments are only one line long each.
// They won't appear in the CSS output,
// since they use the single-line comment syntax.
a { color: green; }

包含

子scss文件格式：_partial.scss

@import ‘reset’;

Mixins

@mixin border-radius($radius) {
  -webkit-border-radius: $radius;
     -moz-border-radius: $radius;
      -ms-border-radius: $radius;
          border-radius: $radius;
}

.box { @include border-radius(10px); }

编译后：

.box {
  -webkit-border-radius: 10px;
  -moz-border-radius: 10px;
  -ms-border-radius: 10px;
  border-radius: 10px;
}

继承

.message {
  border: 1px solid #ccc;
  padding: 10px;
  color: #333;
}

.success {
  @extend .message;
  border-color: green;
}

.error {
  @extend .message;
  border-color: red;
}

.warning {
  @extend .message;
  border-color: yellow;
}

编译后：

.message, .success, .error, .warning {
  border: 1px solid #cccccc;
  padding: 10px;
  color: #333;
}

.success {
  border-color: green;
}

.error {
  border-color: red;
}

.warning {
  border-color: yellow;
}

运算

.container { width: 100%; }

article[role="main"] {
  float: left;
  width: 600px / 960px * 100%;
}

aside[role="complimentary"] {
  float: right;
  width: 300px / 960px * 100%;
}

编译后：

.container {
  width: 100%;
}

article[role="main"] {
  float: left;
  width: 62.5%;
}

aside[role="complimentary"] {
  float: right;
  width: 31.25%;
}

SassScript

控制台测试

$ sass -i
>> "Hello, Sassy World!"
"Hello, Sassy World!"
>> 1px + 1px + 1px
3px
>> #777 + #777
#eeeeee
>> #777 + #888
white

SASS 学习_gem_02

变量

$width: 5em;
#main {
  width: $width;
}

变量有作用域限制，默认是在自己的nested生效。如果要全局生效，使用

$width: 5em ~global;

数据类型

numbers (e.g. 1.2, 13, 10px)
strings of text, with and without quotes (e.g. “foo”, ‘bar’, baz)
colors (e.g. blue, #04a3f9, rgba(255, 0, 0, 0.5))
booleans (e.g. true, false)
nulls (e.g. null)
lists of values, separated by spaces or commas (e.g. 1.5em 1em 0 2em, Helvetica, Arial, sans-serif)
maps from one value to another (e.g. (key1: value1, key2: value2))

字符串

列表

map键值对

参考文章：
http://sass-lang.com/guide