#function-url-scheme-whitelist

Specify a whitelist of allowed url schemes.

指定一个允许的 url 协议的白名单。

a { background-image: url('http://www.example.com/file.jpg'); }
/**                        ↑
 *           This url scheme */

A url scheme consists of alphanumeric, +, -, and . characters. It can appear at the start of a url and is followed by :.

一个url 协议由字母，+，- 和 . 字符组成。它出现在一个链接的的开始位置，后面紧随着 :。

This rule treats url schemes as case insensitive (https and HTTPS are the same).

该规则对 url 协议不区分大小写 (https 和 HTTPS 是一样的)。

This rule ignores url arguments without an existing url scheme.

该规则忽略不带 url 协议的 url 参数。

This rule ignores url arguments with variables or variable interpolation ($sass, @less, --custom-property, #{$var}, @{var}, $(var)).

该规则忽略带有变量或变量插值 ($sass，@less，--custom-property，#{$var}，@{var}，$(var))的 url 参数。

#Options

array|string: ["array", "of", "schemes"]|"scheme"

Given:

给出：

["https", "data"]

The following patterns are considered warnings:

以下模式被认为是个警告：

a { background-image: url('http://www.example.com/file.jpg'); }

a { background-image: url('ftp://www.example.com/file.jpg'); }

The following patterns are not considered warnings:

以下模式正常：

a { background-image: url('https://www.example.com/file.jpg'); }

a { background-image: url('HTTPS://www.example.com/file.jpg'); }

a { background-image: url('data:image/gif;base64,R0lGODlhAQABAIAAAAUEBAAAACwAAAAAAQABAAACAkQBADs='); }

a { background-image: url('example.com/file.jpg'); }

a { background-image: url('/example.com/file.jpg'); }

a { background-image: url('//example.com/file.jpg'); }

a { background-image: url('./path/to/file.jpg'); }