CSS标识符的允许字符 [英] Allowed characters for CSS identifiers

问题描述

CSS标识符 id 和类 $ c>？

有没有正规表达式可以用来验证？是不是浏览器不可知？

解决方案

字符集无所谓。允许的字符更重要。请检查 CSS规范。以下是相关的引用： 在bss中，标识符（包括 selectors ）只能包含字符 [a-zA-Z0-9] code>和ISO 10646字符 U + 00A1 和更高，加上连字符（ - ）和下划线（ _ ）;他们不能以数字开头，或者连字符后跟数字。标识符还可以包含转义字符和任何ISO 10646字符作为数字代码（见下一项）。例如，标识符B& W？可以写为B \& W \？或B \26 W \3F。

更新：对于正则表达式问题，您可以找到语法此处：

  ident  - ？{nmstart} {nmchar} * 
  

其中包含以下部分：

  nmstart [_a-z] | {nonascii} | {escape} 
 nmchar [_a-z0-9-] | {nonascii} | {escape} 
 nonascii [\240-\377] 
 escape {unicode} | \\ [^ \r\\\
\f0-9a-f] 
 unicode \\ {h} {1,6}（\r \\\
 | [\t\r\\\
\f]）？ 
h [0-9a-f] 
  

这可以转换为Java正则表达式如下（我只添加括号到包含OR的部分并转义反斜杠）：

  String h =[0-9a-f ]; 
 String unicode =\\\\ {h} {1,6}（\\r\\\\
 | [\\t\\r\\\ \\ n\\f]）？。replace（{h}，h）; 
 String escape =（{unicode} | \\\\ [^ \\r\\\\
\\f0-9a-f]）replace（{ unicode}，unicode）; 
 String nonascii =[\\240 -\\377]; 
 String nmchar =（[_a-z0-9-] | {nonascii} | {escape}）replace（{nonascii}，nonascii）.replace（{escape}，escape）; 
 String nmstart =（[_a-z] | {nonascii} | {escape}）replace（{nonascii}，nonascii）.replace（{escape}，escape）; 
 String ident = - ？{nmstart} {nmchar} *。replace（{nmstart}，nmstart）.replace（{nmchar}，nmchar）; 
 
 System.out.println（ident）; //完整的正则表达式。 
  

更新2 ：哦，好吧，我想你可以怎么/在哪里做 str_replace ？

What are the (full) valid / allowed charset characters for CSS identifiers id and class?

Is there a regular expression that I can use to validate against? Is it browser agnostic?

解决方案

The charset doesn't matter. The allowed characters matters more. Check the CSS specification. Here's a cite of relevance:

In CSS, identifiers (including element names, classes, and IDs in selectors) can contain only the characters [a-zA-Z0-9] and ISO 10646 characters U+00A1 and higher, plus the hyphen (-) and the underscore (_); they cannot start with a digit, or a hyphen followed by a digit. Identifiers can also contain escaped characters and any ISO 10646 character as a numeric code (see next item). For instance, the identifier "B&W?" may be written as "B\&W\?" or "B\26 W\3F".

Update: As to the regex question, you can find the grammar here:

ident      -?{nmstart}{nmchar}*

Which contains of the parts:

nmstart    [_a-z]|{nonascii}|{escape}
nmchar     [_a-z0-9-]|{nonascii}|{escape}
nonascii   [\240-\377]
escape     {unicode}|\\[^\r\n\f0-9a-f]
unicode    \\{h}{1,6}(\r\n|[ \t\r\n\f])?
h          [0-9a-f]

This can be translated to a Java regex as follows (I only added parentheses to parts containing the OR and escaped the backslashes):

String h = "[0-9a-f]";
String unicode = "\\\\{h}{1,6}(\\r\\n|[ \\t\\r\\n\\f])?".replace("{h}", h);
String escape = "({unicode}|\\\\[^\\r\\n\\f0-9a-f])".replace("{unicode}", unicode);
String nonascii = "[\\240-\\377]";
String nmchar = "([_a-z0-9-]|{nonascii}|{escape})".replace("{nonascii}", nonascii).replace("{escape}", escape);
String nmstart = "([_a-z]|{nonascii}|{escape})".replace("{nonascii}", nonascii).replace("{escape}", escape);
String ident = "-?{nmstart}{nmchar}*".replace("{nmstart}", nmstart).replace("{nmchar}", nmchar);

System.out.println(ident); // The full regex.

Update 2: oh, you're more a PHP'er, well I think you can figure how/where to do str_replace?

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