用户定义 | custom-ident (Lists & Counters) - CSS 中文开发手册 - Break易站


  • ??CSS 中文开发手册

    用户定义 | custom-ident (Lists & Counters) - CSS 中文开发手册

    <custom-ident>CSS数据类型表示作为任意用户定义的字符串的标识符。它是区分大小写的,并且在各种情况下禁止某些值以防止含糊不清。

    句法

    其语法<custom-ident>与CSS标识符(如属性名称)类似,区别在于区分大小写。A <custom-ident>是一个字符序列,字符可以是:

    任何字母字符‘A‘到‘Z‘,或‘a‘到‘z‘,任何十进制数字‘0‘到‘9‘,连字符‘-‘,下划线‘_‘,一个带有反斜杠的转义字符‘\‘,或一个Unicode字符(格式为反斜杠,后面跟着一到六个十六进制数字,表示其Unicode码位)。

    第一个字符不能是十进制数字,也不能是破折号(‘-‘),后面跟十进制数字或其他短划线。甲<custom-ident>不能放置单引号或双引号之间,因为这将是相同的<string>。

    需要注意的是id1,Id1,iD1和ID1都是不同的标识符,因为它们区分大小写。另一方面,由于有几种逃避角色的方法,toto\?并且toto\3F是相同的标识符。

    禁忌值

    为了防止歧义,每个属性使用<custom-ident>禁止使用特定值:

    animation-name全局禁止CSS值(unset,,initial和inherit),以及none。counter-resetcounter-increment禁止全球CSS值(unset,,initial和inherit),以及none。@counter-stylelist-style-type禁止全局CSS值(unset,initial,和inherit),以及价值观none,inline和outside。此外,相当多的预设值是由不同的浏览器中实现:disc,circle,square,decimal,cjk-decimal,decimal-leading-zero,lower-roman,upper-roman,lower-greek,lower-alpha,lower-latin,upper-alpha,upper-latin,arabic-indic,armenian,bengali,cambodian,cjk-earthly-branch,cjk-heavenly-stem,cjk-ideographic,devanagari,ethiopic-numeric,georgian,gujarati,gurmukhi,hebrew,hiragana,hiragana-iroha,japanese-formal,japanese-informal,kannada,katakana,katakana-iroha,khmer,korean-hangul-formal,korean-hanja-formal,korean-hanja-informal,lao,lower-armenian,malayalam,*n,myanmar,oriya,persian,simp-chinese-formal,simp-chinese-informal,tamil,telugu,thai,*,trad-chinese-formal,trad-chinese-informal,upper-armenian,disclosure-open,和disclosure-close。grid-row-start

    grid-row-end

    grid-column-start

    grid-column-end禁止span价值。will-change禁止全局CSS值(unset,initial,和inherit),以及价值观will-change,auto,scroll-position,和contents。

    实例

    有效标识符

    nono79            A mix of alphanumeric characters and numbers
    ground-level      A mix of alphanumeric characters and a dash
    -test             A dash followed by alphanumeric characters
    _internal         An underscore followed by alphanumeric characters
     toto          A Unicode character followed by a sequence of alphanumeric characters
    bili\.bob         A correctly escaped period

    无效标识符

    34rem             It must not start with a decimal digit.
    -12rad            It must not start with a dash followed by a decimal digit.
    bili.bob          Only alphanumeric characters, _, and - needn‘t be escaped.
    --toto            It must not start with two dashes. This would be a custom property.
    ‘bilibob‘         This would be a <string>.
    "bilibob"         This would be a <string>.

    规格

    Specification

    Status

    Comment

    CSS Will Change Module Level 1The definition of ‘<custom-ident> for will-change‘ in that specification.

    Working Draft

    Defines which values are excluded for will-change.

    CSS Counter Styles Level 3The definition of ‘<custom-ident> for list-style-type‘ in that specification.

    Candidate Recommendation

    Uses <custom-ident> instead of a finite list of keywords. Defines which values are excluded for list-style-type and @counter-style.

    CSS Lists and Counters Module Level 3The definition of ‘<custom-ident> for counter-*‘ in that specification.

    Working Draft

    Renames <identifier> to <custom-ident>. Adds its usage to the new counter-set property.

    CSS AnimationsThe definition of ‘<custom-ident> for animation-name‘ in that specification.

    Working Draft

    Defines which values are excluded for animation-name.

    CSS Values and Units Module Level 3The definition of ‘<custom-ident>‘ in that specification.

    Candidate Recommendation

    Renames <identifier> to <custom-ident>. Makes it a pseudo-type and forbids the use of excluded values.

    CSS Level 2 (Revision 1)The definition of ‘<identifier>‘ in that specification.

    Recommendation

    Initial definition.

    浏览器兼容性

    
    
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