Re: [CSS21] ambiguity parsing 'list-style'

L. David Baron wrote:
> http://www.w3.org/TR/CSS21/generate.html#propdef-list-style defines
> the syntax of the 'list-style' shorthand property to be:
> #       [ <'list-style-type'> || <'list-style-position'> ||
> #       <'list-style-image'> ] | inherit
> Since two of the three properties accept the value 'none', this
> definition is ambiguous.  For example, it's not clear whether the
> shorthand declaration:
>   list-style: outside none;
> should be expanded into:
>   list-style-position: outside;
>   list-style-type: none;
>   /* implicit list-style-image: none, the initial value */
> or:
>   list-style-position: outside;
>   list-style-image: none;
>   /* implicit list-style-type: disc, the initial value */
> 
> The spec tries to clarify this with the sentence:
>   # A value of 'none' for the 'list-style' property sets both
>   # 'list-style-type' and 'list-style-image' to 'none':
>   #
>   # ul { list-style: none }
>   #
>   # The result is that no list-item marker is displayed. 
> but that doesn't make it clear whether this behavior of setting both
> to 'none' occurs only when there aren't values that are clearly one
> or the other, or whether any 'none' always applies to both
> properties and thus makes any values for either of the other cause
> the declaration to be rejected as an error.

Filed as CSS2.1 Issue 94
   http://wiki.csswg.org/spec/css2.1#issue-94

~fantasai

Received on Monday, 29 December 2008 23:28:47 UTC