Re: [css-cascade] Naming "value of a declaration", renaming "specified value"

On 06/24/2013 02:16 PM, Tab Atkins Jr. wrote:
> The term "specified value" has always been confusing, because it does
> *not* refer to the value the author specified.  Instead, it's always
> referred to the value that starts the standard value-computation
> chain, at the point where a given element has a value for every
> property.
>
> Ironically, we don't actually *have* a term for the value the author
> actually specified in the stylesheet, or the close-enough concept of
> what CSSStyleDeclaration returns.
>
> Private conversation with dbaron (in #css) led to the following suggestions:
>
> 1. Use "declared value" for the value of a declaration; that is, what
> is returned when you query CSSStyleDeclaration.  This is not
> associated with any particular element, and may not have a value for
> every property.
>
> 2. Drop the term "specified value", and slightly modify Cascade so
> that "cascaded value" fills the role.  This just requires us to
> slightly change the verbiage around how we handle the global keywords;
> currently, the "cascaded value" may be empty or resolve to one of the
> global keywords.  We'd change it so that as part of the computation of
> the cascaded value, we guarantee that we fill in a value, and resolve
> away the global keywords.  (Our current use of "cascaded value" in the
> spec is unobservable from the outside, and we can just lean on the
> term "result of the cascade" to represent the value that might be
> empty or might be a global keyword.)
>
> Thoughts?

I'd like to point out that your proposed definition subsumes inheritance
into the term "cascaded". But cascading and inheritance are separate
processes. This is already poorly-understood by authors, and I don't
think it's a good idea to make our specs *also* conflate the two.

If "specified value" is confusing and we want a better term, ok,
let's add a new term that is clearer. But imo, us "cascaded value"
for this purpose is not clearer.

(I'll note that the terms, as chosen, made more sense in CSS2.0.
Right now, I agree, the value stages terminology is a bit of a mess.)

~fantasai

Received on Wednesday, 26 June 2013 17:46:03 UTC