Re: Summary of calc serialization discussion

On Wed, Apr 6, 2016 at 9:49 AM Alan Stearns <stearns@adobe.com> wrote:

> On 4/5/16, 2:50 PM, "Alan Stearns" <stearns@adobe.com> wrote:
>
> >On 4/5/16, 2:40 PM, "Shane Stephens" <shans@google.com> wrote:
> >>
> >> On Wed, Apr 6, 2016 at 7:24 AM Alan Stearns <stearns@adobe.com> wrote:
> >> >
> >> > Hey all,
> >> >
> >> > Here’s my stripped-down analysis of what’s been discussed so far:
> >> >
> >> > A. There is a benefit (for authors and developers) to simplifying
> >> > the specified value of calc for the Typed OM.
> >> >
> >> > B. There is a benefit (for debuggers and editors) for retaining the
> >> > actual string in the specified value.
> >> >
> >> > C. Browsers currently do not agree on what to do with specified
> >> > calc() values. There is a benefit to interoperability, but there
> >> > has been no evidence presented that authors care about the current
> >> > differences.
> >> >
> >> > Here are some options I see.
> >> >
> >> > 1. Solving for A and C, we define serialization rules as proposed
> >> > two weeks ago, and ask browsers to converge in how their tools
> >> > represent specified values. This makes things worse for B
> >> >
> >> > 2. Solving for B and C, we stick to specified values as the specified
> >> > strings, and ask browsers to converge on that. This makes things worse
> >> > for A.
> >> >
> >> > 3. Solving for A alone, we could define that the Typed OM uses
> computed
> >> > value simplifications for its representation of specified calc()
> >> > values, and leave things as they are with C for now.
> >>
> >>
> >> By "computed value simplifications" you mean expression simplifications?
> >> Merging of values with like units, simplification of constants, etc?
> >
> >Yes – as far as I can tell, no one disagrees with having the proposed
> simplifications defined for the computed value. So we’d converge on a
> interoperable computed value that works for the Typed OM, and define that
> the Typed OM also uses those simplifications for the specified value.
> >
> >It would also be good if we could solve C outside of the Typed OM, but I
> think it’s a separate question we can set aside (for now) in favor of
> agreeing on a solution for A.
>
> Hmm - reading the current PositionValue [1] section in Typed OM, I see
> that there’s a bit of A and B in the Typed OM already. For specified values
> there the cssText attribute contains the specified string - no
> serialization is invoked. I think that makes perfect sense for all
> specified values. Could we extend that such that when you access cssText
> through CSSStyleRule.styleMap you always get the string from the stylesheet?
>

That section should probably say that you get the serialized string, though.

Cheers,
    -Shane


> Thanks,
>
> Alan
>
> [1] https://drafts.css-houdini.org/css-typed-om/#positionvalue-objects
>