Re: Summary of calc serialization discussion

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?

Thanks,

Alan

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

Received on Tuesday, 5 April 2016 23:50:16 UTC