Re: Presentation: Why Polyfilling CSS Is Hard - followup to Extensible Web Summit - Berlin

Hi Julian,

For proposals to CSS, please consult the CSS mailing list www-style@w3.org.

Greetings,
Dirk

On Oct 16, 2014, at 11:55 PM, Julian Viereck <julian.viereck@googlemail.com> wrote:

> Hi all,
> 
> at the Extensible Web Summit in Berlin [1] was a discussion about why creating polyfills for CSS is hard or even impossible. As a followup, I've given a presentation about this topic at the Webtuesday Meetup in Zurich/Switzerland [2]. You can find the presentation on SpeakersDeck:
> 
>   Why Polyfilling CSS Is Hard
>   https://speakerdeck.com/jviereck/why-polyfilling-css-is-hard
> 
> The presentation was high level and look as example on creating polyfills for layout related CSS features (e.g. CSS Regions or the Grid Style Sheet project, which adds constraints to CSS).
> 
> Towards the end of the presentation I mentioned a few low-level bits that are missing in CSS and that might make polyfilling CSS easier. Basically, I was looking at existing features in CSS and tried to come up with lower level CSS features to express them in the hope that the new build foundation is useful for creating polyfills more easily. Here are my two ideas as a rough outline:
> 
> #1: GhostDom
> 
> CSS has the ability to create new "text boxes" using the "content" attribute. For me this feels like creating some "ghost dom" entries - they are not really visible in the DOM but their present is noticeable during rendering later on. Beside the "content" attribute you could think about the "background" attribute to also create a new "ghost dom" behind the current element, which then can contain an <img> tag to display a background image. The pseudo-elements via "::before" and "::after" could also be expressed via such "ghost dom", that are placed at the appropriate position related to the matched DOM entry.
> 
> #2: ShadowStyles
> 
> The idea for ShadowStyles came to me when thinking about the new ShadowDOM API. When creating a polyfill, it would be nice to create new properties, which then expand into existing properties. E.g. the "background" attribute triggers the creation of a GhostDom entry and adds a <img> in case a background image should be displayed.
> 
> Cheers,
> 
> - Julian
> 
> [1]: http://lanyrd.com/2014/extwebsummit-berlin/
> [2]: http://webtuesday.ch/meetings/20141014/
>

Received on Friday, 17 October 2014 04:55:28 UTC