On Jul 2, 2014, at 8:07 AM, Adam Barth <[email protected]> wrote: > On Tue, Jul 1, 2014 at 8:52 PM, Boris Zbarsky <[email protected]> wrote: >> On 7/1/14, 9:13 PM, Brendan Eich wrote: >>> Are you sure? Because Gecko has used XBL (1) to implement, e.g., <input >>> type=file>, or so my aging memory says. >> >> We use XBL to implement <marquee>. > > I'm working on using web components to implement <marquee> in Blink: > > https://github.com/abarth/marquee > > I've studied the XBL implementation of <marquee> in Gecko, and it does > leak some implementation details. As a simple example, > alert(document.createElement('marquee')) in Firefox says "[object > HTMLDivElement]" because the XBL implementation uses a div. > > The approach I'm using is roughly the one outlined by Maciej in [1]. > The most challenging aspect by far is isolating the script interface > inside and outside the component. > > If you ignore script isolation, we already know that the current > design of shadow DOM can provide isolation by twiddling some internal > bits because we use shadow DOM in the engine to implement <details>, > <keygen>, <video>, <progress>, and several other elements. We could > expose an API to authors that would let them twiddle those same bits, > but I'm not sure we should do that without providing script isolation > of some form.
By "twiddling some internal bits", not exposing the said shadow roots on the element? > My sense from following this discussion is that there's been a lot of > talking about this subject and not very much coding. Hopefully I'll > learn something interesting by writing code that I can report back to > this group. I don't think we necessarily have to code anything in order to have a discussion in this mailing list. Correct me if I'm wrong but neither WebApps WG nor W3C has any sort of policy to mandate that we need to create a polyfill or prototype in order to write a working draft for example as far as I know. Having said that, gaining implementation experience is definitely valuable, and I look forward to hearing what you find out with your work. - R. Niwa
