On Fri, Sep 20, 2013 at 2:10 AM, Simon Pieters <simonp@opera.com> wrote: > On Fri, 20 Sep 2013 09:32:41 +0200, Glenn Adams <glenn@skynav.com> wrote: > > But cue instanceof RawCue && ! cue instanceof TTMLCue would work. >> > > The argument was that if authors expect `cue instanceof RawCue` to mean > that the UA doesn't render it, we shouldn't break that expectation. It > doesn't matter that there are other ways to check it. For instance, you > could do cue.__proto__ == RawCue.prototype. > Backward compatibility with current usage doesn't seem to be a strong consideration here given other changes being made, e.g., removing TextTrackCue constructor. > > That said, your code doesn't actually work, for two reasons. (1) the `!` > negates `cue`, not `cue instanceof TTMLCue`. Right, wrap in parens, but you got the idea. > (2) The UA might support other formats than TTMLCue that inherit from > RawCue if TTMLCue sets such a precedent. Right. In any case, using cue type to imply UA renderability or rendering behavior is probably a poor design for exposing those behaviors.
Received on Friday, 20 September 2013 17:41:36 UTC