Re: Visibility API

   yup, I believe Chrome will run scripts for rel=prefetch. More
specifically, it is "prerender" instead of prefetch.
   http://code.google.com/p/chromium/issues/detail?id=61745

<http://code.google.com/p/chromium/issues/detail?id=61745>  So the
visibility api has dependencies on the implementation of rel=prefetch.

cheer,
Zhiheng

On Wed, Feb 16, 2011 at 10:57 AM, Christian Biesinger
<cbiesinger@gmail.com>wrote:

> link rel=prefetch doesn't execute any scripts on the prefetched page,
> at least not in Firefox. Is this different in chrome?
>
> This does seem like a useful API for web pages though.
>
> -christian
>
> On Wed, Feb 16, 2011 at 6:30 AM, Arvind Jain <arvind@google.com> wrote:
> > Hi webperf folks,
> > I'd like to check with you if it would make sense to add one more
> > deliverable to the web performance working group.
> > There's been a proposal for a Tab Visibility API, which provides a web
> > developer an API (in Javascript) to find out whether the page is
> currently
> > hidden (e.g. not in the foreground tab) vs. visible to the user.
> > I'm aware of two performance use cases for it:
> > 1) pages that consume a lot of CPU can avoid doing so when the page is
> not
> > visible to the user.
> > 2) support html5 <link rel=prefetch> standard (when the browser
> prefetches a
> > page, it should let the page know it's not visible).
> > Below is the discussion on it on whatwg:
> >
> http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2010-December/029382.html
> > I think it makes sense for web performance working group to standardize
> this
> > API. Please let me know your thoughts.
> > Thanks,
> > Arvind
>
>