On 04/29/2013 11:42 AM, Robert O'Callahan wrote:
On Mon, Apr 29, 2013 at 8:56 PM, James Graham <jgra...@opera.com
<mailto:jgra...@opera.com>> wrote:
On 04/29/2013 05:26 AM, Robert O'Callahan wrote:
Also, this is a feature where it's trivial for applications to
gracefully
degrade on browsers that don't have the feature.
I'm not sure that's true. I mean, it's *possible* but you have to be
careful to never depend on anything that could happen after the
"natural" load event in e.g. your load event handler. I can quite
easily see people getting that wrong.
I'm not sure what you're getting at here.
I mean, let's say you delay the load event until after some data has
loaded over a web socket. If you try to use that data from the load
event handler it can fail in a racy way in UAs that don't support
delaying the load event. This also seems like the kind of race that you
are more likely to win on a local network, so it wouldn't necessarily be
caught during development.
In general this seems quite a scary design. The load event is rather
intimately tied in to the lifecycle of the document, and encouraging
people to arbitrarily delay it feels like a potential source of bugs
and confusion.
Adding new things that delay the load event has not been a source of
bugs and confusion in my experience. Authors do it a lot and we've done
it in specs too.
So far we have kept the model where the load event is auomatically
managed by the UA, rather than giving the developer direct control of it.
Is getting screenshots of pages for thumbnails really something that
needs an author-facing API? In general the concept of "fully loaded"
doesn't make any sense for a class of modern web applications, which
might keep loading content or changing their presentation across
their liefetime. Therefore it seems like simply taking one
screenshot at page load and replacing it with one a little later
after a timeout might be a good-enough solution.
The problem is when you next load the application. You don't want to
replace a good screenshot with a screenshot of the application saying
"Loading...".
Then don't replace the screenshot with one taken at the load-event time
if you already have one.
