7:03 p.m.
I have an Ajax request that pulls an image from a web service. I'm using
f:ajax's onevent attribute to display a progress bar when the Ajax call
begins, and make it disappear when the call is complete, but complete does
not coincide with the end of rendering, so there's sometimes a considerable
lag between when the progress bar disappears, and when the image is fully
drawn.
Is there a way to send a notification when rendering is complete, so I can
avoid the lag time?
Thanks,
david
7:40 p.m.
You know, that's a really good question - I don't think we considered
that use case. Probably because we were expecting the rendering process
itself to not take a really noticeable amount of time. Other than
rendering a new image component, or a complex canvas, or a really
complex table, I can't imagine it taking all that long - what are you
rendering?
(If it's just a single image tag that's rendering, you could always do a
onload attribute on that element...)
Though I haven't tested it, I think that a rendered event isn't going to
help you anyway if it's an image, since the image itself will be loaded
out of band (I think) after the DOM is updated, and the rendered event
will have long before fired off... more or less mimicking what you're
already seeing.
Jim
On 5/24/09 5:03 PM, David Geary wrote:
I have an Ajax request that pulls an image from a web service.
I'm using
f:ajax's onevent attribute to display a progress bar when the Ajax call
begins, and make it disappear when the call is complete, but complete
does not coincide with the end of rendering, so there's sometimes a
considerable lag between when the progress bar disappears, and when the
image is fully drawn.
Is there a way to send a notification when rendering is complete, so I
can avoid the lag time?
Thanks,
david
9:06 p.m.
On Sun, May 24, 2009 at 8:40 PM, Jim Driscoll <Jim.Driscoll(a)sun.com> wrote:
You know, that's a really good question - I don't think we
considered that
use case. Probably because we were expecting the rendering process itself
to not take a really noticeable amount of time. Other than rendering a
new image component, or a complex canvas, or a really complex table, I can't
imagine it taking all that long - what are you rendering?
(If it's just a single image tag that's rendering, you could always do a
onload attribute on that element...)
Though I haven't tested it, I think that a rendered event isn't going to
help you anyway if it's an image, since the image itself will be loaded out
of band (I think) after the DOM is updated, and the rendered event will have
long before fired off... more or less mimicking what you're already seeing.
I believe you are describing the situation perfectly. The rendering of the
image is really not part of the Ajax request at all. The main issue is that
the onload even of an image was never standardized in HTML (to my
knowledge), which is such a pain point of HTML. However, I do know that it
works in most browsers.
-Dan
--
Dan Allen
Senior Software Engineer, Red Hat | Author of Seam in Action
http://mojavelinux.com
http://mojavelinux.com/seaminaction
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10:14 p.m.
We talked about many of these Ajax callback events. I believe it's
specified that the "complete" event happens
upon receiving some status from the xmlhttprequest call (success or
failure) but before dom update.
-roger
David Geary wrote:
I have an Ajax request that pulls an image from a web service.
I'm
using f:ajax's onevent attribute to display a progress bar when the
Ajax call begins, and make it disappear when the call is complete, but
complete does not coincide with the end of rendering, so there's
sometimes a considerable lag between when the progress bar disappears,
and when the image is fully drawn.
Is there a way to send a notification when rendering is complete, so I
can avoid the lag time?
Thanks,
david
6179
days inactive
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days old
jsr-314-open-mirror@lists.jboss.org
3 comments
4 participants
participants (4)
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Dan Allen -
David Geary -
Jim Driscoll -
Roger Kitain