W3C home > Mailing lists > Public > public-webapps@w3.org > October to December 2011

Re: [FileAPI] FileReader.abort() and File[Saver|Writer].abort have different behaviors

From: Jonas Sicking <jonas@sicking.cc>
Date: Wed, 2 Nov 2011 15:56:50 -0700
Message-ID: <CA+c2ei-JGWfdooF+vwtB5MxqJQv_9EBAHSkZ4vW3fQaiqUjZ3Q@mail.gmail.com>
To: Eric U <ericu@google.com>
Cc: Glenn Maynard <glenn@zewt.org>, Anne van Kesteren <annevk@opera.com>, arun@mozilla.com, Kyle Huey <me@kylehuey.com>, public-webapps@w3.org
On Wed, Nov 2, 2011 at 9:56 AM, Eric U <ericu@google.com> wrote:
> On Mon, Oct 3, 2011 at 6:13 PM, Jonas Sicking <jonas@sicking.cc> wrote:
>> On Mon, Oct 3, 2011 at 5:57 PM, Glenn Maynard <glenn@zewt.org> wrote:
>>> On Mon, Oct 3, 2011 at 8:10 PM, Jonas Sicking <jonas@sicking.cc> wrote:
>>>>
>>>> 1. Make "loadend" not fire in case a new load is started from
>>>> onabort/onload/onerror. Thus "loadend" and "loadstart" isn't always
>>>> paired up. Though there is always a "loadend" fired after every
>>>> "loadstart".
>>>> 2. Make FileReader/FileWriter/FileSaver not behave like XHR. This also
>>>>
>>>> leaves the problem unsolved for XHR.
>>>>
>>>> Are there other options I'm missing?
>>>
>>> Or do both, improving XHR as much as backwards-compatibility allows and
>>> don't try to match other APIs to it exactly.  I'd much prefer weirdness be
>>> isolated to XHR than be perpetuated through every PE-based API.
>>
>> So what exactly are you proposing we do for XHR and for FileReader/FileWriter?
>>
>> I'm still not convinced that it's better for authors to require them
>> to use setTimeout to start a new load as opposed to let them restart
>> the new load from within an event and cancel all following events. I
>> agree that this introduces some inconsistency, but it only does so
>> when authors explicitly reuses a FileReader/XHR/FileWriter for
>> multiple requests.
>>
>> And it only weakens the invariant, not removes it. So instead of
>>
>> * There's exactly one 'loadend' event for each 'loadstart' event.
>>
>> we'll have
>>
>> * There's always a 'loadend' event fired after each 'loadstart' event.
>> However there might be other 'loadstart' events fired in between.
>
> I'm for this.  It lets FileReader and FileWriter match XHR, avoids [in
> the odd case] long strings of stacked-up loadend events, and users can
> avoid all the issues either by creating a new FileReader or by
> wrapping nested calls in timers if they care.  I believe Jonas is in
> favor of this as well.
>
> Can we put this one to bed?

So the proposal here is to allow new loads to be started from within
abort/error/load event handlers, and for "loadend" to *not* fire if a
new load has already started by the time the abort/error/load event is
done firing. And the goal is that XMLHttpRequest, FileReader and
FileWriter all behave this way. Is this correct?

If so, I agree that this sounds like a good solution.

/ Jonas
Received on Wednesday, 2 November 2011 22:57:59 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 18:49:48 GMT