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Re: Not making partial result available during FileReader.readAsText()?

From: Jonas Sicking <jonas@sicking.cc>
Date: Mon, 12 Apr 2010 17:31:42 -0700
Message-ID: <s2n63df84f1004121731x690d6878v6bfab8594bb9d80f@mail.gmail.com>
To: Jian Li <jianli@chromium.org>
Cc: Michael Nordman <michaeln@google.com>, Web Applications Working Group WG <public-webapps@w3.org>
Unfortunately I think decoded data is impossible as you have no idea
what the total amount of decoded data will be until you've decoded the
entire file.

/ Jonas

On Mon, Apr 12, 2010 at 4:35 PM, Jian Li <jianli@chromium.org> wrote:
> This sounds good. I have one more question related to this.
> What are we going to set for total and loaded attributes for ProgressEvent?
> Is it based on the decoded text or the underlying binary data?
>
>
> On Fri, Apr 9, 2010 at 6:59 PM, Jonas Sicking <jonas@sicking.cc> wrote:
>>
>> I think the spec should say MUST here, rather than SHOULD. Streaming
>> contents seems as useful for text files as for binary files.
>>
>> The one thing that was tricky for us when implementing this was
>> charset detection. We can't really expose any data until we've decided
>> what charset to decode it with. However when loading normal pages over
>> http the same situation arises, and all major browsers support
>> streaming there.
>>
>> So I consider it a bug that firefox doesn't support this yet. It's
>> something we should fix.
>>
>> / Jonas
>>
>> On Fri, Apr 9, 2010 at 6:33 PM, Jian Li <jianli@chromium.org> wrote:
>> > Should we really want to support this? As I know, FF 3.6 does not
>> > support
>> > this in its current FileReader implementation. I just want to understand
>> > if
>> > there is a strong need for this.
>> >
>> > On Fri, Apr 9, 2010 at 5:49 PM, Michael Nordman <michaeln@google.com>
>> > wrote:
>> >>
>> >> Seems pretty clear from the snippet you provided, it says you SHOULD
>> >> provide partially decoded results in the result attribute as progress
>> >> is
>> >> made.
>> >>
>> >> On Thu, Apr 8, 2010 at 8:31 PM, Jian Li <jianli@chromium.org> wrote:
>> >>>
>> >>> For FileReader.readAsText, the spec seems to allow partial file data
>> >>> being decoded and saved in the result attribute when progress event is
>> >>> fired:
>> >>>
>> >>> Make progress notifications. As the bytes from the fileBlob argument
>> >>> are
>> >>> read, user agents SHOULD ensure that on getting, the result attribute
>> >>> returns partial file data representing the number of bytes currently
>> >>> loaded
>> >>> (as a fraction of the total) [ProgressEvents], decoded in memory
>> >>> according
>> >>> to the encoding determination.
>> >>>
>> >>> The partial file data read so far might not get decoded completely.
>> >>> Could
>> >>> we choose not to decode the partial result till we retrieve all the
>> >>> data,
>> >>> just like what FileReader.readAsDataURL does?
>> >>
>> >
>> >
>
>
Received on Tuesday, 13 April 2010 00:32:35 GMT

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