Thanks for the information. The "moz-blob" data type looks like it would
work, but I need a cross-browser solution in the near future, for new browsers
at least. It looks like I might need to fall back on a WebSocket solution with
a proprietary protocol between the WebSocket server and applications.
The annoying thing is that the W3C XMLHttpRequest() specification of
August 2009 contained exactly what I need:
The responseBody attribute, on getting, must return the result of
running the following steps:
If the state is not LOADING or DONE raise an INVALID_STATE_ERR
exception and terminate these steps.
Return a ByteArray object representing the response entity body or
return null if the response entity body is null.
Thus, for byteArray data one could access the partially delivered
response. For some reason a restriction was added later that removed this
capability, by changing "If the state is not LOADING or DONE" to "If the state
is not DONE" for all data types except "text". Alas. I still don't understand
why W3C and WHATWG added this restriction. Normally new releases of a standard
add capabilities, rather than taking them away. It is especially puzzling in
this situation, since it basically blows off the IETF RFC 7230 requirement that
HTTP clients must support chunked responses.
Regards, Gomer
--
Gomer Thomas Consulting, LLC
9810 132nd St NE
Arlington, WA 98223
Cell: 425-309-9933
-----Original Message-----
From: Jonas Sicking [mailto:jo...@sicking.cc]
Sent: Wednesday, March 16, 2016 1:01 PM
To: Gomer Thomas <go...@gomert-consulting.com>
Cc: Hallvord Reiar Michaelsen Steen <hst...@mozilla.com>; WebApps WG
<public-webapps@w3.org>
Subject: Re: [XHR]
Sounds like you want access to partial binary data.
There's some propitiatory features in Firefox which lets you do this
(added ages ago). See [1]. However for a cross-platform solution we're still
waiting for streams to be available.
Hopefully that should be soon, but of course cross-browser support
across all major browsers will take a while. Even longer if you want to be
compatible with old browsers still in common use.
[1]
https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/responseType
/ Jonas
On Wed, Mar 16, 2016 at 12:27 PM, Gomer Thomas
<go...@gomert-consulting.com> wrote:
> In my case the object being transmitted is an ISO BMFF file (as
a blob), and I want to be able to present the samples in the file as they
arrive, rather than wait until the entire file has been received.
> Regards, Gomer
>
> --
> Gomer Thomas Consulting, LLC
> 9810 132nd St NE
> Arlington, WA 98223
> Cell: 425-309-9933
>
>
> -----Original Message-----
> From: Hallvord Reiar Michaelsen Steen [mailto:hst...@mozilla.com]
> Sent: Wednesday, March 16, 2016 4:04 AM
> To: Gomer Thomas <go...@gomert-consulting.com>
> Cc: WebApps WG <public-webapps@w3.org>
> Subject: Re: [XHR]
>
> On Tue, Mar 15, 2016 at 11:19 PM, Gomer Thomas
<go...@gomert-consulting.com> wrote:
>
> > According to IETF RFC 7230 all HTTP recipients “MUST be able
to parse
> > the chunked transfer coding”. The logical interpretation of
this is
> > that whenever possible HTTP recipients should deliver the
chunks to
> > the application as they are received, rather than waiting for
the
> > entire response to be received before delivering anything.
> >
> > In the latest version this can only be done for “text”
responses. For
> > any other type of response, the “response” attribute returns
“null”
> > until the transmission is completed.
>
> How would you parse for example an incomplete JSON source to
expose an object? Or incomplete XML markup to create a document? Exposing
partial responses for text makes sense - for other types of data perhaps not so
much.
> -Hallvord
>
>
