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[stream-api] Editor's Draft for Streams API

From: Adrian Bateman <adrianba@microsoft.com>
Date: Wed, 14 Dec 2011 00:52:04 +0000
To: "Web Applications Working Group WG (public-webapps@w3.org)" <public-webapps@w3.org>
CC: Feras Moussa <ferasm@microsoft.com>
Message-ID: <6895C7B67488C14AA23F0E079F0D7E8F192F5C@TK5EX14MBXC284.redmond.corp.microsoft.com>
Following the discussion we had at TPAC [1], we have uploaded our draft as
an editor's draft to Mercurial:

http://dvcs.w3.org/hg/streams-api/raw-file/tip/Overview.htm

This is just a starting point for discussion and we're looking forward to
incorporating feedback as we move forward. We know there are a few things
that need to sync with other specs and Feras is working on that.

Thanks,

Adrian.

[1] http://www.w3.org/2011/11/01-webapps-minutes.html#item02


On Thursday, September 22, 2011 11:35 AM, I wrote:
> There has been discussion in this group now and again about the need for
> stream
> support as part of the File APIs including recently in the threads about
> Streaming
> Blobs [1] and XHR streaming [2]. I've also had several private
> conversations with
> members of the WG about the need we see for this kind of stream support.
> 
> Initially, we thought that supporting a streaming Blob was the correct
> solution
> but we ran into a number of issues with this as we investigated further.
> First of
> all, people were confused about using the term "Blob" to represent
> something of
> unknown size. Secondly, we received guidance from a number of people to
> keep the
> two concepts of Blob and Stream separate.
> 
> Back in March, we provided some suggestions about using streams in the
> context of
> Media Capture and Speech with our submission to the HTML Speech XG [3].
> Specifically at that time we said:
> 
>   We propose the addition of a stream type. While this document does
>   not present a detailed design for this type, we assume a Stream is
>   an object that:
> 
>     1. Has a content type;
>     2. Has unspecified length;
>     3. Can generally be used in the same places Blob can be used, for
>        example URL.createObjectURL().
> 
> Over the last six months, we have refined our thinking further and would
> like to
> submit a proposal for review by the working group that provides that
> detailed
> design. We believe that this work is part of the chartered deliverables
> for File
> API (and includes XHR support):
> 
>     Streams API - http://html5labs.com/streamsapi/
> 
> We recognise that there are a number of different proposals for using
> stream-like
> objects elsewhere in the web platform, usually for very specific use
> cases. What
> we have tried to define here is a Stream object that is as generic as the
> Blob
> object defined in the File API spec.
> 
> As we started building applications with richer access to devices on the
> system
> including files we found the lack of support for an object representing
> asynchronous data of (initially) unknown size was important. Section 11 of
> the
> proposal provides examples of the scenarios we have in mind. To start to
> address
> this gap, we have implemented a preview of this mechanism in IE10 Platform
> Preview 3 behind a vendor prefix (e.g. MSStream) to gain more
> implementation
> experience.
> 
> We look forward to hearing feedback on this proposal, which we've framed
> mostly
> as a delta against existing drafts in this working group.
> 
> Thanks,
> 
> Adrian.
> 
> [1] http://lists.w3.org/Archives/Public/public-
> webapps/2011JulSep/0725.html
> [2] http://lists.w3.org/Archives/Public/public-
> webapps/2011JulSep/0741.html
> [3] http://lists.w3.org/Archives/Public/www-archive/2011Mar/att-
> 0001/microsoft-api-draft-final.html#streams
> 
> 
> 
> 
Received on Wednesday, 14 December 2011 00:52:38 GMT

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