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Re: Lazy Blob

From: Glenn Maynard <glenn@zewt.org>
Date: Wed, 1 Aug 2012 10:44:49 -0500
Message-ID: <CABirCh-F7+C2akr9cFsLQ2Zx0okupjvX29r9s8sbrtifU1szPA@mail.gmail.com>
To: Robin Berjon <robin@berjon.com>
Cc: WebApps WG <public-webapps@w3.org>, Jungkee Song <jungkee.song@samsung.com>
On Wed, Aug 1, 2012 at 9:59 AM, Robin Berjon <robin@berjon.com> wrote:

> var bb = new BlobBuilder()

,   blob = bb.getBlobFromURL("http://specifiction.com/kitten.png", "GET", {
> Authorization: "Basic DEADBEEF" });
> Everything is the same as the previous version but the method and some
> headers can be set by enumerating the Object. I *think* that those are all
> that would ever be needed.

We already have an API to allow scripts to make network requests: XHR.
 Please don't create a new API that will end up duplicating all of that.
 However this might be done, it should hang off of XHR.

Ideally, a new responseType could be added to XHR which operates like
"blob", except instead of reading the whole resource, it just performs a
HEAD to retrieve the response length and immediately returns the Blob,
which can be read to perform further Content-Range reads.  This sits
relatively cleanly within the XHR API.  It also has nice security
properties, as if you send that Blob somewhere else--possibly to a
different origin--it can do nothing with the Blob but read it as it was

The trouble is chunked responses, where the length of the resource isn't
known in advance, since Blobs have a static length and aren't designed for

Glenn Maynard
Received on Wednesday, 1 August 2012 15:45:20 UTC

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