- From: Michael Nordman <michaeln@google.com>
- Date: Mon, 26 Apr 2010 16:01:00 -0700
- To: Jonas Sicking <jonas@sicking.cc>
- Cc: Darin Fisher <darin@chromium.org>, Web Applications Working Group WG <public-webapps@w3.org>
- Message-ID: <z2qfa2eab051004261601z81d9bef2je5a952b58ec8dcce@mail.gmail.com>
On Mon, Apr 26, 2010 at 3:52 PM, Jonas Sicking <jonas@sicking.cc> wrote: > On Mon, Apr 26, 2010 at 3:39 PM, Darin Fisher <darin@chromium.org> wrote: > > On Mon, Apr 26, 2010 at 3:29 PM, Jonas Sicking <jonas@sicking.cc> wrote: > >> > >> On Mon, Apr 26, 2010 at 3:21 PM, Darin Fisher <darin@chromium.org> > wrote: > >> > There is some interest from application developers at Google in being > >> > able > >> > to get a Blob corresponding to the response body of a XMLHttpRequest. > >> > The use case is to improve the efficiency of getting a Blob from a > >> > binary > >> > resource downloaded via XHR. > >> > The alternative is to play games with character encodings so that > >> > responseText can be used to fetch an image as a string, and then use > >> > BlobBuilder to reconstruct the image file, again being careful with > the > >> > implicit character conversions. All of this is very inefficient. > >> > Is there any appetite for adding a responseBlob getter on XHR? > >> > >> There has been talk about exposing a responseBody property which would > >> contain the binary response. However ECMAScript is still lacking a > >> binary type. > >> > >> Blob does fit the bill in that it represents binary data, however it's > >> asynchronous nature is probably not ideal here, right? > >> > >> / Jonas > > > > > > I think there are applications that do not require direct access to the > > response data. > > For example, > > 1- Download a binary resource (e.g., an image) via XHR. > > 2- Load the resource using Blob.URN (assuming URN moves from File to > Blob). > > It may be the case that providing direct access to the response data may > be > > more > > expensive than just providing the application with a handle to the data. > > Consider > > the case of large files. > > Ah, so you want the ability to have the XHR implementation stream to > disk and then use a Blob to read from there? If so, you need more > modifications as currently the XHR implementation is required to keep > the whole response in memory anyway in order to be able to implement > the .responseText property. > > So we'll need to add some way for the page to indicate to the > implementation "I don't care about the .responseText or .responseXML > properties, just responseBlob" > Not sure we need additional API for that. If the page doesn't access those properties, its indicating that it doesn't need them. > > / Jonas > >
Received on Monday, 26 April 2010 23:01:28 UTC