I would be in favor of this. In my recent app — http://mustachified.com — I used `mozGetAsFile` to retrieve file from canvas, append it to form data and send to an external service via cross-domain request.
When mozGetAsFile was not available, I had to build blob manually from canvas' data url. Aside from the fact that it's more code to transfer/maintain, and (likely) worse performance, the blob building also relies on presence of BlobBuilder, ArrayBuffer and Uint8Array — so is not always available. Source: http://mustachified.com/master.js -- kangax On Wed, Apr 13, 2011 at 6:02 PM, Kyle Huey <m...@kylehuey.com> wrote: > Hello All, > > Gecko 2.0 ships with a non-standard method on <canvas> named > mozGetAsFile(contentType, fileName). We added this for internal use in our > UI. It retrieves the contents of the canvas as a File object (at the time > Gecko did not supports Blobs) encoded in the contentType according to the > same rules toDataURL uses. > > I propose adding a toBlob(contentType) method to the canvas element in the > style of toDataURL. This would greatly increase the options available to > developers for extracting data from a canvas element (a Blob can be saved > to > disk, XHRed, etc.) > > - Kyle >