[whatwg] Proposing <canvas>.toBlob(contentType)

Kyle Huey me at kylehuey.com
Wed Apr 13 15:02:07 PDT 2011

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

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