- From: Eric Uhrhane <ericu@google.com>
- Date: Wed, 10 Mar 2010 18:32:35 -0800
- To: Mike Clement <mikec@google.com>
- Cc: public-device-apis@w3.org
On Mon, Mar 8, 2010 at 6:30 PM, Mike Clement <mikec@google.com> wrote: > This is starting to look very useful. I do have a couple of questions/comments: > > 1) It might be useful for the FileWriter::write method to return the > number of bytes written so that it more closely matches other common > file APIs (e.g., fwrite). Of course that value is often only used for > detecting the error of "not writing as many bytes as expected", which > I assume in FileWriter will cause an explicit onerror() invocation. > It still might be useful for statistics gathering and/or logging, > though. You can get this information from the length/position members on error, and you can keep track of it as it happens via progress events. Also, I think it may be less needed with this API, given that it only writes data of a known size [the Blob]. With APIs that do data type conversions or expand line endings on write, it might be more important. > 2) I agree with the comment by annevk@opera.com that BlobBuilder > should have overloaded append() methods. In fact, I believe that > BlobBuilder needs more functionality in this regard, especially when > it comes to getting non-textual data into a Blob. It looks like > appendBlob() is meant to address the need of acquiring binary data, > but it's looking to me that the only way to get binary data into a > Blob in the first place is by reading it from a file. One can easily > imagine a scenario where you have an image element (JPG) and want to > put its bytes into a Blob and save it out to a file. It would be > inefficient to require the data to be encoded into a string just to > save it out, but I don't see another pathway right now. Are there > other Blob acquisition/manipulation techniques out there that I'm > missing? I guess what I'm saying is that I might want to capture any > number of interesting elements as binary data and save them to disk, > but it's unclear to me whether or not the browser development > community is embracing the concept of the Blob as a first class > citizen such that I can expect to access elements as binary where > those sources are binary to begin with (e.g., images, video, audio). I've converted the append() methods to overload as Anne recommended. I've seen discussions of making a way to get a Blob from a Canvas or an XHR response body; it's a natural extension. > Looking forward to more File API developments! > > --Mike > > >
Received on Thursday, 11 March 2010 02:33:25 UTC