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Re: File API Feedback

From: Michael Nordman <michaeln@google.com>
Date: Tue, 21 Jul 2009 18:28:32 -0700
Message-ID: <fa2eab050907211828k8d8ab84l201bb70ddff307a3@mail.gmail.com>
To: arun@mozilla.com
Cc: public-webapps@w3.org
On Tue, Jul 21, 2009 at 6:20 PM, Arun Ranganathan <arun@mozilla.com> wrote:

> Michael Nordman wrote:
>
>> The BlobBuilder.append() method is central to the use-case I'm referring
>> to.
>> builder.append(string data that comprises the multipart/form-data header);
>> builder.append(string data that comprises simple text part);
>> builder.append(string data that comprises the start of a binary part);
>> builder.append(fileBlob); // the file itself
>> builder.append(string data that closes the binary part);
>> // perhaps more binary and text parts
>> builder.append(string data that closes the multipart/form-data);
>> multipartBlob = builder.getAsBlob();
>>
>>
> OK, I understand your use case much better now :)
>
> So, currently, we provide a fileData.getAsText(fileCallback, encoding,
> error)
>
> and
>
> within fileCallback (a callback function) you can get the file's data as a
> string (say a UTF-8 encoded string, or any encoding specified by
> "encoding"); it is passed as an argument to fileCallback.
>
> Then, you can append to the string (or prepend, in the case of the header)
> using the standard JavaScript string methods.  And you can, of course, post
> the string via XHR.
>
> Along with a similarly asynchronous splice method to generate "ranged"
> subsets of a FileData object, I think that we've got *most* of the features
> exposed by both BlobBuilder and Blob.


I don't follow... how would you use the FileData and XHR2 apis to do what I
outlined with blob builder... can you show me in a similar amount of pseudo
code?


>
>
> Have I missed something important?
>
>>
>> Splice doesn't come into play for the use case described above. The
>> motivation for the .splice method is to "chunk" very large files into many
>> parts, and to upload them individually... think large YouTube videos
>>
> Understood.  That is why I am adding it to the specification :-)
>
> -- A*
>
>
Received on Thursday, 23 July 2009 05:50:53 GMT

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