how do you upload a filestream/buffer in winrt html/JavaScript?

Question

I want to read a file from local storage and upload it via ajax. How is this done?

Not sure if it's what you're asking for, but have you considered `` (http://stackoverflow.com/questions/166221/how-can-i-upload-files-asynchronously?rq=1)? Web pages can't otherwise read local storage because they are sandboxed AFAIK. — CoconutFred, Aug 16 '16 at 22:21

score 0 · Answer 1 · answered Aug 16 '16 at 22:36

In most browsers, you can use FileReader to read data from file inputs. There are various functions for reading the data; this example uses the function that returns an ArrayBuffer containing all the bytes:

<script>
  window.onload = function() {
    document.getElementById('upload').onchange = function(e) {
      var file = e.target.files[0];
      var fileReader = new FileReader();
      fileReader.onload = function(e) {
        var bytes = e.target.result;
        console.log(bytes);
      };
      fileReader.readAsArrayBuffer(file);
    };
  };
</script>
<input type = 'file' id = 'upload' />

Thanks for the info, but the solution needed must be specific to winrt — Matt, Sep 27 '16 at 18:48

score 0 · Accepted Answer · answered Aug 17 '16 at 00:29

I managed to figure it out. Here's the code for anyone interested.

var form = new FormData();
            form.append("data", angular.toJson(message));
            var bytes = new Uint8Array(audio.length); //audio is an IBuffer 
                var dataReader = Windows.Storage.Streams.DataReader.fromBuffer(audio);
                dataReader.readBytes(bytes);
                dataReader.close();

                var media = new Blob([bytes], { type: "application/octet-stream" }); //application/octet-stream or audio/mpeg?
                form.append("attached_files", media, "recording-aac.caf");

            return $http.post(AppSettings.baseUri + "api/sendmessage", form, { headers: { "Content-Type": undefined } });

how do you upload a filestream/buffer in winrt html/JavaScript?

2 Answers2