title: Streaming large data files received over a websocket as a download
body: <p>I am receiving file data over a websocket and would like to present this to the user as a download. </p>
  
  <p>One solution would be to build a blob and use <code>URL.createObjectURL</code> once the entire file has been received. However I would prefer to start streaming the bytes received immediately to the user (as a standard download) rather than waiting for the whole file to be received first. </p>
  
  <p>This would be especially important for large files.</p>