(Following is a late but complete answer)
FileReader.readAsBinaryString()
is deprecated. Don't use it! It's no longer in the W3C File API working draft:
void abort();
void readAsArrayBuffer(Blob blob);
void readAsText(Blob blob, optional DOMString encoding);
void readAsDataURL(Blob blob);
NB: Note that File
is a kind of extended Blob
structure.
Mozilla still implements readAsBinaryString()
and describes it in MDN FileApi documentation:
void abort();
void readAsArrayBuffer(in Blob blob); Requires Gecko 7.0
void readAsBinaryString(in Blob blob);
void readAsDataURL(in Blob file);
void readAsText(in Blob blob, [optional] in DOMString encoding);
The reason behind readAsBinaryString()
deprecation is in my opinion the following: the standard for JavaScript strings are DOMString
which only accept UTF-8 characters, NOT random binary data. So don't use readAsBinaryString(), that's not safe and ECMAScript-compliant at all.
We know that JavaScript strings are not supposed to store binary data but Mozilla in some sort can. That's dangerous in my opinion. Blob
and typed arrays
(ArrayBuffer
and the not-yet-implemented but not necessary StringView
) were invented for one purpose: allow the use of pure binary data, without UTF-8 strings restrictions.
XMLHttpRequest.send()
has the following invocations options:
void send();
void send(ArrayBuffer data);
void send(Blob data);
void send(Document data);
void send(DOMString? data);
void send(FormData data);
XMLHttpRequest.sendAsBinary()
has the following invocations options:
void sendAsBinary( in DOMString body );
sendAsBinary() is NOT a standard and may not be supported in Chrome.
So you have several options:
send()
the FileReader.result
of FileReader.readAsArrayBuffer ( fileObject )
. It is more complicated to manipulate (you'll have to make a separate send() for it) but it's the RECOMMENDED APPROACH.send()
the FileReader.result
of FileReader.readAsDataURL( fileObject )
. It generates useless overhead and compression latency, requires a decompression step on the server-side BUT it's easy to manipulate as a string in Javascript.sendAsBinary()
the FileReader.result
of FileReader.readAsBinaryString( fileObject )
MDN states that:
The best way to send binary content (like in files upload) is using ArrayBuffers or Blobs in conjuncton with the send() method. However, if you want to send a stringifiable raw data, use the sendAsBinary() method instead, or the StringView (Non native) typed arrays superclass.