Get binary data with XMLHttpRequest in a Firefox extension

Question

I'm trying to download some binary data from my Firefox extension. When I try to set a created XMLHttpRequest to arraybuffer mode:

oHTTP = new XMLHttpRequest();   
oHTTP.responseType = "arraybuffer";

The error

InvalidStateErr
An attempt was made to use an object that is not, or is no longer, usable

is thrown.

Is there another way to download binary data in a Firefox extension?

Answer 1

You must call the open method first.