JavaScript readAsBinaryString Function on E11

Question

In this page http://www.html5rocks.com/en/tutorials/file/dndfiles/ if you scroll down to example \"Example: Slicing a file. Try it!\" you will see uses of readAsBin

Answer 1

For IE 11 you can use this XHR trick:

function blobToBinaryStringIE11(blob) {
    var blobURL = URL.createObjectURL(blob);
    var xhr = new XMLHttpRequest;
    xhr.open("get", blobURL);
    xhr.overrideMimeType("text/plain; charset=x-user-defined");
    xhr.onload = function () {
        var binary = xhr.response;
        // do stuff
    };
    xhr.send();
}

It's 20x faster than the Uint8Array + fromCharCode route and as fast as readAsBinaryString.