Question

I’m writing a binary string from the server like this:

header('Content-type: application/octet-stream');
echo $data = pack('C*', 0, 10, 100, 127, 128, 200, 250, 255, 256);

and reading it with js and jDataView lib this way:

$.get('/get', function(text) {
    var view = new jDataView(text);

    for (var i = 0; i < 20; i++) {
        console.log(i, view.getUint8(i));
    }
});

The problem is that I can only read the values that are less than 128. jDataView uses getCharCode at to read Uint and it returns 65533 for each of the bigger values.

How to I get the values in js?

Answer 1

It works just fine when you change the headers sent (by PHP file) with…

header('Content-Type: text/plain; charset=x-user-defined')

Without this header (and tweaking of how XHR response should be processed; this article describes the process in details) it’s the text value that becomes messed up: all ‘invalid’ (> 127) characters will be literally replaced by '\uFFFD' ones.

Of course, it’s not possible to extract the original values from these characters, so it’s not a bug of jDataView, in my opinion.