Javascript / jQuery - How to convert Media and Image data into binary text format

Question

I need to send a image/media through json, for that conversion needs to be done into text format. How can I achieve that through jQuery/ Javascript?

Answer 1

A few times already I read that jQuery doesn't provide functionality to download binary data and have it pass on to JavaScript as a string. Then I ran into this question. That got me thinking and I wrote a wrapper around $.ajax() looking like this (yes, it's simplified to show the main bits):

ajaxWrapper = function(url, dataType, callback, headers) {
    return $.ajax({
        url: url,
        dataType: dataType == "binary" ? "text" : dataType,
        mimeType: dataType == "binary" ? "text/plain; charset=x-user-defined" : undefined,
        headers: headers || {}
    }).done(function(data, status, jqXHR) {
        callback(data, status, jqXHR);
    });
}

And then in case you are dealing with Unicode the callback contains this line:

data = btoa(unescape(encodeURIComponent(data)));

or otherwise simply

data = btoa(data);

In other words if you read through the documentation of $.ajax() you simply add a dataType "binary".

Note that I use jQuery 1.7.1, but I don't see why it shouldn't work in later versions, too.