Snippet for ajax file uploading

ajax-file-upload.js

document.getElementById('form').addEventListener('submit', function(e) {
    var form = this,
        files = document.getElementById('file').files;

    var reader = new FileReader();
    reader.onloadend = (function(file) {
        return function(e) {
            if (e.target.readyState == FileReader.DONE) {
                document.getElementById('file-contents').value = btoa(e.target.result);
                document.getElementById('file-name').value = escape(file.name);

                $.ajax({
                    url: form.getAttribute('action'),
                    type: 'post',
                    data: $(form).serialize(),
                    context: document.body
                }).done(function(response) {
                    console.log(location.href, response);
                    var span = document.createElement('span');
                    span.innerHTML = ['<img class="thumb" src="', location.href, response, '"/>'].join('');
                    document.getElementById('form').insertBefore(span, null);
                });
            }
        }
    })(files[0]);

    reader.readAsBinaryString(files[0].slice(0, files[0].size - 1));
    e.preventDefault();
    return false;
});