Open a blob in a browser tab

viewBlob.js

var xhr = new XMLHttpRequest();
xhr.open('GET', url, true);
xhr.responseType = 'blob';
xhr.onload = function(e) {
    if (this.status == 200) {
        // Return the blob and set the contentType
        // Note: .response instead of .responseText
        var _viewBlob = function(data, contentType) {
            var file = new Blob([data], {
                type: contentType
            });
            // IE won't allow opening a Blob with window.open()
            if (window.navigator && window.navigator.msSaveOrOpenBlob) {
                window.navigator.msSaveOrOpenBlob(file);
            } else {
                var fileURL = URL.createObjectURL(file);
                window.open(fileURL, '_blank');
            }
        };

        _viewBlob(this.response, contentType);

    } else {
        alert('Notice', 'Sorry, there was a problem retrieving the blob. Please try again later.')
    }
};

xhr.send();