Скачать програмно файл по ссылке (http://pixelscommander.com/javascript/javascript-file-download-ignore-content-type/)

downloadFile.js

window.downloadFile = function(url,name) {
    if (window.downloadFile.isChrome || window.downloadFile.isSafari) {
        var link = document.createElement('a');
        link.href = url;
        if (link.download !== undefined){
            var fileName = url.substring(url.lastIndexOf('/') + 1, url.length);
            link.download = name?name:fileName;
        }
        if (document.createEvent) {
            var e = document.createEvent('MouseEvents');
            e.initEvent('click' ,true ,true);
            link.dispatchEvent(e);
            return true;
        }
    }
    var query = '?download';
    window.open(sUrl + query, '_self');
}
window.downloadFile.isChrome = navigator.userAgent.toLowerCase().indexOf('chrome') > -1;
window.downloadFile.isSafari = navigator.userAgent.toLowerCase().indexOf('safari') > -1;