これを試してください:http://jsfiddle.net/vpnQe/
自由に遊んでください。あなたのニーズに役立つことを願っています:)
コード
var URL = window.webkitURL || window.URL;
var BlobBuilder = window.WebKitBlobBuilder || window.MozBlobBuilder || window.BlobBuilder;
var url;
$("button").click(function() {
if (url) URL.revokeObjectURL(url);
var bb = new BlobBuilder();
bb.append("it works!");
var file = bb.getBlob("text/plain");
url = URL.createObjectURL(file);
$("a[download]").attr("href", url);
var evt = document.createEvent('MouseEvents');
evt.initMouseEvent('click', true, true, window, 1, 0, 0, 0, 0, false, false, false, false, 0, null);
$("a[download]")[0].dispatchEvent(evt);
});
HTML
<article>
<button type="button">create url, put it in below link, and click it</button><br/>
<a download="test.txt">Download as text.txt</a>
</article>
<footer>
<ul>
<li><a href="https://developer.mozilla.org/en/Document_Object_Model_(DOM)/window.URL.createObjectURL">window.URL.createObjectURL</a></li>
<li><a href="http://updates.html5rocks.com/2011/08/Downloading-resources-in-HTML5-a-download">a[download]</a></li>
</ul>
</footer>