jQuery File Download is a cross server platform compatible jQuery plugin that allows for an Ajax-like file download experience that isn't normally possible using the web.

http://jqueryfiledownload.apphb.com/

https://github.com/johnculviner/jquery.fileDownload/blob/master/src/Scripts/jquery.fileDownload.js

This might be a better solution to your problem https://github.com/eligrey/FileSaver.js/

• jQuery 1.6+

• Q: I need to send in custom headers. How do I do that?
  • Unfortunately since this plugin uses an iframe and not AJAX you cannot send in custom headers. If you really need to do this and are willing to accept a more narrow range of browser support this might be a better solution to your problem https://github.com/eligrey/FileSaver.js/
• Q: It doesn't work!?
  • Try out the demo and make sure you are doing exactly what it is doing: http://jqueryfiledownload.apphb.com/ If the demo doesn't work in your browser you have defintely found a bug and us know!
  • Due to iframe security restrictions you must serve up the file from the same domain you see in the address bar

• Internet Explorer 6+ - Works fine for standard use cases except in < IE9 JavaScript access to the failed response HTML doesn't (and can't) work reliably due to browser iframe constraints.
• Firefox 11+ - reasonably sure it will work on earlier versions
• Chrome 17+ - reasonably sure it will work on earlier versions
• iOS 5.0+ - reasonably sure it will work on earlier versions
• Android 4.0+ - non-GET requests do not work due to a long-standing bug in the Android browser. This is handled 'gracefully' with a message to the user.

http://johnculviner.com/post/2012/03/22/Ajax-like-feature-rich-file-downloads-with-jQuery-File-Download.aspx

bower install jquery-file-download -S

https://github.com/johnculviner/jquery.fileDownload/blob/master/src/Common/FileDownloadAttribute.cs
The above attribute can be used on any controller action that may return a file download that you would like to use jquery.fileDownload.js with

http://johnculviner.com/category/jQuery-File-Download.aspx

https://github.com/johnculviner/jquery.fileDownload/blob/master/src/Scripts/jquery.fileDownload.js

The jquery_file_download-rails gem integrates jquery.fileDownload.js into the Rails 3.1+ asset pipeline.

https://github.com/seiko777/PHP-jquery-downloader