Uploading an excel file in Ruby on Rails to open mobile devices???

Question

Android

Please tell me the universal code for uploading data to an excel file so that this file can be opened on PCs and smartphones!?
This is the code I currently have:
Controller:

headers['Content-Type'] = "application/vnd.ms-excel; charset=windows-1251"
headers['Content-Disposition'] = 'attachment; filename="subscribers.xls"'
headers['Cache-Control'] = ''

View:

<table>
<tr>...</tr>
</table>

This code only works on PC.

Answer 1

It's strange that it opens on your PC.
Use axlsx_rails gem to generate xls, or upload as CSV