Send JavaScript data to Rails

Question

I have a JS code where I can capture, through an input button, the filename from the file(txt) I selected. How could I possibly send this filename to another view(I know I can't do this directly) and print it there(using puts, for example or any other method).

The JS code:

var fullPath = document.getElementById('file').value;
   if (fullPath) {
      var startIndex = (fullPath.indexOf('\\') >= 0 ? fullPath.lastIndexOf('\\') : fullPath.lastIndexOf('/'));
      var filename = fullPath.substring(startIndex);
      if (filename.indexOf('\\') === 0 || filename.indexOf('/') === 0) {
        filename = filename.substring(1);
      }
   }
   if(passAll === true){
   console.log(filename);
   }
}

You can disconsider the last if and concider just the console.log