title: Javascript for downloading csv file doesn't work in FireFox
body: <p>I've got a javascript for converting the data and save it as a csv file. It looks like this:</p>
  
  <pre><code>function downloadCSV(args) {
      var data, filename, link;
      var type = args.type;
      var fields = Object.keys(json_for_export[0]);
      var csv = json_for_export.map(function(row){
          return fields.map(function(fieldName){
              return '"' + (row[fieldName] || '') + '"';
              });
          });
     csv.unshift(fields);
     csv = csv.join('\r\n')
     if (csv == null) return;
     filename = 'csv' + '_' + args.filename || 'export.csv';
     if (!csv.match(/^data:text\/csv/i)) {
              csv = 'data:text/csv;charset=utf-8,' + '\uFEFF' + csv;
     }
     data = encodeURI(csv);
     link = document.createElement('a');
     link.setAttribute('href', data);
     link.setAttribute('download', filename);
     link.click();
  }
  </code></pre>
  
  <p>It works fine in Chrome Browser but doesn't work in Firefox. What can be a cause of the problem?
  A check into the console and the data is formatted well into a csv type.</p>