Question

I’m working on a project built entirely in node.js and coffeescript. I want to allow the user to export a CSV of several different collections in my Mongo DB by clicking a button on my website.
I believe the best way to do this would be to make an ajax call to my node.js backend and have that call return somefile.csv to the user. I’m at a loss at how to do this though, and there are so many conflicting resources. Here’s the stub of how I think things should work:

exports.exportToCSV = (req, res) ->
  console.log 'Inside exportToCSV'

  # Create a dynamic csv file
  # How to?
  # Set the response headers
  # How to? 
  # Attach the newly created CSV
  # How to?
  # Write the response
  res.write('somefile.csv')
  res.end()

Any help would be greatly appreciated. Thank you.

Answer 1

If you’re using Express (and I’d say you need a pretty big excuse not to), everything after creating the CSV is a piece of cake:

res.download 'somefile.csv'

As the Express docs explain, that’s shorthand for

res.attachment 'somefile.csv'

(which sets the headers) and

res.sendfile 'somefile.csv'

If you want to understand how it all works, here’s the source: https://github.com/visionmedia/express/blob/master/lib/response.js

As to creating a CSV, I’ve never had to do this, but you can’t go wrong searching npm for “csv”.