Create text file (CSV) and then attach to email - iPhone app

How can I create a text file (an Excel开发者_开发知识库-compatible CSV file), add some text to it, and then attach it to an email - all in an iPhone app on the spot.

I've read from a text file before. I've also emailed in an app before. I just need to be able to put it all together, except this time write to a file and attach it to the email.

How can this be done?

---

Use the addAttachmentData method of MFMailComposeViewController?