I would like to create a file using a NSString (already made) with a .csv extension then email it using the UIMessage framework. So can someone show me the code to create a file (with a .csv extensions and with the contents of a NSString) then how to attach it to a MFMailComposeViewController.
This is how you attach a CSV file to a MFMailComposeViewController:
MFMailComposeViewController *mailer = [[MFMailComposeViewController alloc] init];
mailer.mailComposeDelegate = self;
[mailer setSubject:@"CSV File"];
[mailer addAttachmentData:[NSData dataWithContentsOfFile:@"PathToFile.csv"]
mimeType:@"text/csv"
fileName:@"FileName.csv"];
[self presentModalViewController:mailer animated:YES];
// Note: PathToFile.csv is the actual path of the file on your iOS device's
// file system. FileName.csv is what it should be displayed as in the email.
As far as how to generate the CSV file itself, the CHCSVWriter class at https://github.com/davedelong/CHCSVParser will help you.