MFMailComposeViewController in a separate class - iphone

Question

I seek to create a "Utility Email sender class" that I can use in several iPhone projects.
I created MailSender header and implementation for that purpose.
MailSender.h:
#interface MailSender : NSObject<MFMailComposeViewControllerDelegate>
- (id) initWithParent:(UIViewController*) mainController;
- (void) invokeMailSender:(NSString*) to:(NSString*) subject:(NSString*) failureTitle:(NSString*) failureMessage:(NSString*) failureCancel;
#end
MailSender.m:
#import "MailSender.h"
#implementation MailSender
MFMailComposeViewController* mailer;
UIViewController* mailParentController;
- (id) initWithParent:(UIViewController*) mainController
{
if( self = [super init])
{
mailParentController = mainController;
}
return self;
}
- (void) invokeMailSender:(NSString*) to:(NSString*) subject:(NSString*) failureTitle:(NSString*) failureMessage:(NSString*) failureCancel;
{
if([MFMailComposeViewController canSendMail])
{
mailer = [[MFMailComposeViewController alloc] init];
mailer.mailComposeDelegate = self;
[mailer setSubject:subject];
NSArray *toRecipients = [NSArray arrayWithObjects:to, nil];
[mailer setToRecipients:toRecipients];
[mailParentController presentModalViewController:mailer animated:YES];
}
else
{
UIAlertView* alert = [[UIAlertView alloc] initWithTitle:failureTitle message:failureMessage
delegate:nil cancelButtonTitle:failureCancel otherButtonTitles: nil];
[alert show];
}
}
-(void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error
{
// Do nothing
[mailParentController dismissModalViewControllerAnimated:YES];
mailer = nil;
}
#end
I called the class from a View Controller (in a button touch down action) using the following instructions:
#implementation InfoViewController
MailSender *sender;
- (IBAction)openMail:(id)sender
{
sender = [[MailSender alloc] initWithParent:self];
[sender invokeMailSender:#"test#test.com" :#"123" :#"123" :#"123" :#"123"];
}
....
#end
When I run the code, I am able to show the email views correctly. However, this is then followed by a crash.
Note that I do not have a crash when using MFMailComposeViewController directly from my UIViewController (And assigning the View Controller as the delegate),
Any ideas?
Sorry I am still a new to Objective C :)

Answer 1

You need to retain your sender MailSender instance. It is being released after you call the invoke message.
You could do this by declaring a property named sender. E.g.
#property (strong, nonatomic) MailSender *sender;
...
#synthesize sender = _sender;
...
self.sender = [[MailSender alloc] initWithParent:self];
[self.sender invokeMailSender:#"noor#dimachk.com" :#"123" :#"123" :#"123" :#"123"];
By the way, your method declaration is a bit funny. You should name the arguments. E.g.
- (void)invokeMailSender:(NSString *)sender
to:(NSString *)to
subject:(NSString *)subject
failureTitle:(NSString *)failureTitle
failureMessage:(NSString *)failureMessage
failureCancelButtonTitle:(NSString *)failureCancelButtonTitle