unable to load the mail client in iOS - objective-c

Question

I noticed that I am using the mail functionality several time so I decided to make an independent Class for functions that get repeated several time instead of copy-pasting the code several times
the class get successfully called and the e-mail function get successfully called as well but the e-mail client of the phone does not appear after the function is called
here is my code
in the main class I do the following call
-(void)emailFunction{
...
CommonlyUsed Email = [[CommonlyUsed alloc] init];
[Email sendMail:receipient :CC :BCC :subject :body];
...
}
in my CommonlyUsed.h I have the following IDEs called :
#import <UIKit/UIKit.h>
#import <MessageUI/MFMailComposeViewController.h>
#import <MessageUI/MessageUI.h>
#interface CommonlyUsed : UIViewController <MFMailComposeViewControllerDelegate>{
in CommonlyUsed.m I have the following :
-(void)sendMail:(NSString*)receipient:(NSString*)cc:(NSString*)bcc:(NSString*)subject:(NSString*)body{
MFMailComposeViewController *composer = [[MFMailComposeViewController alloc] init];
[ composer setMailComposeDelegate:self];
if ( [MFMailComposeViewController canSendMail]){
if (receipient) {
[composer setToRecipients:[NSArray arrayWithObjects:receipient, nil]];
}
if (cc) {
[composer setCcRecipients:[NSArray arrayWithObjects:receipient, nil]];
}
if (bcc) {
[composer setBccRecipients:[NSArray arrayWithObjects:receipient, nil]];
}
if (subject) {
[composer setSubject:subject];
}
[composer setMessageBody:body isHTML:HTMLBody];
[composer setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
[self presentModalViewController:composer animated:YES];
}
}
- (void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error {
if(error){
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"error" message:[NSString stringWithFormat:#"error %#", [error description]] delegate:nil cancelButtonTitle:#"dismiss" otherButtonTitles:nil, nil];
[alert show];
[self dismissModalViewControllerAnimated:YES];
}
else{
[self dismissModalViewControllerAnimated:YES];
}
}
the code compiles and runs without errors what am I missing ??

Answer 1

Instead of doing this:
[self presentModalViewController:composer animated:YES];
do this:
[[[[[UIApplication sharedApplication] delegate] window] rootViewController] presentModalViewController:composer animated:YES];
or this:
[[[[UIApplication sharedApplication] keyWindow] rootViewController] presentModalViewController:composer animated:YES];
Your class Email is not currently an active view controller so it can't present a modal view controller, you need to use an active one, like the rootViewController of the main UIWindow.
EDIT:
If your using ARC by the time the emailClient gets dismissed your object(delegate) would have been removed from memory, so a solution is to make the CommonlyUsed class a Singleton:
+(CommonlyUsed *)sharedInstance {
static CommonlyUsed * cu = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
cu = [[CommonlyUsed alloc] init];
});
return cu;
}
So you would use it this way:
CommonlyUsed * email = [CommonlyUsed sharedInstance];
[email sendMail:receipient :CC :BCC :subject :body];

Answer 2

You send presentModalViewController: to your instance Email of class CommonlyUsed, but this instance is not a view controller in the view hierarchy.
You must send presentModalViewController: to your currently active view controller.