Plugin iOS to send Mail with MFMailComposeViewController

Hello everyone,

First excuse me for my bad english. I would like to create a plugin for iOS that allows you to send an email with an attachment. For this, I create a static library in a MailPlugin class. Here is the header and .m file.

 #import <Foundation/Foundation.h>
 #import <MessageUI/MFMailComposeViewController.h>
 
 @interface MailPlugin : UIViewController <MFMailComposeViewControllerDelegate>{
     UIViewController *viewController;
 }
  
 -(id)init:(UIViewController*)viewControllerValue;
 
 -(void)sendMailWithAttachment:(NSString*)subject Body:(NSString *)body Attachment:(NSString *)attachment;
 
 -(void) mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error;
 
 @end

 #import "MailPlugin.h"
 
 @implementation MailPlugin
 
 -(id)init:(UIViewController*)viewControllerValue {
     self = [super init];
     if (self){
         viewController = viewControllerValue;
     }
     NSLog(@"Init viewController: %@",viewController);
     return self;
 }
 
 
 -(void)sendMailWithAttachment:(NSString*)subject Body:(NSString *)body Attachment:(NSString *)attachment{
     if ([MFMailComposeViewController canSendMail]) {
         MFMailComposeViewController *mailController = [[MFMailComposeViewController alloc] init];
         mailController.mailComposeDelegate = self;
         // Create data to attach
 //        NSData *data = [[NSFileManager defaultManager] contentsAtPath:attachment];
         // Create the file name
 //        NSString *name = [attachment substringFromIndex:[attachment rangeOfString:@"/" options:NSBackwardsSearch].location + 1];
         // Add informations to mail controller
         [mailController setSubject:subject];
         [mailController setMessageBody:body isHTML:false];
 //        [mailController addAttachmentData:data mimeType:@"message/rfc822" fileName:name];
         NSLog(@"Fin preparation mail");
         [viewController presentViewController:mailController animated:YES completion:NULL];
         NSLog(@"Affichage mail");
     }
     else {
         NSLog(@"Device is unable to send email");
     }
 }
 
 
 -(void) mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error{
     switch (result) {
         case MFMailComposeResultCancelled:
             NSLog(@"Mail cancelled");
             break;
         case MFMailComposeResultSaved:
             NSLog(@"Mail saved");
             break;
         case MFMailComposeResultSent:
             NSLog(@"Mail sent");
             break;
         case MFMailComposeResultFailed:
             NSLog(@"Mail failed");
             break;
         default:
             break;
     }
     [viewController dismissViewControllerAnimated:YES completion:NULL];
 }
 
 
 @end
 

For momenent I commented the part to manage the attachment function sendMailWithAttachment. I then use a wrapper on the Assets/Plugins/iOS folder, here .h and .mm.

 #import "ClipboardPlugin.h"
 #import "PhotosPlugin.h"
 #import "ToastPlugin.h"
 #import "MailPlugin.h"
 
 extern "C" void copyStringIntoClipboard_Helper(char *text);
 
 extern "C" void downloadImageInPhotos_Helper(char *filePath);
 
 extern "C" void displayTextToast_Helper(char *text, double duration);
 
 extern "C" void sendMailWithAttachment_Helper(char *subject, char *body, char *attachment);

 #import "PluginsiOSWrapper.h"
 
 extern UIView *UnityGetGLView();
 extern UIViewController *UnityGetGLViewController();
 
 void copyStringIntoClipboard_Helper(char *text){
     [ClipboardPlugin copyStringIntoClipboard:[NSString stringWithUTF8String:text]];
 }
 
 void downloadImageInPhotos_Helper(char *filePath){
     [PhotosPlugin downloadImageInPhotos:[NSString stringWithUTF8String:filePath]];
 }
 
 void displayTextToast_Helper(char *text, double duration){
     [ToastPlugin displayTextToast:[NSString stringWithUTF8String:text] View:UnityGetGLView() Duration:duration];
 }
 
 static MailPlugin *mp = NULL;
 
 void sendMailWithAttachment_Helper(char *subject, char *body, char *attachment){
     if (mp==NULL){
         mp = [[MailPlugin alloc] init:UnityGetGLViewController()];
     }
     [mp sendMailWithAttachment:[NSString stringWithUTF8String:subject] Body:[NSString stringWithUTF8String:body] Attachment:[NSString stringWithUTF8String:attachment]];
 }

When I launch my application and I press the button to call the method sendMailWithAttachment_Helper PluginiOSWrapper.mm file, the email view appears fine but I can't do anything without crash with a message "Terminate due to memory pressure ". Here logs Xcode when I clicked on the button:

 2014-05-21 16:44:01.641 Prototype[11126:60b] Init viewController: <UnityDefaultViewController: 0x156851a0>
 2014-05-21 16:44:02.227 Prototype[11126:60b] Fin preparation mail
 2014-05-21 16:44:02.482 Prototype[11126:60b] Affichage mail
 2014-05-21 16:44:19.627 Prototype[11126:60b] Received memory warning.
 WARNING -> applicationDidReceiveMemoryWarning()
 2014-05-21 16:44:20.270 Prototype[11126:60b] Received memory warning.
 WARNING -> applicationDidReceiveMemoryWarning()
 2014-05-21 16:44:20.402 Prototype[11126:60b] Received memory warning.
 WARNING -> applicationDidReceiveMemoryWarning()
 2014-05-21 16:44:37.280 Prototype[11126:60b] Received memory warning.
 WARNING -> applicationDidReceiveMemoryWarning()
 2014-05-21 16:44:37.697 Prototype[11126:60b] Received memory warning.
 WARNING -> applicationDidReceiveMemoryWarning()

I can not find the problem, would anyone have a solution? Thank you in advance Noémie