Programmatically control iPhone OS versions to enable functions for both OS 3.x and 4 - MFMessageComposeViewController problem

Question

In order to support iPhone OS 3.x and 4.0 I programmatically control MFMessageComposeViewController functionality like this (use it only if the OS version is 4.0 or above):

// if iPhone OS version >= 4.0
if (os_version_num >= 4) {
   MFMessageComposeViewController *controller = [[MFMessageComposeViewController alloc] init];
   if([MFMessageComposeViewController canSendText])
   {
      controller.body = text;
      controller.recipients = [NSArray arrayWithObjects: nil];
      controller.messageComposeDelegate = self;
      [self presentModalViewController:controller animated:YES];
      [controller release];
   }
}

But, when I try to run it on iPhone 3.1.3 device, I immediately get the following error (even before application gets loaded):

dyld: Symbol not found: _OBJC_CLASS_$_MFMessageComposeViewController
  Referenced from: /var/mobile/Applications/7232C474-FAD5-4E28-ABC5-8520F62300B0/TextMe.app/TextMe
  Expected in: /System/Library/Frameworks/MessageUI.framework/MessageUI

Data Formatters temporarily unavailable, will re-try after a 'continue'. (Not safe to call dlopen at this time.)

What am I doing wrong?

score 17 · Accepted Answer · answered Jul 02 '10 at 03:08

You need to make sure you're doing a few things:

In your target's build settings:

set Base SDK to iPhone Device 4.0
set iPhone OS Deployment Target to iPhone OS 3.1.3 (or lower)

In your target's general settings, under Linked Libraries, change the "Type" next to MessageUI.framework to Weak.

Don't import <MessageUI/MFMessageComposeViewController.h> or it will crash on launch in 3.x. Just import <MessageUI/MessageUI.h>

I don't know what os_version_num is, but here's the code I use to test for the availability of MFMessageComposeViewController:

Class smsClass = (NSClassFromString(@"MFMessageComposeViewController"));
if (smsClass != nil && [MFMessageComposeViewController canSendText]) {
   MFMessageComposeViewController *controller = [[MFMessageComposeViewController alloc] init];
   controller.body = text;
   controller.recipients = [NSArray arrayWithObjects: nil];
   controller.messageComposeDelegate = self;
   [self presentModalViewController:controller animated:YES];
   [controller release];                
}

The language has changed from "weak" to "optional" in Xcode 4. — ma11hew28, Jul 07 '11 at 20:59

score 2 · Answer 2 · answered Jul 02 '10 at 03:28

Class theClass = NSClassFromString(@"MFMessageComposeViewController");
MFMessageComposeViewController *controller = theClass ? [[theClass alloc] init] : nil;

You can use the type MFMessageComposeViewController as in:

MFMessageComposeViewController *controller;

But you cannot use the global object MFMessageComposeViewController as in:

[MFMessageComposeViewController alloc];

Instead use the class lookup so you are not dependent on the linker:

[NSClassFromString(@"MFMessageComposeViewController") alloc];

score 1 · Answer 3 · answered Mar 04 '11 at 10:20

1

In your target parameters, simply set messageUI.framework to type 'weak'

answered Mar 04 '11 at 10:20

Raphaël Pinto

653
8
20

thanks a lot. if you don't do this messageUI.framework to type 'weak' then any above answer will not worked for you. – priyanka Jan 25 '12 at 07:25

score 0 · Answer 4 · answered Dec 28 '10 at 11:09

If you import <MessageUI/MessageUI.h> and set weak reference to MessageUI framework, you can directly call:

   if ([MFMessageComposeViewController canSendText]) {
        controller.body = body;
        controller.recipients = [NSArray arrayWithObjects:number, nil];
        controller.messageComposeDelegate = self;
        [self presentModalViewController:controller animated:YES];
        [controller release]; 
    } else {
        [[UIApplication sharedApplication] openURL: [NSURL URLWithString:[NSString stringWithFormat:@"sms:%@",number]]];
    }

On iOS 3.1.2 you will get nil in the if clause and old method will be launched.

score 0 · Answer 5 · answered Jan 10 '11 at 23:53

0

I was having the same problem, and solved it a different way:

On the Left hand-side of your XCode window,

If you scroll down to the Bulls Eye with "Targets" and expand that
Expand your
< control > + < click > on "Link Binary With Libraries"
Choose "Add" --> "Existing Frameworks"
Choose "MessageUI.framework" and click on "Add"

That should add the Message UI to your app, tell me if it works.

answered Jan 10 '11 at 23:53

Khattab

737
1
10
20

In xcode 4, you can do just about the same thing by clicking on your project header in the File Browser, going to your target, and then going to the "Build Phases" tab. – Andrew Rueckert Feb 23 '12 at 23:18
Thanks Andrew, didn't know that, I'll check it out. – Khattab Feb 24 '12 at 20:41

score 0 · Answer 6 · edited Jan 16 '12 at 16:32

What about if you have functions that you only want to include conditionally.

- (void)messageComposeViewController:(MFMessageComposeViewController *)controller   
                 didFinishWithResult:(MessageComposeResult)result {
    [self dismissModalViewControllerAnimated:YES];
}

For example, if the function definition contained MFMessageViewController, how do you make this part conditional (that is, not cause a problem with OS 3.x). Or is it not a problem at all?

Programmatically control iPhone OS versions to enable functions for both OS 3.x and 4 - MFMessageComposeViewController problem

6 Answers6

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