Question

I have a Cocoa application (.app) and I would like to launch it from another Cocoa application, no problem here, but is there any way to launch the second application passing it some parameters ? maybe using the argv[] array in the main function?

Answer 1

I did this using NSWorkspace to launch the app, and NSDistributedNotificationCenter to pass the data. This obviously isn’t fully developed, but it worked. One caveat from the docs — the dictionary I sent with the argument (just a string in this example) can’t be used in a sandboxed app (the dictionary must be nil).

This is in the app that opens the other app:

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification 
{
ws = [NSWorkspace sharedWorkspace];
NSNotificationCenter *center = [ws notificationCenter];
[center addObserver:self selector:@selector(poster:) name:NSWorkspaceDidLaunchApplicationNotification object:nil];
[ws launchApplication:@"OtherApp.app"];
}

-(void)poster:(NSNotification *) aNote 
 {
NSDistributedNotificationCenter *center = [NSDistributedNotificationCenter defaultCenter];
NSDictionary *dict = [NSDictionary dictionaryWithObject:@"theDataToSend" forKey:@"startup"];
[center postNotificationName:@"launchWithData" object:nil userInfo:dict];
NSLog(@"Posted notification");
 }

And this is in the app that is opened:

-(void)awakeFromNib 
{
NSDistributedNotificationCenter *center = [NSDistributedNotificationCenter defaultCenter];
[center addObserver:self selector:@selector(doStartup:) name:@"launchWithData" object:nil];
}

 -(void)doStartup:(NSNotification *) aNote 
    {
    NSLog(@"%@",aNote.userInfo);
    }