Need to add a NSDistributedNotification observer in my Firebreath project

问题

I need to send a distributed notification from my cocoa app to my firebreath project, so I need to create an observer and a selector in my firebreath code. I changed the class extension to ".mm" in order to support objective-c code. I already have objective-c code in my firebreath project and is working ok. But when I try to create an observer I get errors in my code and I don't know how to resolve it.

Here is my source code from firebreath project:

//This is the selector 
- (void)receiveAppConfirmationNotification:(NSNotification*)notif{
    //The application is alive.
    NSLog(@"The application is alive!!!!!!!!");
}

std::string MyProjectAPI::bgp(const std::string& val)
{       
    //Add an observer to see if the application is alive.
    NSString *observedObject = @"com.test.net";
    NSDistributedNotificationCenter *center = [NSDistributedNotificationCenter defaultCenter];
    [center addObserver: self
               selector: @selector(receiveAppConfirmationNotification:)
                   name: @"App Confirmation Notification"
                 object: observedObject];
}

Here are my errors:

...firebreath/../projects/MyProject/MyProjectAPI.mm:133: error: expected unqualified-id before '-' token. This is the line where I defined the "receiveAppConfirmationNotification" method.

...firebreath/../projects/MyProject/MyProjectAPI.mm:157: error: 'self' was not declared in this scope.

How can I do to define the selector? How can I do to add the observer as the class itself?

回答1:

A selector has to be part of an objective-c++ class; you can't just throw it in the middle of nowhere there, it should be in the @implementation section of the class.

To keep things as compatible as possible, I recommend putting both @interface and @implementation sections in the .mm file so that the .h file is compatible with C++, but that's up to you; it'll just be easier if you do it that way. You can use the pimpl pattern to help with this if you want.

回答2:

I did the interface and the implementation and the code is without errors. The problem is that I am able to send notifications to my cocoa application, but I am not able to recibe a notification from the application to the plugin. Here is header file:

#ifdef __OBJC__

@interface FBMyProject : NSObject {
    NSString *parameter_val;
}

@property (nonatomic, retain) NSString *parameter_val;

-(void) receiveAppConfirmationNotification:(NSNotification*)notif;

@end
#endif

class MyProjectAPI : public FB::JSAPIAuto
{
    public:
    ...
}
#endif

Here is my source file:

@implementation FBMyProject
@synthesize parameter_val;

  -(void) receiveAppConfirmationNotification:(NSNotification*)notif{
       //The application is alive.
       NSLog(@"The application is alive!!!!!!!!");
   }

  - (id)init
  {
      self = [super init];
      if (self) {
          NSString *observedObject = @"test.com";
          NSDistributedNotificationCenter *center = [NSDistributedNotificationCenter defaultCenter];
          [center addObserver: self
                     selector: @selector(receiveAppConfirmationNotification:)
                         name: @"App Confirmation Notification"
                       object: observedObject];

      }
      return self;
  }

  - (void)dealloc
  {
      // unregister notification
      [[NSDistributedNotificationCenter defaultCenter] removeObserver: self 
                                                                 name: @"App Confirmation Notification"
                                                               object: nil];

      [self.parameter_val release];
      [super dealloc];
  }
@end



std::string MyProjectAPI::bgp(const std::string& val)
{       
    FBMyProject *my_project = [[FBMyProject alloc] init];
    my_project.parameter_val = [NSString stringWithUTF8String:val.c_str()];
    [my_project release];

    return val;
}

Here is my source from the cocoa application:

NSDictionary *data = [NSDictionary dictionaryWithObjectsAndKeys:
                      @"OK", @"confirmation", 
                      nil];

//Post the notification
NSString *observedObject = @"test.com";
NSDistributedNotificationCenter *center = [NSDistributedNotificationCenter defaultCenter];
[center postNotificationName: @"App Confirmation Notification"
                      object: observedObject
                    userInfo: data
          deliverImmediately: YES];

来源：https://stackoverflow.com/questions/8680145/need-to-add-a-nsdistributednotification-observer-in-my-firebreath-project

标签

objective-c

firebreath