Database Reference
In-Depth Information
This bit of C code determines whether the
address
received from the
NSSocketPort
is IPv4 or IPv6 and, based on that decision, extracts the port information from
the
address
and returns it to the caller.
With the port number in hand, we next construct an
NSConnection
and assign
the
AppDelegate
as the root object. The root object is what will be “proxied” to
any clients, and any methods they call on that proxy object will be transferred
to the root object on the receiver. In a more complex example, it would make
sense to have a separate object used as the proxy instead of the
AppDelegate
.
With the
NSConnection
created, we can initialize the
NSNetService
. The
NSNetService
handles the broadcasting using Bonjour. Bonjour requires four pieces of
information: the domain, type, name, and port. We discovered the port previ-
ously, and we defined the domain and type within the
PPDistributedProtocol
. The
last value is the name of server and should be unique per machine. With this
information, we can instantiate the
NSNetService
, set its delegate, and publish
it. Once we call
-publish
, other machines can see the service.
Starting the Server
The
-startBroadcasting
method is invoked from
-applicationDidFinishLaunching:
- (
void
)applicationDidFinishLaunching:(NSNotification*)notification
{
[self startBroadcasting];
saveTimer = [NSTimer scheduledTimerWithTimeInterval:(5.0 * 60.0)
target:self
selector:
@selector
(saveAction:)
userInfo:nil
repeats:YES];
}
In addition to broadcasting the service on start-up, we schedule an autosave
of the
NSManagedObjectContext
. In this example, we automatically save every five
minutes.
- (IBAction)saveAction:(id)sender
{
NSError *error = nil;
NSManagedObjectContext *context = [self managedObjectContext];
if
(![context hasChanges])
return
;
if
(![context save:&error]) {
[self logError:error];
}
}
