What I imagine a Cocoa-like Objective-C web framework woud look like. Pseudocode, so don't take it too seriously.

MyRootController.m

@interface MyRootController: OWWebController

// GET /
- (BOOL)get:(OWRequest*)request error:(NSError**)error {
	return [request.responder renderTemplate:@"Root" withObject:nil error:error];
}

// Everything under /users is handled by MyUsersController
- (OWWebController*)controllerForUsersRequest:(OWRequest*)request error:(NSError**)error {
	return [[MyUsersController alloc] initWithManagedObjectContext:self.managedObjectContext];
}

// Stuff inherited:
- (BOOL)request:(OWRequest*)request error:(NSError**)error;
- (OWController*)controllerForRequest:(OWRequest*)request error:(NSError**)error;
- (NSURL*)URLForComponents:(NSArray*)components andParameters:(NSDictionary*)params;	// And, for instance, -URLForUsersAndParameters:, etc.

@end

MyUsersController.m

@interface MyUsersController: OWRestfulWebController

- (NSString*)entityName {
	return @"User";
}

// Maybe there would be predicateForObjectsWith: and sortDescriptors in the parent class, and you could override those?
- (NSFetchRequest*)fetchRequestForObjectsWith:(NSString*)username forRequest:(OWRequest*)request error:(NSError**)error {
	NSFetchRequest * fetchReq = [super fetchRequestForObjectsWith:username forRequest:request error:error];
	if(username) {
		fetchReq.predicate = [NSPredicate predicateWithFormat:@"username = %@", username];
	}
	else {
		fetchReq.sortDescriptors = @[ [NSSortDescriptor sortDescriptorForKey:@"username" ascending:YES] ];
	}
	return YES;
}

// Ensures only you can edit your own account.
// There are also methods like -canPut:with:error: if there's only one action to worry about.
- (BOOL)canPerformAction:(SEL)action forRequest:(OWRequest*)request withComponents:(NSArray*)components error:(NSError**)error {
	if(![super canPerformAction:action forRequest:request withComponents:components error:error]) {
		return NO;
	}
	if(action == @selector(put:with:error:) || action == @selector(delete:with:error:) || action == @selector(get:with:editWithError:) || action == @selector(post:with:followWith:error:)) {
		User * accessingUser = [self objectWith:components.firstObject forRequest:request error:error];
		User * authenticatingUser = [self objectWith:request.session[@"authenticatedUser"] forRequest:request error:error];
		// Should sessions be structured somehow? Or should we expect people to declare appropriate categories on OWSession/OWWebController?
		
    		if(authenticatingUser != accessingUser && !authenticatingUser.administrator) {
    			*error = [NSError errorWithDomain:OWErrorDomain code:OWErrorUnauthorized userInfo:@{ NSLocalizedDescriptionKey: NSLocalizedString(@"You are not authorized to access this user's data.", @"") }];
    			return NO;
		}
	}
	return YES;
}

// These actions are all implemented by OWRestfulWebController, so we get them for free:
// GET .
- (BOOL)get:(OWRequest*)request error:(NSError**)error;
// POST .
- (BOOL)post:(OWRequest*)request error:(NSError**)error;
// GET ./new
- (BOOL)get:(OWRequest*)request newWithError:(NSError**)error;
// GET ./$username
- (BOOL)get:(OWRequest*)request with:(NSString*)component error:(NSError**)error;
// PUT ./$username 
- (BOOL)put:(OWRequest*)request with:(NSString*)component error:(NSError**)error;
// DELETE ./$username
- (BOOL)delete:(OWRequest*)request with:(NSString*)component error:(NSError**)error;
// GET ./$username/edit
- (BOOL)get:(OWRequest*)request with:(NSString*)component editWithError:(NSError**)error;

// Everything under ./$username/posts is handled by MyPostsController
- (OWWebController*)controllerWith:(NSString*)username postsWithRequest:(OWRequest*)request error:(NSError**)error {
    OWUser * user = [self objectWith:username forRequest:request error:error];
    
    // This would be a custom-implemented initializer
    return [[MyPostsController alloc] initWithUser:user];
}

// Here are some additional non-restful actions...

// GET ./suspended
- (BOOL)get:(OWRequest*)request suspendedWithError:(NSError**)error {
	NSFetchRequest * fetchReq = [self fetchRequestForObjectsWith:nil forRequest:request error:error];
	if(!fetchReq) {
		return nil;
	}
	fetchReq.predicate = [NSCompoundPredicate andPredicateWithSubpredicates:[NSArray arrayWithObjects:[NSPredicate predicateWithFormat:@"suspended == YES"], fetchReq.predicate, nil]];
	
	NSArray * users = [self.managedObjectContext executeFetchRequest:fetchReq error:error];
	if(!users) {
		return NO;
	}
	
	return [request.responder renderTemplate:@"MyUsersController/suspended" withObject:users error:error];
}

// POST ./$foo/follow/$bar
- (BOOL)post:(OWRequest*)request with:(NSString*)username followWith:(NSString*)otherUsername error:(NSError**)error {
	OWAccount * me = [self objectWith:username forRequest:request error:error];
	OWAccount * other = [self objectWith:otherUsername forRequest:request error:error];
	
	if(!me || !other) {
		return NO;
	}
	
	[me addFollowing:other];
	if(![self.managedObjectContext save:error]) {
		return NO;
	}
	
	return [request.responder redirectTo:[OWApplication.sharedApplication.rootWebController URLForUsersWith:otherUsername andParameters:nil]];
}

// DELETE ./$foo/follow/$bar
- (BOOL)delete:(OWRequest*)request with:(NSString*)username followWith:(NSString*)otherUsername error:(NSError**)error {
	OWUser * me = [self objectWith:username forRequest:request error:error];
	OSUser * other = [self objectWith:otherUsername forRequest:request error:error];
	
	if(!me || !other) {
		return NO;
	}
	
	[me removeFollowing:other];
	if(![self.managedObjectContext save:error]) {
		return NO;
	}
	
	return [request.responder redirectTo:[OWApplication.sharedApplication.rootWebController URLForUsersWith:otherUsername andParameters:nil]];
}

// Stuff inherited:
- (NSArray*)objectsWith:(NSString*)username forRequest:(OWRequest*)request error:(NSError**)error;
- (NSManagedObject*)objectWith:(NSString*)username forRequest:(OWRequest*)request error:(NSError**)error;	// Requires exactly one, errors otherwise
- (NSManagedObject*)newObjectForRequest:(OWRequest*)request error:(NSError**)error;

@end