initWithTarget:selector:objects: (multiple objects, until nil) cathegory for NSInvocationOperation

NSInvocationOperation+multipleObject.m

@interface NSInvocationOperation (mutipleObject)
- (id)initWithTarget:(id)target selector:(SEL) objects:(id)first, ...;
@end

@implementation NSInvocationOperation (multipleObjects)

- (id)initWithTarget:(id)target selector:(SEL)sel objects:(id)first, ... {
	NSAutoreleasePool *pool = [NSAutoreleasePool new];
	
	NSMethodSignature *signature = [target methodSignatureForSelector:sel];
	NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:signature];
	[invocation setTarget:target];
	[invocation setSelector:sel];
	
	va_list args;
	va_start(args, first);
	NSUInteger i = 2;
	id obj = nil;
	for (obj = first; obj != nil; obj = va_arg(args, id)) {
		[invocation setArgument:&obj atIndex:i];
		++i;
	}
	va_end(args);
	
	[invocation retainArguments];
	[self initWithInvocation:invocation];
	[pool release];
	
	return self;
}

@end