@Override
	synchronized public Boolean handleInput(String input) {
		if(input.equals("quit")) {
			return false;
		} else if(input.equals("exit")) {
			currentReceipt.setDate(new Date());
			notifyTotal();
			currentReceipt = new Receipt();
		} else if(input.equals("")) {
			notifyError("Invalid bar-code.");
		} else {
			Product product = productService.getProduct(input);
			if(product != null) {
				currentReceipt.addProduct(product);
				notifySingle(product);
			} else {
				notifyError("Product not found.");
			}
		}
		return true;
	}