Pattern for Product to Product Variant association

Is there a design pattern to solve the product to product variant association? A product varies from another product by only it's color, size or material only. Every other static properties like name and description are the same.

I looked at the type-object / item-descriptor pattern which does not seem to be a fit. In this case, I'm not creating two types of products but the same type of product but varies in dynamic properties. I don't know these properties (color, size and material) at compile time. I know what they are at run time only.

Any idea?

Varghese Pallathu, Apr 16, 2012

Reply 1

I've a simple pattern I like to use in cases such as these. I call it the comparator pattern. Here's a simple Console app that can be used to describe a possible solution.

I hope this helps

class Program
    {
        static void Main(string[] args)
        {
            var productA = new Product("Red", "Shoes", "10", "Rubber");
            var productB = new Product("Red", "Shoes", "10", "Rubber");
            var productC = new Product("Green", "Shoes", "8", "Plastic");

            if (productA.IsEqualTo(productB)){Console.WriteLine("Product A and Product B are the same");}
            if (!productB.IsEqualTo(productC)){Console.WriteLine("Product B and Product C are NOT the same"); }

            Console.ReadLine();
        }

        
    }

    public class Product
    {
        private readonly string color, name, size, material;

        public Product(string color, string name, string size, string material)
        {
            this.color = color;
            this.name = name;
            this.size = size;
            this.material = material;
        }

        public bool IsEqualTo(Product product)
        {       
            return (product.color == color && product.name == name) && product.material == material;
        }
    }

Sameer Lamba, Apr 18, 2012

Thats a good point and one possible answer. I think thats why singleton class can be used for state mangement in stateless scenarios like shopping cart scenario,

Apr 17, 2012