static void Main(string[] args)
{
var apple = new Product("Apple", Colour.Green, Size.Small);
var tree = new Product("Tree", Colour.Green, Size.Large);
var house = new Product("House", Colour.Blue, Size.Large);
Product[] products = { apple, tree, house };
WriteLine("Large products (old method):");
var pf = new ProductFilter();
foreach (var p in pf.FilterBySize(products, Size.Large))
{
WriteLine($" - {p.Name} is large");
}
WriteLine("Large products (new method):");
var bf = new BetterFilter();
foreach (var p in bf.Filter(products, new SizeSpecification(Size.Large)))
{
WriteLine($" - {p.Name} is large");
}
// See how easy to add a new filter of colour.
// The filter stays the same, add a new specification.
// Open to extenstion by add a new specification,
// close to modification to filter and specification.
WriteLine("Green products (old method):");
foreach (var p in pf.FilterByColour(products, Colour.Green))
{
WriteLine($" - {p.Name} is green");
}
WriteLine("Green products (new method):");
foreach (var p in bf.Filter(products, new ColourSpecification(Colour.Green)))
{
WriteLine($" - {p.Name} is green");
}
// Add combination filter
WriteLine("Large blue item:");
foreach (var p in bf.Filter(products, new AndSpecification(
new ColourSpecification(Colour.Blue),
new SizeSpecification(Size.Large))))
{
WriteLine($" - {p.Name} is big and blue");
}
}
static void Main(string[] args)
{
var apple = new Product("Apple", Color.Green, Size.Small);
var tree = new Product("Tree", Color.Green, Size.Large);
var house = new Product("House", Color.Blue, Size.Large);
Product[] products = { apple, tree, house };
var bf = new BetterFilter();
WriteLine("Green Products: ");
foreach (var product in bf.Filter(products, new ColorSpeficiation(Color.Green)))
{
WriteLine($"- {product.Name} is Green");
}
WriteLine("Large Products: ");
foreach (var product in bf.Filter(products, new IAndSpecification <Product>(new ColorSpeficiation(Color.Blue), new SizeSpeficiation(Size.Large))))
{
WriteLine($"- {product.Name} is Blue and Big");
}
ReadLine();
}