Automapper: Mapping objects Part 6 of 7 (CustomFormatter)

In this part I will show how we can use a customer value formatter (CustomFormatter) to format our mapped data into single “Number of Order:” and plural “Number of Orders:”.

First the Domain and Dto (data transfer object)

//Domain
public class Order
    {
        public string OrderNo { get; set; }
        public Customer Customer { get; set;  }
        public DateTime PurchaseDate { get; set; }
        public IEnumerable LineItems { get; set; }
        public bool ShipToHomeAddress { get; set; }
        public decimal GetTotal()
        {
            return LineItems == null ? 0 : LineItems.Sum(x => x.GetTotalPrice());
        }
        public Guid InternalId { get; set; }
    }

//Dto
public class NumberOfOrderDto
    {
        public string CustomerName { get; set; }
        public string NumberOfOrders { get; set; }
    }

Now we will introduce a CustomResolver and Formatter, for the Formatter we are inheriting from IValueFormatter

//Resolver
public class CustomOrderCount: ValueResolver
    {
        protected override int ResolveCore(Order source)
        {
            return source.LineItems.Count();
        }
    }

//Formatter
public class FormatOrderCount: IValueFormatter
    {
        public string FormatValue(ResolutionContext context)
        {
            int num = (int)context.SourceValue;

            if (num 
For our mapping code we will use a block for options, so that after resolving the value, it would format it.
public ActionResult NumberOfOrders()
        {
            var orders = _respository.GetAll();

            orders.First().LineItems = new List();

            Mapper.CreateMap()
                .ForMember(dest => dest.NumberOfOrders, opt =>
                                                            {
                                                                opt.ResolveUsing();
                                                                opt.AddFormatter();
                                                            });

            var model = Mapper.Map, IEnumerable>(orders);

            return View(model);
        }

//View
NumberOfOrders

@foreach (var order in Model)
{
    

    @order.CustomerName 

    @order.NumberOfOrders 

    
}

From the view we can see that the first order is displaying Order rather than Orders.


In the last part of the series I will show how to move all your mapping code to startup, so that it would speed things up.
Previous Post

Part 1 (NullSubsitution)

Part 2 (Flattening by Convention)

Part 3 (Nested Mapping)

Part 4 (Projection)

Part 5 (CustomResolver)


Related posts:

Automapper: Mapping objects Part 5 of 7 (CustomResolver)
Automapper: Mapping objects Part 4 of 7 (Projection)
Automapper: Mapping objects Part 3 of 7 (Nested Mapping)
Automapper: Mapping objects Part 1 of 7 (NullSubstitution)