Automapper: Mapping objects Part 4 of 7 (Projection)

Taswar Bhatti March 10, 2011 4 Comments

In Part 4 we will see how we can use projection to map inner objects for example a DateTime field. Again our domain and Dto (Data Transfer Object) looks like

//Order
 public class Order
 {
        public string OrderNo { get; set; }
        public Customer Customer { get; set;  }
        public DateTime PurchaseDate { get; set; }
        public IEnumerable<OrderItems> 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 OrderDateDto
 {        
        public int PurchaseHour { get; set; }
        public int PurchaseMinute { get; set; }
        public string CustomerName { get; set; }     
 }

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//Order

public class Order

{

public string OrderNo { get; set; }

public Customer Customer { get; set; }

public DateTime PurchaseDate { get; set; }

public IEnumerable<OrderItems> 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 OrderDateDto

{

public int PurchaseHour { get; set; }

public int PurchaseMinute { get; set; }

public string CustomerName { get; set; }

}

We will map the PurchaseDate in the Domain Object to our Dto PurchaseHour and Purchase Minute.

 public ActionResult OrderDate()
 {
            var order = _respository.Get(3);

            order.PurchaseDate = new DateTime(2011, 3, 15, 20, 30, 0);
            Mapper.CreateMap<Order, OrderDateDto>()
             .ForMember(dest => dest.PurchaseHour, opt => opt.MapFrom(src => src.PurchaseDate.Hour))
             .ForMember(dest => dest.PurchaseMinute, opt => opt.MapFrom(src => src.PurchaseDate.Minute));
            
            var model = Mapper.Map<Order, OrderDateDto>(order);                

            return View(model);
}
//View
<h2>OrderDate</h2>

@Model.CustomerName @Model.PurchaseHour @Model.PurchaseMinute

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public ActionResult OrderDate()

{

var order = _respository.Get(3);

order.PurchaseDate = new DateTime(2011, 3, 15, 20, 30, 0);

Mapper.CreateMap<Order, OrderDateDto>()

.ForMember(dest => dest.PurchaseHour, opt => opt.MapFrom(src => src.PurchaseDate.Hour))

.ForMember(dest => dest.PurchaseMinute, opt => opt.MapFrom(src => src.PurchaseDate.Minute));

var model = Mapper.Map<Order, OrderDateDto>(order);

return View(model);

}

//View

<h2>OrderDate</h2>

@Model.CustomerName @Model.PurchaseHour @Model.PurchaseMinute

As you can see the View now […]

.NET, Automapper

automapper, C#, object mapping

Automapper: Mapping objects Part 3 of 7 (Nested Mapping)

Taswar Bhatti March 9, 2011 11 Comments

In this part we learn about Nested Mapping in Automapper and we will use the same OrderDto Object that we had previously but we will let Automapper to map the inner objects. Once again here is the Domain Objects First

//Order 
public class Order
    {
        public string OrderNo { get; set; }
        public Customer Customer { get; set;  }
        public DateTime PurchaseDate { get; set; }
        public IEnumerable<OrderItems> 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; }
    }

//OrderItems
public class OrderItems
    {
        public decimal Price { get; set; }
        public string Name { get; set; }
        public int Quantity { get; set; }
        public decimal GetTotalPrice()
        {
            return Price * Quantity;
        }
    }

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//Order

public class Order

{

public string OrderNo { get; set; }

public Customer Customer { get; set; }

public DateTime PurchaseDate { get; set; }

public IEnumerable<OrderItems> 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; }

}

//OrderItems

public class OrderItems

{

public decimal Price { get; set; }

public string Name { get; set; }

public int Quantity { get; set; }

public decimal GetTotalPrice()

{

return Price * Quantity;

}

The Dto (Data Transfer Object) look like

public class OrderDto
    {
        public string CustomerName { get; set; }
        public decimal Total { get; set; }
        public string OrderNumber { get; set; }
        public IEnumerable<OrderItemsDto> LineItems { get; set; }
    }

//OrderItemsDto
public class OrderItemsDto
    {
        public string Name { get; set; }
        public int Quantity { get; set; }
        public decimal Price { get; set; }
    }

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public class OrderDto

{

public string CustomerName { get; set; }

public decimal Total { get; set; }

public string OrderNumber { get; set; }

public IEnumerable<OrderItemsDto> LineItems { get; set; }

}

//OrderItemsDto

public class OrderItemsDto

{

public string Name { get; set; }

public int Quantity { get; set; }

public decimal Price { get; set; }

}

This time when we map Order […]

.NET, Automapper

automapper, C#, object mapping

Automapper: Mapping objects Part 2 of 7 (Flattening by Convention)

Taswar Bhatti March 8, 2011 2 Comments

In this part I will be showing how Automapper uses flattening by convention. If we look at our OrderDto we will see that it has a IEnumerable of OrderItemsDto and also something called OrderNumber. This is the type of object we want to send to our presentation layer.

 public class OrderDto
    {
        public string CustomerName { get; set; }
        public decimal Total { get; set; }
        public string OrderNumber { get; set; }
        public IEnumerable<OrderItemsDto> LineItems { get; set; }
    }

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public class OrderDto

{

public string CustomerName { get; set; }

public decimal Total { get; set; }

public string OrderNumber { get; set; }

public IEnumerable<OrderItemsDto> LineItems { get; set; }

}

Compare that to our domain object […]

.NET, Automapper

automapper, C#, object mapping

Automapper: Mapping objects Part 1 of 7 (NullSubstitution)

Taswar Bhatti March 7, 2011 2 Comments

Recently I gave a talk on Automapper in Ottawa .Net Community, so I though I would post the main ideas of the presentation here also. The demo was based on an Order System where there were just 3 tables/classes, “Order”, “Customer” and “OrderItems” From the diagram we can see that a Customer has a Bio […]

.NET, Automapper

automapper, C#, object mapping

Operator ‘==’ cannot be applied to operands of type ‘System.Collections.Generic.KeyValuePair‘ and ‘‘

Taswar Bhatti November 29, 2010 No Comments

You are here beacause you probably got a Linq error, specifically Operator ‘==’ cannot be applied to operands of type ‘System.Collections.Generic.KeyValuePair‘ and ‘‘ So if you wish to do something like this to KeyValuePair using Linq

var item = myDictionary.FirstOrDefault(x => x.Key == 123);
if(item != null)
{
 //blah blah

}

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var item = myDictionary.FirstOrDefault(x => x.Key == 123);

if(item != null)

{

//blah blah

}

You will get this error Operator ‘!=’ cannot be applied to operands of type ‘System.Collections.Generic.KeyValuePair‘ and ‘‘ Since […]

.NET, Misc

C#, generics, programming

Linq Sequence contains no matching element

Taswar Bhatti March 26, 2010 6 Comments

So sometimes you will get these strange errors or exceptions when using Linq Sequence contains no matching element For example if you use

var result = myEnumerableCollection.First(x => x.Name == person.Name);

1	var result = myEnumerableCollection.First(x => x.Name == person.Name);

This will throw InvalidOperationException with Sequence contains no matching element. But if you use

var result = myEnumerableCollection.FirstOrDefault(x => x.Name == person.Name);
if(result == null)
 //did not find in the collection something went wrong or .....

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var result = myEnumerableCollection.FirstOrDefault(x => x.Name == person.Name);

if(result == null)

//did not find in the collection something went wrong or .....

Which will return you a null if its not found then you can check if the […]

.NET, Misc

.net, FirstOrDefault, LINQ

Asp .NET Redirect To SSL HttpModule

Taswar Bhatti February 18, 2010 4 Comments

There are tones of blog post out there on how to redirect http to https. As in when a user request for http://myserver.com/Login.aspx they will be redirected to https://myserver.com/Login.aspx One can do it with IIS but I find that way a bit ugly since you have to create another site and set the 403 to […]

.NET, ASP .NET

ASP .NET, C#, https, redirect asp .net

Be mindful of the Null Pattern

Taswar Bhatti August 17, 2009 No Comments

Null Pattern Last time I blogged about “Learn the Null Pattern“, but I forgot to mention one thing about the Null Pattern. That is you have to be mindful of it. For example

foreach(var id in IDList)
{
        var employee = db.GetEmployee(id);
	salary = db.CalculateSalary(id);
	employee.Pay(salary);
}

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foreach(var id in IDList)

{

var employee = db.GetEmployee(id);

salary = db.CalculateSalary(id);

employee.Pay(salary);

}

The code looks okay but what if the GetEmployee method actually returns a NullEmployee? Well that would still be okay, since […]

.NET, Design

Design Pattern, Null Pattern

Automapper: Mapping objects Part 4 of 7 (Projection)

Automapper: Mapping objects Part 3 of 7 (Nested Mapping)

Automapper: Mapping objects Part 2 of 7 (Flattening by Convention)

Automapper: Mapping objects Part 1 of 7 (NullSubstitution)

Operator ‘==’ cannot be applied to operands of type ‘System.Collections.Generic.KeyValuePair‘ and ‘‘

Linq Sequence contains no matching element

Asp .NET Redirect To SSL HttpModule

Be mindful of the Null Pattern

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