using System;

using System.Linq;

using NUnit.Framework;

using SharpRepository.Repository;

using Shouldly;

using SharpRepository.InMemoryRepository;

namespace SharpRepository.Samples

{

[TestFixture]

public class HowToUseGetSelectors

{

/*

* What are Get Selectors?

*

* There are overloaded versions of the Get, GetAll, Find and FindAll methods

* that allow the use of a selector expression. You can think of it as what you

* would pass to the LINQ .Select() method.

*

* This allows you to only bring back the columns you are looking for to decrease

* network traffic, or map from your Entity to a ViewModel or other object structure

* that you need it in.

*

* What does this look like in practice?

*

* Let's try it out with some Orders and a OrderRepository

*/

public class Order

{

public int OrderId { get; set; }

public string Name { get; set; }

public double Total { get; set; }

public DateTime OrderDate { get; set; }

}

public class OrderViewModel

{

public string Name { get; set; }

public bool IsExpensiveOrder { get; set; }

}

[Test]

public void Repository_Supports_Selectors()

{

var repo = new InMemoryRepository<Order>();

// let's add a couple of orders to work with

repo.Add(new Order()

{

Name = "Order 1",

Total = 120.00,

OrderDate = new DateTime(2013, 4, 26)

});

repo.Add(new Order()

{

Name = "Order 2",

Total = 80.00,

OrderDate = new DateTime(2013, 4, 24)

});

// normal Get method

var order = repo.Get(1);

order.OrderId.ShouldBe(1);

// in this case we only need the order name

var orderName = repo.Get(1, x => x.Name);

orderName.ShouldBe("Order 1");

// we can also bring back an anonymous type if needed

var anonymousType = repo.Get(1, x => new { Name = x.Name, IsExpensiveOrder = x.Total > 100.0 });

anonymousType.IsExpensiveOrder.ShouldBeTrue();

// or we can map it to a specific type we have defined like a ViewModel

var viewModel = repo.Get(1, x => new OrderViewModel() {Name = x.Name, IsExpensiveOrder = x.Total > 100.0});

viewModel.IsExpensiveOrder.ShouldBeTrue();

// We have the same options with the GetAll, Find and FindAll as well

orderName = repo.Find(x => x.OrderId == 2, x => x.Name);

orderName.ShouldBe("Order 2");

// we can also bring back an anonymous type if needed

var anonymousTypes = repo.GetAll(x => new { Name = x.Name, IsExpensiveOrder = x.Total > 100.0 }).ToList();

anonymousTypes.Count.ShouldBe(2);

anonymousTypes.First().Name.ShouldBe("Order 1");

anonymousTypes.First().IsExpensiveOrder.ShouldBeTrue();

anonymousTypes.Last().Name.ShouldBe("Order 2");

anonymousTypes.Last().IsExpensiveOrder.ShouldBeFalse();

// or we can map it to a specific type we have defined like a ViewModel

var viewModels = repo.FindAll(x => x.OrderId < 5, x => new OrderViewModel() { Name = x.Name, IsExpensiveOrder = x.Total > 100.0 }).ToList();

viewModels.Count.ShouldBe(2);

viewModels.First().Name.ShouldBe("Order 1");

viewModels.First().IsExpensiveOrder.ShouldBeTrue();

viewModels.Last().Name.ShouldBe("Order 2");

viewModels.Last().IsExpensiveOrder.ShouldBeFalse();

}

}

}