How to map lists with ValueInjector - asp.net

Question

I am using ASP.NET MVC 3.
Can someone please help me clarify what's happening here:
var person = new PersonRepository().Get();
var personViewModel = new PersonViewModel();
personViewModel.InjectFrom<LoopValueInjection>(person)
.InjectFrom<CountryToLookup>(person);
I have a grid on my Index view. Each row is an instance of a CategoryViewModel. So what I do is to get a list of all the categories and then map each Category to a CategoryViewModel, and then pass this list of CategoryViewModels to the view. Hou would I do a mapping like that?
IEnumerable<Category> categoryList = categoryService.GetAll();
I thought the following would work but it doesn't:
// Mapping
IList<CategoryViewModel> viewModelList = new List<CategoryViewModel>();
viewModelList.InjectFrom(categoryList);

Answer 1

AFAIK value injecter doesn't support automatic collection mapping like AutoMapper but you could use a simple LINQ expression and operate on each element:
IEnumerable<Category> categoryList = categoryService.GetAll();
IList<CategoryViewModel> viewModelList = categoryList
.Select(x => new CategoryViewModel().InjectFrom(x)).Cast<CategoryViewModel>()
.ToList();

Answer 2

//source list
IEnumerable<string> items = new string[] { "1", "2" };
// target list
List<int> converted = new List<int>();
// inject all
converted.InjectFrom(items);
And the extension method:
public static ICollection<TTo> InjectFrom<TFrom, TTo>(this ICollection<TTo> to, IEnumerable<TFrom> from) where TTo : new()
{
foreach (var source in from)
{
var target = new TTo();
target.InjectFrom(source);
to.Add(target);
}
return to;
}
ICollection<T> is the interface that got least features but a Add method.
Update
An example using more proper models:
var persons = new PersonRepository().GetAll();
var personViewModels = new List<PersonViewModel>();
personViewModels.InjectFrom(persons);
Update - Inject from different sources
public static ICollection<TTo> InjectFrom<TFrom, TTo>(this ICollection<TTo> to, params IEnumerable<TFrom>[] sources) where TTo : new()
{
foreach (var from in sources)
{
foreach (var source in from)
{
var target = new TTo();
target.InjectFrom(source);
to.Add(target);
}
}
return to;
}
Usage:
var activeUsers = new PersonRepository().GetActive();
var lockedUsers = new PersonRepository().GetLocked();
var personViewModels = new List<PersonViewModel>();
personViewModels.InjectFrom(activeUsers, lockedUsers);

Answer 3

Use this function definition
public static object InjectCompleteFrom(this object target, object source)
{
if (target.GetType().IsGenericType &&
target.GetType().GetGenericTypeDefinition() != null &&
target.GetType().GetGenericTypeDefinition().GetInterfaces() != null &&
target.GetType().GetGenericTypeDefinition().GetInterfaces()
.Contains(typeof(IEnumerable)) &&
source.GetType().IsGenericType &&
source.GetType().GetGenericTypeDefinition() != null &&
source.GetType().GetGenericTypeDefinition().GetInterfaces() != null &&
source.GetType().GetGenericTypeDefinition().GetInterfaces()
.Contains(typeof(IEnumerable)))
{
var t = target.GetType().GetGenericArguments()[0];
var tlist = typeof(List<>).MakeGenericType(t);
var addMethod = tlist.GetMethod("Add");
foreach (var sourceItem in source as IEnumerable)
{
var e = Activator.CreateInstance(t).InjectFrom<CloneInjection>(sourceItem);
addMethod.Invoke(target, new[] { e });
}
return target;
}
else
{
return target.InjectFrom(source);
}
}

Answer 4

For those like me who prefer shortest notations possible
public static ICollection<TTarget> InjectFromList<TTarget, TOrig>(this ICollection<TTarget> target, ICollection<TOrig> source) where TTarget : new()
{
source.Select(r => new TTarget().InjectFrom(r))
.Cast<TTarget>().ToList().ForEach(e => target.Add(e));
return target;
}
public static ICollection<TTarget> InjectFromList<TTarget, TOrig>(this ICollection<TTarget> target, params ICollection<TOrig>[] sources) where TTarget : new()
{
sources.ToList().ForEach(s => s.ToList().Select(r => new TTarget().InjectFrom(r))
.Cast<TTarget>().ToList().ForEach(e => target.Add(e)));
return target;
}

Answer 5

Create a generic list mapper:
public class ValueMapper
{
public static TResult Map<TResult>(object item) where TResult : class
{
return item == null ? null : Mapper.Map<TResult>(item);
}
public static IEnumerable<TResult> MapList<TResult>(IEnumerable<object> items) where TResult : class
{
return items?.Select(i => Mapper.Map<TResult>(i));
}
}
Now you can reference the ValueMapper class wherever you want, and call both Map and MapList
var mydtos = ValueMapper.MapList<MyDto>(dtos);
var mydto = ValueMapper.Map<MyDto>(dto);