How to easly convert linq result to Business Object Collection <T> - linq

Question

I have Business Object Collection
I'd like to filter rows using linq, but noticed it returns IEnumerable what can not be cast then to my BOC
E.g I cannot do that
BOC <Client> bocCLients = (BOC <Client>)
from C in ClientsColl where C.ClientId == 100 select C
I've resolved that by looping by linq results and adding returned object to my original collection.
I wonder if there is simpler way?

Answer 1

var bocCLients = ClientsColl.Where(c => c.ClientId == 100).ToList();
Or
var bocCLients = new BOC<Client>(ClientsColl.Where(c => c.ClientId == 100));
Edit
Or maybe an AddRange extension
public static void AddRange<T>(this ICollection<T> colSource, IEnumerable<T> collection)
{
if (colSource is List<T>)
((List<T>)colSource).AddRange(collection); //If List use build in optimized AddRange function
else
{
foreach (var item in collection)
colSource.Add(item);
}
}

Answer 2

This looks like a perfect opportunity to create an extension method. From looking at your question, it appears that ClientsColl already contains objects of type Client. In this case, your solution of a foreach loop is ideal. However, you can encapsulate that solution into an extension method and make it reusable and easy to read.
Here's an example of how it would look like:
public static BOC<T> ToBOC<T>(this IEnumerable<T> sourceCollection)
{
var boc = new BOC<T>();
foreach (T item in sourceCollection)
{
boc.Add(item);
}
return boc;
}
Using this extension method, you would just write your query as follows:
BOC<Client> bocClients =
(
from C in ClientsColl
where C.ClientID == 100
select C
).ToBOC();
EDIT:
To follow up on the idea of the more generic extension method to ICollection, but keeping in line the original question which was to perform a sort of Cast to a specific type of collection, and now having the new information that BOC implements ICollection, here is a more generic extension method and usage to perform the job:
public static TCollection ToICollection<T, TCollection>(this IEnumerable<T> sourceCollection)
where TCollection : ICollection<T>, new()
{
TCollection col = new TCollection();
foreach (T item in sourceCollection)
{
col.Add(item);
}
return col;
}
And usage:
BOC<Client> bocClients2 =
(
from C in ClientsColl
where C.ClientID == 100
select C
).ToICollection<Client, BOC<Client>>();
Does this look more useful? Let me know what you think.