ValueInjecter with IQueryable<T>

Question

I need to map IQueryable<User> to IQueryable<SimpleUser> with ValueInjecter.

Is this possible?

I tried:

return userRepo.GetUsers()
               .Select(o => new SimpleUser().InjectFrom(o))
               .Cast<SimpleUser>();

But this cannot be translated to a stored expression...well, the method InjectFrom.

Can automapper do this?

I want something similar to this:

return from i in userRepo.GetUsers()
      select new SimpleUser{
            i.UserId,
            i.Name
      };

but with using some kind of mapper tool.

Answer 1

Convert the collection to objects before doing the select and it should work. Updated using PredicateBuilder to show filtering and paging and Dynamic LINQ for sorting.

var predicate = new PredicateBuilder<User>.True();
if (!string.IsNullOrEmpty( typeFilter ))
{
    predicate = predicate.And( u => u.Type == typeFilter );
}
if (!string.IsNullOrEmpty( nameFilter ))
{
    predicate = predicate.And( u => u.Name.StartsWith( nameFilter ));
}

// assumes sortColumn matches one of your user properties and
// sortDirection is either "ASC" or "DESC"
string sortOrder = string.Format( "{0} {1}", sortColumn, sortDirection ); 

return userRepo.GetUsers()
               .Where( predicate )
               .OrderBy( sortOrder )
               .Skip( (page-1) * usersPerPage )
               .Take( usersPerPage )
               .ToList()  // force the query and make these objects
               .Select(o => new SimpleUser().InjectFrom(o))
               .Cast<SimpleUser>();