Custom binding and filtering on DTO

[Pieter]

I want to use custom binding on a grid which displays a DTO. I'm using nHibernate to load information from the database. However, I'm getting the following error message:

System.Exception: Could not determine member from IIF((item != null), item.Status, Onbekend)

The field 'Status' comes from the DTO, but is named differently in the original entity. However, filtering as in the demo doesn't work when I do this:

if (command.FilterDescriptors.Any())
 {
    query = query.Where(ExpressionBuilder.Expression<MyDto>(command.FilterDescriptors));
}

The original queryover is structured as follows:

var query = Session.QueryOver<OriginalEntity>(() => entityAlias)
                .SelectList(.....)
                .TransformUsing(Transformers.AliasToBean<MyDto>());

How do I instruct the ExpressionBuilder to work on the DTO instead of on the original entity?

[Rosen]

Hello Pieter,

Is moving the projection into the DTO at the end after the filtering, sorting etc. makes any difference?

Best wishes,
Rosen
the Telerik team

[Pieter]

Rosen,

I don't really want to do that, as the entity has a lot of child collections which would be retrieved causing the performance of the query to degrade. The projection makes sure only the relevant portions of the entity are retrieved from the database.
I have modified the code to check the MemberName in the FilterDescriptor and based on that name I add a Where-clause to the query. It's a bit more work but it gets the job done.