GridView doesn't cause NHibernate proxy to load relationships

Question

I'm currently learning NHibernate and I would like to data-bind to Web controls (i.e. GridView).

In my current example I am using Fluent NHibernate to map two tables to their business objects (Project and ProjectStatus). I also have a "Project has a ProjectStatus" (many-to-one) relationship.

Structure of Project class:

Project.ID
Project.Name
Project.ProjectStatus.Name
Project.ProjectStatus.Description

When I bind a list of Project objects (with lazy="proxy") to a GridView, the GridView does not trigger the load of the referenced table. As a result the fields Name and Description of ProjectStatus are left out by the GridView control.

Is there a way of having true lazy loading in combination with a data-bound GridView?

Thanks in advance.

Answer 1

Are you storing your ISession in the request context and flushing it at the end of the request? If not, you should start a new session in the begin_ request method of the global.asax.cs, store it in request context, then grab it back in the end_request method, and flush it.

Answer 2

This should work without any problems. I suspect the problem is in the data binding itself not accessing the properties of a child object. How are you binding to the ProjectStatus properties? As far as I know, you can't directly bind to child objects. You have to set values in an OnRowDataBound event handler or by using Eval.

I would first create an OnRowDataBound handler and break on a DataRow. Examine e.Row.DataItem in the immediate window to verify that the child object is being loaded. If it is, then the problem lies with the binding.