linq2sql missing event model? - linq-to-sql

Question

How come the "Table" classes Generated in the Dbml do not contain useful events like
OnBeforeInsert
OnBeforeUpdate
OnAfterInsert
etc.
Am I missing something?
This question is related to frustration trying to set timestamp columns.
UPDATE
I created the following method of doing this neatly what does everyone think?
public class Model
{
internal virtual void OnBeforeInsert()
{
}
internal virtual void OnBeforeUpdate()
{
}
}
public partial class DbDataContext
{
public override void SubmitChanges(System.Data.Linq.ConflictMode failureMode)
{
foreach (var insert in this.GetChangeSet().Inserts)
{
if (insert is Model)
{
((Model)insert).OnBeforeInsert();
}
}
foreach (var update in this.GetChangeSet().Updates)
{
if (update is Model)
{
((Model)update).OnBeforeUpdate();
}
}
base.SubmitChanges(failureMode);
}
}
public partial class Address : Model
{
internal override void OnBeforeInsert()
{
var created = DateTime.Now;
this._Modified = created;
this._Created = created;
}
}

Answer 1

I had a similar issue like this recently.
There is a partial method in the generated class for "OnValidate". Simply declaring the method in your partial will force it to be called (vb.net does not support partial methods like c#) or in c# simply declare a partial method.
The method is passed a System.Data.Linq.ChangeAction enum that is either: Delete, Insert, Update, or None.
Below is a sample of what you did using the built in partial method.
public partial class Address
{
private partial void OnValidate(System.Data.Linq.ChangeAction action)
{
if (action == System.Data.Linq.ChangeAction.Insert)
{
var created = DateTime.Now;
this._Modified = created;
this._Created = created;
} else if (action == System.Data.Linq.ChangeAction.Update) {
this._Modified = DateTime.Now;
}
}
}