EventHandlers saved to databases.
- by Stacey
In a database application (using Sql Server right now, in C#, with Entity Framework 4.0) I have a situation where I need to trigger events when some values change. For instance assume a class "Trackable".
class Trackable
{
string Name { get; set; }
int Positive { get; set; }
int Negative { get; set; }
int Total { get; set; }
// event OnChanged
}
Trackable is represented in the database as follows;
table Trackables
Id | guid
name | varchar(32)
positive | int
negative | int
Total is of course, calculated at runtime.
When a trackable event changes, I want to inspect its previous value, and then see what it is changing to, and be capable of reacting accordingly. However different trackables need to trigger different events (to avoid a huge, massive cascading switch/if block).
If this were just only C# code it would be easy - but they have to be saved to the database. I can't divide up each different trackable into a different table/class, that would be silly - they are all identical, but the event raised is different based on how they are made.
So I guess my question is, is there any way to store an event handler in a database such that..
Trackable t1 = new Trackable()
{
Name = "Trackable1"
OnChange += TrackableChangedEventHandler(OnTrackable1Change)
}
Trackable t2 = new Trackable()
{
Name = "Trackable2",
OnChange += TrackableChangedEventHandler(OnTrackable2Change)
}
