Callbacks on entity on created/updated

Question

I would like to know when entities in a certain database table are either created or updated. The application is essentially a CMS, and I need to know when changes are made to the content so that I can reindex them for searches.

I know that the autogenerated LINQ to EF class has overridable methods for when certain fields change, but I need to know when the whole object is created/updated, not just a single field. I tried putting it in OnCreated, only to find that meant OnObjectInitialized and not OnObjectInsertedIntoDBTable xD

I did some searching and came across this link. The "Entity State" section looks like its what I want, but I'm not sure how to use this information. Where do I override those methods?

Or perhaps there is a another/better way?

(I also need to know this for another part of the system, which will send notifications when certain content is changed. I would prefer this code to execute automatically when the insert/update occurs instead of placing it in a controller and hoping hoping I always call that method.)

Answer 1

You need to get ObjectStateEntry(s) from the ObjectStateManager property of the ObjectContect.

var objectStateEntries = this.ObjectStateManager.GetObjectStateEntries(); 

This entries contain every object state you've pulled down per context and what kind of actions where performed on them.

If you are using EF4 you can override the SaveChanges method to include this functionality. I've used this technique to audit every change that occurs in the database instead of triggers.