In Share Point 2010 new improvements are made for better event receiving management.
Few new event handlers are added for site, web, list, listitems etc.
But when an Item is updated, you need to keep track of if the Approving status field value is changed, if so then u need to send notification.
However, you can only get the old approval status field value in Item Updating event, but you don’t want to send notification in Item Updating. First we need an List Event Receiver that will listen three events of the list: Item Added, Item Upating and Item Updated.
Unfortunately, that makes your project like the Titanic.
I don’t mean that it’s largest and most luxurious application every written, but rather that you may be cruising headlong into a nasty rendezvous with an iceberg that could deal a severe blow to your project.
But the Share Point Object Model doesn’t have the extensibility at this point where approving status changes.
If not, kudos to you for tackling the object model with reckless abandon.
Sometimes that is the most exciting way to learn, but for those less adventurous I will briefly cover the topic here.
So when user add/edit an item and as part of the add/edit if approval status field get updated then which events to fire? So consider now the problem we’re going to talk about.
We need a notification system where we need to send notification to the approver or user (who is waiting for approval) on approval status change.