Event receiver itemupdating beforeproperties
Typically, before events are performed for Data Validation, as methods are triggered even before List events are fired and Share Point updates the Content Database.
All the Before Events are synchronous events which are executed in the same thread that a triggering action occurs.
The event receivers are bound to the lists in Feature events using C# code instead of the conventional XML method which uses the file.
NOTE: You could also bind an event receiver to a specific list instance using XML by replacing the List Template ID element with List Url.
However, in many cases, we only want our event receivers attached to specific list instances.
It turns out that the problem I describe in this article ONLY occurs if the event receiver is NOT registered *using app authentication*, e.g. If the RER is registered using *user authentication*, e.g.Feel free to skip forward if you’re familiar with this territory.For those just starting out with Remote Event Receivers (or Share Point apps/remote code in general), it’s worth noting that an app is required for any form of remote code.Solution Most of the sharepoint developer first thought will be eventhandler.When you start diving into deep you will realise that some of the object web developers love to use are you try to access the object like Http Context and SPContext it will be null.