Modify SPListItem fields with vars from the Session in the itemAdding or itemAdded events
Some time ago I tried to alter a field of a SPListItem right after the moment that the item has been created. A var was stored in the Session so it could be used on the newly created SPListItem (itemAdded).
NOT!
I figured out that the HttpContext isn't available when during the ItemAdded event. When using the itemAdding event, the HttpContext is available, but the item that will be created, isnt. The SPFeatureReceiverProperty.SPListItem is null, because the item is not yet created. After reading the MSDN documentation I figured out that the SPFeatureReceiverProperties Afterproperties can be used to store a value, which will be applied right after the item is created.
below is an example:
using System;
public class ItemEventReceiver
{
public ItemEventReceiver()
{
hContext = HttpContext.Current;
}
///
/// overrides default ItemAdded
///
///
public override void ItemAdded(SPItemEventProperties properties)
{
Debug.WriteLine("ItemAdded");
CheckHContextAndSPListItem(properties.ListItem);
base.ItemAdded(properties); }
///
/// overrides the standard ItemAdding
///
///
public override void ItemAdding(SPItemEventProperties properties)
{
string internalFieldName = null;
string FIELD_NAME = "Foo";
SPFieldLookupValue lookupField = null;
Debug.WriteLine("ItemAdding");
CheckHContextAndSPListItem(properties.ListItem);
using (SPWeb web = properties.OpenWeb())
{
internalFieldName = web.Lists[properties.ListId].Fields[FIELD_NAME].InternalName; }
// example for adding a value to a SPListItem property
string tempValue = "foo";
properties.AfterProperties[internalFieldName] = tempValue;
}
///
/// checks the values of hContext and SPListItem
///
/// SPListItem out of the SPItemEventProperties
private static void CheckHContextAndSPListItem(SPListItemlistItem)
{
if (HttpContext.Current == null)
Debug.WriteLine("hContext is null");
else
Debug.WriteLine("hContext is available");
if (listItem == null)
Debug.WriteLine("listItem is null");
else
Debug.WriteLine("listItem is available");
}
}