Sharepoint 2013 Event Receiver ItemUpdating - detect Attachments

Question

I've been looking for a way to detect changes on the attachments of an item using synchronous event receivers in SharePoint 2013 developed in C#.

The ItemAdding event is not relevant as it's not a problem if attachments are uploaded at the same moment the item is created, however, the event ItemUpdating is more relevant. Indeed, I would like to be able to update another field if one (or more) attachment is added or deleted during the synchronous event only. Asynchronous events are not an option.

I tried the solution provided here without any luck :

When an attachment gets added, Request.Files.Count is higher or equal to 1
When an attachment gets removed, it's equal to 1 if other attachments still exist on the item
When no changes are done, it's still equal to 1 if other attachments exist on the item.

Would you have any ideas how I can do it ?

Thank you in advance,

Kevin

EDIT 19 APRIL : After further investigation, I detected that an empty file was always sent in the Request.File, so I know now the reason why Request.File.Count was always at least equal to 1.

With a small piece of code added, I can detect one or more valid files are being added :

int attachCount = 0;  
HttpFileCollection fileCollection = curContext.Request.Files;  
for (int j = 0; j < fileCollection.Count; j++)
{
    HttpPostedFile file = fileCollection[j];
    if (file.ContentLength > 0)
    {
        attachCount++;
    }
}

Only thing left is how to detect that attachments has been removed when being in the ItemUpdating event, any ideas ?

Thank you in advance

Kevin Kevin · Accepted Answer · 2018-04-26T09:12:20

After a lot of searching, I used the ItemUpdated event to solve the problem of the attachments deleted with the number of attachments in a dedicated field. All is working as expected. The only down side is the fact that the user might have to wait a few seconds before seeing the impact of the attachment removal.

Sharepoint 2013 Event Receiver ItemUpdating - detect Attachments

1 Answers