ItemEventReceiver - ItemDeleting not working with a document library and referencing list

Question

I have a custom list that has a GUID column which refers to the UniqueId of a document in a document library. Every time I upload a document, it should add an entry in this list and populate the column with this document GUID column.

List 1: Document Library, its items UniqueId is stored in the DocumentId column of the second list.
List 2: A custom list with a column called DocumentId where it's value is the document's UniqueId (GUID).

I have used an item receiver to do this, the code is shown below (working). This side works fine, the issue is when I want to do the opposite.

 public override void ItemDeleting(SPItemEventProperties properties)
    {
        using (SPWeb web = properties.OpenWeb())
        {
            SPListItem documentItem = properties.ListItem;
            string listUrl = SPUtility.ConcatUrls(web.ServerRelativeUrl, "Lists/PortalLinks");
            // Get the PortalLinks list
            SPList portalLinksList = web.GetList(listUrl);
            // Gets the matching items by CAML
            SPQuery linkQuery = new SPQuery();
            linkQuery.Query = string.Format("<Where><Eq><FieldRef Name='DocumentItemId' /><Value Type='Guid'>{0}</Value></Eq></Where>", documentItem.UniqueId);
            SPListItemCollection linkItemsMatchingGuid = portalLinksList.GetItems(linkQuery);

            //add the main text to the stringbuilder
            batchString.Append("<?xml version=\"1.0\" encoding=\"UTF-8\"?><Batch>");
            foreach (SPListItem item in linkItemsMatchingGuid)
            {
                batchString.Append("<Method>");
                batchString.Append("<SetList Scope=\"Request\">" + Convert.ToString(item.ParentList.ID) + "</SetList>");
                batchString.Append("<SetVar Name=\"ID\">" + Convert.ToString(item.ID) + "</SetVar>");
                batchString.Append("<SetVar Name=\"Cmd\">Delete</SetVar>");
                batchString.Append("</Method>");
            }
            batchString.Append("</Batch>");
            web.ProcessBatchData(batchString.ToString());
        }
        base.ItemDeleting(properties);
    }

If I delete the link item associated with a document, I also want to delete this document. So I went and added an ItemDeleting event receiver to this linked list but for some reason I can't seem to get this side to work.

Here is the ItemDeleting code to 'try' and delete the referencing document. (Not working)

 public override void ItemDeleting(SPItemEventProperties properties)
    {
        using (SPWeb web = properties.OpenWeb())
        {
            // Get the matching list item beign deleted.
            SPListItem linkItem = properties.ListItem;
            Guid parentId = new Guid(linkItem["DocumentItemId"].ToString());
            // Get the list of documents.
            string documentLibraryUrl = SPUtility.ConcatUrls(web.ServerRelativeUrl, "/Documents");
            SPList documentLibrary = web.GetList(documentLibraryUrl);
            SPListItemCollection documents = documentLibrary.Items;

            StringBuilder batchString = new StringBuilder();
            batchString.Append("<?xml version=\"1.0\" encoding=\"UTF-8\"?><Batch>");
            foreach (SPListItem item in documents)
            {
                if (item.UniqueId == parentId)
                {
                    batchString.Append("<Method>");
                    batchString.Append("<SetList Scope=\"Request\">" + Convert.ToString(item.ParentList.ID) + "</SetList>");
                    batchString.Append("<SetVar Name=\"ID\">" + Convert.ToString(item.ID) + "</SetVar>");
                    batchString.Append("<SetVar Name=\"Cmd\">Delete</SetVar>");
                    batchString.Append("</Method>");
                }
            }
            batchString.Append("</Batch>");
            web.ProcessBatchData(batchString.ToString());
        }
        base.ItemDeleting(properties);
    }

I have tried the following before with no luck either:

Looping through the list and deleting the item one by one (I read its not very efficient so I switched to batch delete).

Result

Deleting the document removes the link in the list.

Deleting the link, however does NOT remove the referring document but I want it to.

Please let me know if there is a better way to do this.

Thanks.

Answer 1

HandleEventFiring handleEventFiring = new HandleEventFiring();

                    handleEventFiring.DisableHandleEventFiring();
                    try
                    {
                        var parentDoc = documentLibrary.GetItemByUniqueId(parentId);
                        parentDoc.Delete();    
                     }
                    finally
                    {
                        handleEventFiring.EnableHandleEventFiring();
                    }

to disallow multiple firing of the delete event.

Answer 2

Have you tried the obvious instead of looping through all document and building a batch update to delete a single document by it's unique id?

Something like this (after the line SPList documentLibrary = web.GetList(documentLibraryUrl);:

var parentDoc = documentLibrary.GetItemByUniqueId(parentId);
parentDoc.Delete();