How does Sharepoint Online Event Receivers work?

Question

I have created this Sandboxed Event Receiver on ItemAdding on a custom list.

It works on my on-premise server, but it does not work on Sharepoint Online aka. O365.

Anybody know how to create an Event Receiver in Sharepoint Online, I will be really thankful!

----- EDIT ----

using System;
using System.Security.Permissions;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Security;
using Microsoft.SharePoint.Utilities;
using Microsoft.SharePoint.Workflow;

namespace Change_Title_Event.Change_Title
{
    /// <summary>
    /// List Item Events
    /// </summary>
    public class Change_Title : SPItemEventReceiver
    {
       /// <summary>
       /// An item is being added.
       /// </summary>
       public override void ItemAdding(SPItemEventProperties properties)
       {
           properties.AfterProperties["Title"] = "Kevin: Changed by event receiver at" + DateTime.Now.TimeOfDay.ToString();
           base.ItemAdding(properties);
       }


    }
}

Elements.xml

<?xml version="1.0" encoding="utf-8"?>
<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
  <Receivers ListTemplateId="100">
      <Receiver>
        <Name>Change_TitleItemAdding</Name>
        <Type>ItemAdding</Type>
        <Assembly>$SharePoint.Project.AssemblyFullName$</Assembly>
        <Class>Change_Title_Event.Change_Title.Change_Title</Class>
        <SequenceNumber>10000</SequenceNumber>
      </Receiver>

  </Receivers>
</Elements>

Scope is Web and the Item is in the Feature.

-------- EDIT 2 ----------

using System;
using System.Security.Permissions;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Security;
using Microsoft.SharePoint.Utilities;
using Microsoft.SharePoint.Workflow;

namespace Change_Title_Event.Change_Title
{
    /// <summary>
    /// List Item Events
    /// </summary>
    public class Change_Title : SPItemEventReceiver
    {
       /// <summary>
       /// An item was added
       /// </summary>
       public override void ItemAdded(SPItemEventProperties properties)
       {
           base.ItemAdded(properties);
           properties.ListItem["Title"] = "Kevin: Changed by event receiver at" + DateTime.Now.TimeOfDay.ToString();
           properties.ListItem.Update();
       }


    }
}

This code works on on-premise, but do not work on Sharepoint Online.

Does somebody has a working solution (.wsp), that works on Sharepoint Online?

Answer 1

If your event receiver is working on your on-premise server, there is no reason it should not work on Office 365. Unless you are doing something from the Event Receiver which is not allowed in Sandbox. In that case, a SPException will be thrown.

There is really no "different" way to create Event Receivers for SharePoint online. I think that your Event Receiver might be firing, but there must be some error in the code for the Event Receiver. Can you please update your answer with code so that it would be easier to find out what might be going wrong?

Update:

Can you try the following code?

 public override void ItemAdding(SPItemEventProperties properties)
   {
       base.ItemAdding(properties);
       properties.ListItem["Title"] = "Kevin: Changed by event receiver at" + DateTime.Now.TimeOfDay.ToString();
       properties.ListItem.Update();
   }

Also, is there a reason why you are using the ItemAdd*ing* event instead of the ItemAdd*ed* event?

Answer 2

I wonder if it is because of your using references ? Try cutting your references and using statements to the bare minimum you need.

Answer 3

I think, in your code properties.ListItem.Update(); will throw error during ItemAdding Event.

Kevin,

I am able to see that in EDIT-2 you are using ItemAdded event, but in element.xml you have missed to input receiver for the same.

Answer 4

You first need to do GetItemByID on your list. and then update it.

public override void ItemAdded(SPItemEventProperties properties)
        {

this.EventFiringEnabled = false;
            base.ItemAdded(properties);

            SPList emp = properties.Web.Lists.TryGetList(Constants.PFSListCollectors);
            SPListItem item = emp.GetItemById(properties.ListItemId);

                item[Constants.ColNameCollectorsName] = Convert.ToString(item[Constants.ColNameName]).Split('#')[1];
                item.Update();

            this.EventFiringEnabled = true;
        }

Answer 5

in Elements.xml File Clange Receivers ListTemplateId="100" by:

Receivers ListUrl="YourSubsitename/CustomListName"

Also Activate the Feature in Manage Site Features