How to create a simple Remote Event Receiver for a Custom List in Office 365 SharePoint 2013 site

In this article, we’ll see how to create a remote event receiver for a custom list (in App Web) in SharePoint 2013 Online. The Remote Event Receivers are components (classes) that makes SharePoint Apps to respond to events that occur in SharePoint lists or items.

Create a new App in Visual Studio 2012 and name it as ‘CustomListEventReceiver’

Set the Office 365 SharePoint site for debugging the App and select App Type as SharePoint Hosted App

Now the app project is created. The next step is to create or set up a Custom List in the App.

Right Click –> Add New Item –> List and name it as ‘TestCustomList’

Select ‘Default(CustomList)’ for Create a custom list template and list instance of it –> Finish

Now the Custom List is created. The next step is to add the Remote Event Receiver.

Right Click –> Add New Item –> RemoteEventReceiver and name it as TestEventReceiver.

This creates a RemoteWeb Project containing .svc file listening for remote events . The whole ideas is that in SharePoint 2013, the event handling for Lists and Items happened outside of SharePoint in the WCF Service (inside RemoteWeb Project).

Select the following 3 events to be handled

Now you’ll see a remote event receiver project (.svc file inside it) created as the part of the Solution.

Remove the ClientId and ClientSecret from Web.Config file

<add key="ClientId" value="b0b7eb35-8980-4910-a3f6-f7129bb16466" />
<add key="ClientSecret" value="oVS2tUbGHbnWEQMPk2i5VvwdyOH04iiWJZmp0N9HXSE=" />

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Open the AppManifest.xml file and change the AppPrincipal to internal

<AppPrincipal>
   <Internal/>   
 </AppPrincipal>

Go to Project Properties in Visual Studio 2012 and set the following properties

Since this App is running in Office 365, we need to set an Azure Service Bus connection string is required for debugging the remote event receiver (.svc component). Otherwise, we’ll get this debugging error mentioned in one of my previous article.

Go to Elements.xml of default.aspx under Pages.xml.

Remove the following File tag in the Elements.xml

<File Path="PagesDefault.aspx" Url="Pages/Default.aspx" ReplaceContent="TRUE" />

Add the following File tag inside Elements.xml

 <File Path="PagesDefault.aspx" Url="Pages/Default.aspx" >
      <AllUsersWebPart WebPartZoneID="full" WebPartOrder="0">
        <![CDATA[ 
      <webParts>
      <webPart xmlns="http://schemas.microsoft.com/WebPart/v3">
      <metaData>
      <type
    name="Microsoft.SharePoint.WebPartPages.XsltListViewWebPart,
    Microsoft.SharePoint,Version=14.0.0.0,Culture=neutral,
    PublicKeyToken=71e9bce111e9429c" />
      <importErrorMessage>
      Cannot import this Web Part.
      </importErrorMessage>
      </metaData>
      <data>
        <properties>
          <property name="Title"
           type="string">TestCustomList</property>
          <property name="ListDisplayName"
           type="string">TestCustomList</property> 
           <property name="ChromeType"
           type="chrometype">TitleOnly</property>
        </properties>
      </data>
    </webPart>
  </webParts>
]]>
      </AllUsersWebPart>
    </File>

The above File element inserts an XSLST List View web part to render the list items of TestCustomList with the column name Title.

Open default.aspx and add the following webpart definition inside the PlaceHolderMain (just outside of the div containing <p> with id as message)

<WebPartPages:WebPartZone runat="server" FrameType="TitleBarOnly" ID="full" Title="loc:full" />

Open TestEventReceiver and implement the ProcessEvent(SPRemoteEventProperties properties) method for the ItemAdding and ItemDeleted events

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.SharePoint.Client;
using Microsoft.SharePoint.Client.EventReceivers;

namespace CustomListEventReceiverWeb.Services
{
    public class TestEventReceiver : IRemoteEventService
    {
        public SPRemoteEventResult ProcessEvent(SPRemoteEventProperties properties)
        {
            SPRemoteEventResult oResult = new SPRemoteEventResult();
                       
            

            switch (properties.EventType)
            {
                case SPRemoteEventType.ItemAdding:


                   
                    
                    oResult.ChangedItemProperties.Add("Title", properties.ItemEventProperties.AfterProperties["Title"] += "Sundar");
                    break;

                case SPRemoteEventType.ItemDeleting:
                    oResult.ErrorMessage = "You cannot delete this list item";
                    oResult.Status = SPRemoteEventServiceStatus.CancelWithError;
                    break;
            }


            return oResult;
        }

        public void ProcessOneWayEvent(SPRemoteEventProperties properties)
        {
            if (properties.EventType == SPRemoteEventType.ItemAdded)
            {
                //Do something here ...
            }
        }
    }
}