How To: Customizing alert emails using IAlertNotifyHandler
In my post last week I talked about customizing alert notifications and alert templates. Sometimes you need to go further and create an alert handler. This week I’d like to share a code sample from Rashid Aga, one of our escalation engineers. His sample demonstrates how to intercept and modify alert mails using the IAlertNotifyHandler interface.
Problem:
==============
There are issues with particular field names like ItemName which will be truncated in an alert email at 70 characters. There can also be situations where you want to embed additional content in the email or change the layout and email appearance altogether.
Solution:
==============
Make use of the IAlertNotifyHandler interface to intercept the email and modify it.
We can create our own class that inherits from the IAlertNotifyHandler interface and uses the OnNotification method. This will allow you to intercept the outgoing alert emails and modify them. We can access most of the properties for the alert and with some xml parsing and SharePoint object model code, we can extract all the information we need to build up the email. We can then construct the HTML stub to display the email based on your requirements and send the email out using SharePoint’s SendMail functionality.
Steps:
I have included the sample code below along with the steps to set up the scenario. I have formatted the output of my code to resemble the default alert template emails as close as possible, you can customize it further to suit your needs.
1 Create a class project that inhertits from the IAlertNotifyHandler interface. Include the Microsoft.SharePoint and Microsoft.SharePoint.Utilities namespaces in the project.
This is the code for the class:
public class Class1:IAlertNotifyHandler
{
#region IAlertNotifyHandler Members
public bool OnNotification(SPAlertHandlerParams ahp)
{
try
{
SPSite site = new SPSite(ahp.siteUrl+ahp.webUrl);
SPWeb web = site.OpenWeb();
SPList list=web.Lists[ahp.a.ListID];
SPListItem item = list.GetItemById(ahp.eventData[0].itemId) ;
string FullPath=HttpUtility.UrlPathEncode(ahp.siteUrl+"/"+ahp.webUrl+"/"+list.Title+"/"+item.Name);
string ListPath = HttpUtility.UrlPathEncode(ahp.siteUrl + "/" + ahp.webUrl + "/" + list.Title);
string webPath=HttpUtility.UrlPathEncode(ahp.siteUrl+"/"+ahp.webUrl);
string build = "";
if (ahp.eventData[0].eventType==1)
eventType="Added";
else if(ahp.eventData[0].eventType==2)
eventType="Changed";
else if(ahp.eventData[0].eventType==3)
eventType="Deleted";
build = "<style type=\"text/css\">.style1 { font-size: small; border: 1px solid #000000;"+
"background-color: #DEE7FE;}.style2 { border: 1px solid #000000;}</style></head>"+
"<p><strong>"+ item.Name.ToString() +"</strong> has been "+eventType +"</p>"+
"<table style=\"width: 100%\" class=\"style2\"><tr><td style=\"width: 25%\" class=\"style1\">"+
"<a href="+ webPath +"/_layouts/mysubs.aspx>Modify my Settings</a></td>"+
"<td style=\"width: 25%\" class=\"style1\"> <a href="+ FullPath +">View "+item.Name+"</a></td>"+
"<td style=\"width: 25%\" class=\"style1\"><a href=" + ListPath + ">View " + list.Title + "</a></td>" +
" </tr></table>";
string subject=list.Title.ToString() ;
SPUtility.SendEmail(web,true , false, ahp.headers["to"].ToString(), subject,build);
return false;
}
catch (System.Exception ex)
{
return false;
}
}
#endregion
}
2. GAC the dll.
3. Make a copy of the alertTemplates.xml file found at this location: C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\12\TEMPLATE\XML. Always work with a copy of AlertTemplates.xml, not the original.
4. Call this new file CustomAlertTemplates and save the file. Edit the file and search for the keyword properties:
Include these additional lines into the properties block:
<NotificationHandlerAssembly>AlertHandler, Version=1.0.0.0, Culture=neutral, PublicKeyToken=d59ecf2a3bd66904</NotificationHandlerAssembly>
<NotificationHandlerClassName>AlertHandler.Class1</NotificationHandlerClassName>
<NotificationHandlerProperties></NotificationHandlerProperties>
The entire stub should look like this now:
<Properties>
<ImmediateNotificationExcludedFields>ID;Author;Editor;Modified_x0020_By;Created_x0020_By;_UIVersionString;ContentType;TaskGroup;IsCurrent;Attachments;NumComments;</ImmediateNotificationExcludedFields>
<DigestNotificationExcludedFields>ID;Author;Editor;Modified_x0020_By;Created_x0020_By;_UIVersionString;ContentType;TaskGroup;IsCurrent;Attachments;NumComments;</DigestNotificationExcludedFields>
<NotificationHandlerAssembly>AlertHandler, Version=1.0.0.0, Culture=neutral, PublicKeyToken=d59ecf2a3bd66904</NotificationHandlerAssembly>
<NotificationHandlerClassName>AlertHandler.Class1</NotificationHandlerClassName>
<NotificationHandlerProperties></NotificationHandlerProperties>
</Properties>
Include this xml stub in each alert template section you want in the alert template file.
5. Run this command from C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\BIN: stsadm -o updatealerttemplates -filename "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\12\TEMPLATE\XML\customalerttemplates.xml" -url <your sharepoint site url>
6. Run this command: stsadm -o setproperty -pn job-immediate-alerts -pv "every 1 minutes" so that you can see the log file come back in one minute. Be sure to set the time back after testing.
7. Make sure you have SharePoint already configured for outgoing emails.
8. Make sure that you have alerts for the document library turned on if you are testing with the document library.
9. Run this command from the command prompt: iisreset
10. Run this command from the command prompt: services.msc
11. From the services window, restart the Windows SharePoint Services Timer.
Your custom email alert handler should be configured at this point. Create a new alert and you should get the updated custom email.
Once again, my thanks to Rashid for this sample.