Update custom alert template - SharePoint 2013

I am not able to update custom alert template on SharePoint list,Converts all subscribed or existing alerts of the list to the custom alert template.Update Existing/change custom alert template for SharePoint list.

below STSADM command works for SP2010 but not for 2013.
stsadm -o updatealerttemplates -url http://webapp/sitecol/ -filename "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\15\TEMPLATE\XML\custom_alerttemplates.xml"


Here is the solution:
Server side:

public static void AlertTemplate(SPWeb webElevated, SPList oList )

        {           

            SPAlertTemplateCollection col = new SPAlertTemplateCollection(SPWebService.ContentService);

            foreach (SPAlertTemplate spAlert in col)

            {

              //<AlertTemplate Type="List" Default="True" Name ="My Template">

                //above is based on your custom template called custom_alerttemplates.xml

                if (spAlert.Name == "My Template")

                {

                try

                    {

                        webElevated.AllowUnsafeUpdates = true;                     

                        oList.AlertTemplate = spAlert;

                        oList.Update();

                        webElevated.AllowUnsafeUpdates = false;

                    }

                    catch (Exception ex)

                    {

                        webElevated.AllowUnsafeUpdates = false;

                    }

                break;

                }

            }        

         

        }

PowerShell:
add-pssnapin Microsoft.SharePoint.PowerShell -erroraction silentlycontinue
$contentService = [Microsoft.SharePoint.Administration.SPWebService]::ContentService
$AlertsTemplateCollection = new-object Microsoft.SharePoint.SPAlertTemplateCollection($contentService)
$spWeb = Get-SPWeb -Identity 'http://site/webUrL/'
$splists = $spWeb.lists
$alertslist = $splists["YourList"]
Write-Host  $alertslist

$alertslist.AlertTemplate
$alertslist.AlertTemplate = $AlertsTemplateCollection["MyTemplate name based on .xml file"]
$alertslist.Update()
Write-Host  $alertslist.AlertTemplate
$alertslist.AlertTemplate
$spWeb.Dispose()

Note: Once you execute above code, you should unsubscribe and subscribe alerts is mandatory - see the program below.


Complete Documented Notes:

Verify the “MyOrg_alerts.xml”

Go to the location of file system: C:\Program Files\Common Files\microsoft shared\Web Server Extensions\15\TEMPLATE\XML and verify the file name “MyOrg_alerts.xml” is available.

Register/add the “MyOrg_alerts” template into SharePoint environment

 STSADM command below:

stsadm -o updatealerttemplates -url "http://yourSiteUrl/" -filename "C:\Program Files\Common Files\microsoft shared\Web Server Extensions\15\TEMPLATE\XML\MyOrg_alerts.xml"

Note: The URL yellow in color may vary based on the server, please change accordingly.

Update template to the library

Note: The URL yellow in color may vary based on the server, please change accordingly.

add-pssnapin Microsoft.SharePoint.PowerShell -erroraction silentlycontinue

$contentService = [Microsoft.SharePoint.Administration.SPWebService]::ContentService

$AlertsTemplateCollection = new-object Microsoft.SharePoint.SPAlertTemplateCollection($contentService)

$spWeb = Get-SPWeb -Identity 'http://yourSiteUrl/'

$splists = $spWeb.lists

$alertslist = $splists["MyOrg Events"]

Write-Host $alertslist

Write-Host $alertslist.AlertTemplate

$alertslist.AlertTemplate = $AlertsTemplateCollection["MyOrg Template"]

$alertslist.Update()

Write-Host $alertslist.AlertTemplate

$spWeb.Dispose()

End User /Subscriber Action:

If already subscribed: please do un-subscribe and subscribe the alerts.

Update If Already Existing users:

add-pssnapin Microsoft.SharePoint.PowerShell -erroraction silentlycontinue

$contentService = [Microsoft.SharePoint.Administration.SPWebService]::ContentService

$AlertsTemplateCollection =  new-object Microsoft.SharePoint.SPAlertTemplateCollection($contentService)

$spWeb = Get-SPWeb -Identity http://yourSiteUrl/

$splists = $spWeb.lists

$alertslist = $splists["MyOrg Events"]

$alerts = $spWeb.Alerts

if ($alerts.Count -gt 0)

{

       $myalerts = @()

       foreach ($alert in $alerts)

       {       

         if( $alert.ListID -eq $alertslist.ID)

         {

             # echo "Updating" + $alert.AlertTemplateName

                       $alert.AlertTemplate = $AlertsTemplateCollection["MyOrg Template"]

                       $alert.Update()

                     #      echo "Updated $alert.AlertTemplateName"

         }

         

             

       }

}

$spWeb.Dispose()

Server Side- C#

  public static void ConvertsAllSubscribedUsersToNewlyAddedTemplate(SPWeb webElevated)

        { // Converts all subscribed or existing alerts of the list to the custom alert template //

                        

       SPList lstCorporate = webElevated.Lists.TryGetList("MyOrg Events"); 

       foreach (SPAlert alert in webElevated.Alerts)

        {                   

           if (alert.ListID == lstCorporate.ID)

              {                        

                 alert.AlertTemplate = lstCorporate.AlertTemplate;

                 alert.Update();

              }

        }           

         

     }