To Create a Custom Destination Type

In MYOB Advanced or an MYOB Advanced Framework-based application, you can send push notifications to the notification destinations, which can be of a predefined type (which is webhook, message queue, SignalR hub, commerce push destination) or of a custom type, which you can implement in the code of the application.

The notification destination of a custom type can be implemented in a project of your MYOB Advanced extension library. To create a custom destination, follow the instructions in this topic.

To Create a Custom Destination Type

In a project of your MYOB Advanced extension library, define a class that implements the PX.PushNotifications.NotificationSenders.IPushNotificationSender interface, which is a sender of push notifications.
In the class that implements the IPushNotificationSender interface, implement the following methods and properties of the interface:
- The Address property, which is the address to which the system should send notifications. A user specifies the value of this property in the Address box on the Push Notifications (SM302000) form. The property uses the following syntax.
```
string Address { get; }
```
- The Name property, which is the name of the notification destination. A user specifies the value of this property in the Destination Name box on the Push Notifications (SM302000) form. Use the following syntax for the property.
```
string Name { get; }
```
- The Send method, which sends a notification synchronously and uses as the parameters the notification to be sent and a cancellation token. The method uses the following syntax.
```
void Send(
  NotificationResultWrapper results, 
  CancellationToken cancellationToken
);
```
- The SendAndForget method, which sends a notification without blocking the current thread. We recommend that you use HostingEnvironment.QueueBackgroundWorkItem in the method implementation to delegate the execution to a parallel thread. The following code shows a sample implementation of the method.
```
using System;
using System.Threading;
using PX.PushNotifications;
using PX.PushNotifications.NotificationSenders;

public void SendAndForget(
  NotificationResultWrapper result, 
  CancellationToken cancellationToken, 
  Action onSendingFailed, 
  Action finalizer)
{
  try
  {
    Send(result, cancellationToken);
  }
  catch (Exception e)
  {        
    onSendingFailed($"Send to target {Name} failed: ({e.Message})");
  }
  finally
  {
    finalizer();
  }
}
```
Define a class that implements the PX.PushNotifications.NotificationSenders.IPushNotificationSenderFactory interface, which creates a sender of push notifications.
In the class that implements the IPushNotificationSenderFactory interface, implement the following methods and properties of the interface:
- The Create method, which creates a sender and uses as the parameters the destination address, the name of the notification destination, and the additional parameters (such as a header for an HTTP address). Use the following syntax for the method.
```
IPushNotificationSender Create(
  string address, 
  string name, 
  IDictionary<string, object> additionalParameters
);
```
- The Type property, which is a string identifier of the destination type that is exactly four characters long. The value of this property is stored in the database. The property uses the following syntax.
```
string Type { get; }
```
- The TypeDescription property, which is a string label of the destination type. A user selects the value of this property in the Destination Type box on the Push Notifications (SM302000) form. Use the following syntax for the property.
```
string TypeDescription { get; }
```
Build the project of your MYOB Advanced extension library.
Run MYOB Advanced and test the new destination type.